Title of Invention	'AXIAL FLOW HYDRAULIC TURBINE ELECTRIC GENERATOR SYSTEM"
Abstract	An axial flow hydraulic turbine electric generator system includes a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow, and having respective rotary impellers, and an electric generator arranged parallel with the plurality of unit axial flow hydraulic turbines in the direction of water flow, and driven by shaft outputs of the plurality of unit axial flow hydraulic turbines. This structure enables the use of mass-produced hydraulic turbines in axial flow hydraulic turbine electric generator systems with various specifications such as various heads, various flow rates, etc. The invention provides for an axial flow hydraulic turbine electric generator system, comprising; a fluid conduit pipe having a connecting portion for connecting with an upstream conduit and connecting portion for connection with a downstream conduit; a unit axial flow hydraulic turbine (300A, 300B) arranged in the fluid conduit pipe such that a shaft thereof is parallel to a direction of fluid flow and having a rotary impeller; and an electric generator arranged outside the fluid conduit pipe such that a shaft thereof is parallel to the fluid conduit pipe and driven by a shaft output of the unit axial flow hydraulic turbine (300A, 300B).

Title of Invention

'AXIAL FLOW HYDRAULIC TURBINE ELECTRIC GENERATOR SYSTEM"

Abstract

An axial flow hydraulic turbine electric generator system includes a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow, and having respective rotary impellers, and an electric generator arranged parallel with the plurality of unit axial flow hydraulic turbines in the direction of water flow, and driven by shaft outputs of the plurality of unit axial flow hydraulic turbines. This structure enables the use of mass-produced hydraulic turbines in axial flow hydraulic turbine electric generator systems with various specifications such as various heads, various flow rates, etc. The invention provides for an axial flow hydraulic turbine electric generator system, comprising; a fluid conduit pipe having a connecting portion for connecting with an upstream conduit and connecting portion for connection with a downstream conduit; a unit axial flow hydraulic turbine (300A, 300B) arranged in the fluid conduit pipe such that a shaft thereof is parallel to a direction of fluid flow and having a rotary impeller; and an electric generator arranged outside the fluid conduit pipe such that a shaft thereof is parallel to the fluid conduit pipe and driven by a shaft output of the unit axial flow hydraulic turbine (300A, 300B).

Full Text	TITLE OF THE INVENTION AXIAL FLOW HYDRAULIC TURBINE ELECTRIC GENERATOR SYSTEM BACKGROUND OF THE INVENTION The present invention relates to an axial flow hydraulic turbine electric generator system, which incorporates an axial flow hydraulic turbine having a stationary guide blade and a rotary impeller arranged coaxial with each other in the direction of water flow. In general, hydraulic power systems have different specifications such as different heads, flow rates, etc., which depend upon their installation locations. Therefore, hydraulic turbines employed therein are manufactured one by one in accordance with conditions that differ between installation locations. However, designing and manufacturing hydraulic turbines of different specifications for different installation locations is inevitably inefficient, requires a high cost for constructing plants for the manufacture of the turbines, and is not economically viable. in order to improve the economical viability, it may be considered to enhance the manufacturing efficiency by mass-producing such hydraulic turbines. However, it is difficult to efficiently mass-producing the hydraulic turbines of different specifications. BRIEF SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an axial flow hydraulic turbine electric generator system, which uses mass-produced hydraulic turbines, i.e. hydraulic turbines produced at a high efficiency, and which can be installed in various locations. According to one aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow, and having respective rotary impellers; and an electric generator arranged parallel with the plurality of unit axial flow hydraulic turbines in the direction of water flow, and driven by shaft outputs of the plurality of unit axial flow hydraulic turbines. In the system, the rotary impellers of adjacent ones of the unit axial flow hydraulic turbines may rotate in opposite directions. The system may further comprise a gear mechanism for obtaining a one-way shaft output from the shaft outputs of the adjacent ones of the unit axial flow hydraulic turbines. The system may further comprise a stationary guide blade provided at an outlet side of a flow passage formed in that one of the unit axial flow hydraulic turbines, which is situated furthest downstream. In the system, the electric generator may be provided outside the flow passage, and the shaft outputs of the unit axial flow hydraulic turbines may be transmitted to the electric generator using gears with intersecting axes. According to another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged parallel to each other in a flow passage in a direction perpendicular to a direction of water flow, and having respective rotary impellers; and an electric generator driven by shaft outputs of the plurality of unit axial flow hydraulic turbines. According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of axial flow hydraulic turbines arranged parallel to each other in a flow passage in a direction perpendicular to a direction of water flow, each of the plurality of axial flow hydraulic turbines including a plurality of unit axial flow hydraulic turbines arranged coaxial therewith and having respective rotary impellers; and an electric generator driven by shaft outputs of the plurality of unit axial flow hydraulic turbines. The system may further comprise at least one of a pulley transmission mechanism and a gear mechanism for transmitting the shaft outputs of the plurality of unit axial flow hydraulic turbines at a predetermined speed. In the system, the rotary impellers of the plurality of unit axial flow hydraulic turbines may have same blade shape, and a blade attachment angle may be set for each of the unit axial flow hydraulic turbines. According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow/ and having respective rotary impellers; and transmission means for combining shaft outputs of the plurality of unit axial flow hydraulic turbines into at least one output, and transmitting the at least one output to an electric generator. In the system, the transmission means may include transmission units provided on circumferential portions' of the rotary impellers of the unit axial flow hydraulic turbines, and the transmission units may be interlocked with each other. In the system, the transmission means may include: a driving wheel and a driven wheel concentric therewith and provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines; an intermediate wheel having first and second transmitting wheels and provided between each pair of adjacent ones of the unit axial flow hydraulic turbines; and means for interlocking the first transmitting wheel with that one of the adjacent unit axial flow hydraulic turbines, which is close to the first transmitting wheel, and also interlocking the second transmitting wheel with the other of the adjacent unit axial flow hydraulic turbines. In the system, the transmission means may include concentric transmitting wheels provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines, and the transmitting wheels of each pair of adjacent ones of the unit axial flow hydraulic turbines may be interlocked with each other by means of one of a belt and a chain. In the system, the transmission means may include a transmitting gear concentrically provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines, and the gears of adjacent ones of the unit axial flow hydraulic turbines may be interlocked with each other. The system may further comprise gear transmission means for interlocking shafts of each pair of adjacent ones of the unit axial flow hydraulic turbines with each other. In the system, the gear transmission means may include first and second bevel gears provided on the shaft of each of the unit axial flow hydraulic turbines, and transmission shafts for interlocking the first bevel gear with that one of adjacent ones of the unit axial flow hydraulic turbines, which is close to the first bevel gear, and interlocking the second bevel gear with the other of the adjacent ones of the unit axial flow hydraulic turbines. According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a unit axial flow hydraulic turbine having a rotary impeller; and an electric generator located outside a flow passage and driven by a shaft output of the unit axial flow hydraulic turbine, wherein the unit axial flow hydraulic turbine is arranged such that a shaft thereof is parallel to a direction of water flow, and the electric generator is arranged such that a shaft thereof is parallel to the shaft of the unit axial flow hydraulic turbine. The system may further comprise one of a belt and a chain for transmitting a shaft output of the unit axial flow hydraulic turbine to the electric generator. The system may further comprise: a first gear mechanism for converting a shaft output of the unit axial flow hydraulic turbine into a shaft output exerted in a direction perpendicular to the shaft of the unit axial flow hydraulic turbine; and a second gear mechanism for converting the converted shaft output into an output exerted in a direction parallel to a shaft of the electric generator to transmit the obtained output to the electric generator. According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a unit axial flow hydraulic turbine having a stationary guide blade and a rotary impeller; and an electric generator located outside a flow passage and driven by a shaft output of the unit axial flow hydraulic turbine, wherein the stationary guide blade constitutes one unit together with an external cylinder and an internal cylinder, to which the stationary guide blade is attached, the unit and the rotary impeller is capable of being taken out of the flow passage. In the system, part of members that constitute the unit axial flow hydraulic turbine may be formed integral, as one body, with part of members that constitute the electric generator, whereby unit axial flow hydraulic turbine and the electric generator are reinforced. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a first embodiment of the invention; FIG. 2 is an enlarged view illustrating a connecting section between unit axial flow hydraulic turbines and an electric generator appearing in FIG. 1; FIG. 3 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a second embodiment of the invention; FIG. 4 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a third embodiment of the invention; FIG. 5 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a fourth embodiment of the invention; FIG. 6 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a fifth embodiment of the invention; FIG. 7 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention; FIG. 8 is a schematic view illustrating the apparatus of FIG. 7 when viewed from the downstream side of the flow; FIG. 9 is a modification of the apparatus shown in FIG. 8; FIG. 10 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a seventh embodiment of the invention; FIG. 11 is a schematic view illustrating the apparatus of FIG. 10 when viewed from the downstream side of the flow; FIG. 12 is a view showing a modification of the apparatus of FIG. 11; FIG. 13 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eighth embodiment of the invention; FIG. 14 is a schematic view illustrating the apparatus of FIG. 13 when viewed from the downstream side of the flow; FIG. 15 is a view showing a modification of the apparatus of FIG. 14; FIG. 16 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a ninth embodiment of the invention; FIG. 17 is a view showing a modification of the apparatus of FIG. 16; FIG. 18 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a tenth embodiment of the invention; FIG. 19 is a sectional view illustrating that portion of the apparatus of FIG. 18 when viewed from downstream, which is located in the vicinity of a belt and perpendicular to the shaft of the electric generator; FIG. 20 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eleventh embodiment of the invention; FIG. 21 is a sectional view illustrating that portion of the apparatus of FIG. 20 when viewed from downstream, which is located in the vicinity of a power transmission shaft and perpendicular to the shaft of the electric generator; and FIG. 22 is an exploded view of an axial flow hydraulic turbine electric generator system according to a twelfth embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION The embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a first embodiment of the invention. In FIG. 1, reference numeral 101 denotes a hydraulic turbine casing, which contains first and second unit axial flow hydraulic turbines 102 and 103 arranged coaxial. The first and second unit axial flow hydraulic turbines 102 and 103 are supported by an upstream-side stationary guide blade 105, which is provided upstream of an impeller 104 incorporated in the first unit axial flow hydraulic turbine 102, and is fixed to the inner surface of the turbine casing 101. The turbines 102 and 103 are also supported by a downstream-side stationary guide blade 107, which is provided downstream of an impeller 106 incorporated in the second unit axial flow hydraulic turbine 103, and is fixed to the inner surface of the turbine casing 101. Further, an intermediate stationary guide blade 108 is fixed on the casing 101 and interposed between the impeller 104 of the first unit axial flow hydraulic turbine 102 and the impeller 106 of the second unit axial flow hydraulic turbine 103. A generator casing 109 is connected to the upstream end of the turbine casing 101. An electric generator 111 is contained in the casing 109 and supported by an electric generator bracket 110. The electric generator 111 is arranged coaxial with the first and second unit axial flow hydraulic turbines 102 and 103, and connected thereto via a reversal gear 112 and an accelerating gear 113, which will be described later. The second unit axial flow hydraulic turbine 103 is arranged to rotate in a direction opposite to that of the first unit axial flow hydraulic turbine 102, so as to absorb the revolving component of the water flow at the outlet of the upstream-side first unit axial flow hydraulic turbine 102, and increase the efficiency of the turbines. The second unit axial flow hydraulic turbine 103 has its rotary shaft 103a inserted through the first unit axial flow hydraulic turbine 102. FIG. 2 is an enlarged view illustrating a connecting section between the first and second unit axial flow hydraulic turbines 102 and 103 and the electric generator 111. As is shown in FIG. 2, a first sun gear 114 is provided on the rotary shaft 102a of the first unit axial flow hydraulic turbine 102, and a gear 115 located around the circumference of the sun gear 114 is engaged therewith. On the other hand, a second sun gear 116 is provided on the rotary shaft 103a of the second unit axial flow hydraulic turbine 103, and an intermediate gear 117 located around the circumference of the second sun gear 116 is engaged therewith. Furthermore, a gear 118 that rotates together with the gear 115 is engaged with the intermediate gear 117. A gear 119 that rotates together with the intermediate gear 117 is engaged with a gear 120 provided on the main shaft Ilia. Accordingly, when the impellers 104 and 106 of the first and second unit axial flow hydraulic turbines 102 and 103 are rotated by water flowing in the turbine casing 101, the torque of the impeller 106, and the torque of the impeller 104 reversely rotated by the first sun gear 114, the gear 115, etc. are transmitted to the intermediate gear 117. The torque of the gear 117 is transmitted to the generator main shaft Ilia via the gears 119 and 120, whereby electric power is generated. Thus, in the embodiment, a plurality of unit axial flow hydraulic turbines each including a stationary guide blade and a rotary impeller are connected in series, and the respective shaft outputs are transmitted to a single electric generator to thereby generate power. This means that various combinations of unit axial flow hydraulic turbines enable their use in electric generator systems with different specifications such as different heads, different flow rates, etc., even if the turbines have been mass-produced on the basis of the same design, i.e. produced at a high efficiency. As a result, cost effectiveness of the system is improved. Moreover, in the case of an electric generator system with specifications that cause a revolving component at the outlet of its upstream-side hydraulic turbine, the efficiency of its hydraulic turbines can be enhanced by rotating upstream-side and downstream-side hydraulic turbines in opposite directions as aforementioned, to thereby cause the downstream-side turbine to absorb the revolving component. Also, the provision of a stationary guide blade at the outlet side of the flow passage of a unit turbine situated furthest downstream enables reduction of vibration due to a revolving component at the outlet of the turbine. As a result, the turbine can be operated quietly. In addition, appropriate setting of the gear ratio of the gears that constitute the reversal gear 112 enables establishment of an appropriate relationship in rotational speed between the first and second unit axial flow hydraulic turbines 102 and 103. In this embodiment, the gear mechanism may be replaced with a wrapping connector unit. In the embodiments described below, similar structural elements to those in the first embodiment are denoted by corresponding reference numerals, and no detailed description will be given thereof. In the first embodiment, the generator casing 9 is provided upstream of the axial flow hydraulic turbines, and the generator 111 is located in the casing. This may be modified as shown in FIG. 3, where an elbow 121 is attached upstream of the hydraulic turbine casing 101, and the generator main shaft 111a of the electric generator 111 provided outside the flow passage is inserted in the elbow 121 and connected to the axial flow hydraulic turbine. This structure does not limit the size of the electric generator and can reduce the resistance of flowing water, as compared with the structure shown in FIG. 1. FIG. 4 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a third embodiment of the invention. In this embodiment, the first and second unit axial flow hydraulic turbines 122 and 123 are arranged to rotate in the same direction. In this structure, the shaft output of the first and second unit axial flow hydraulic turbines 122 and 123 can be transmitted as an optimal torque for driving the electric generator 111. Unlike the first embodiment, the third embodiment is suitable for a case where no revolving component remains in the flow at the outlet of the upstream-side unit axial flow hydraulic turbine. FIG. 5 shows the structure of an axial flow hydraulic turbine electric generator system according to a fourth embodiment of the invention. This generator system is applicable to a case where the head is larger than in the case of FIG. 1. In the axial flow hydraulic turbine electric generator system of FIG. 5, two axial flow hydraulic turbines as shown in FIG. 1 are connected in series along the axis of the flow passage by means of an intermediate shaft 125, for driving the single electric generator 111. FIG. 6 shows the structure of an axial flow hydraulic turbine electric generator system according to a fifth embodiment of the invention. This generator is adapted to utilize a high flow rate. In this embodiment, a plurality of axial flow hydraulic turbines as shown in FIG. 1, which are designed to correspond to a predetermined head and flow rate, are arranged in a single passage parallel to each other along the flow of water. The shaft outputs of these turbines are transmitted to an intermediate shaft 127 via gears 126 with intersecting axes, and also to the main shaft Ilia of the electric generator 111 connected to the shaft 127. Thus, the generator 111 is driven. As described above, the structure of FIG. 6 employs a plurality of axial flow hydraulic turbines as shown in FIG. 1 and arranged parallel to each other. Instead, a plurality of axial flow hydraulic turbines as shown in FIG. 5 may be arranged parallel to each other. This structure can be used in electric generator equipment with such specifications as a large head and a high flow rate. In each of the above-described embodiments, each impeller is designed to correspond to a predetermined head and flow rate, and each blade is attached thereto at a predetermined angle. The hydraulic performance of each unit axial flow hydraulic turbine can be finely adjusted by changing the attachment angle of each blade, thereby changing their water-level-difference/ flow-rate specifications to those suitable for any installation location. FIG. 7 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention. FIG. 8 is a view illustrating the apparatus of FIG. 7 when viewed from the downstream side of the flow passage. A hydraulic turbine casing 202 is provided across a pipe line 201. The casing 202 contains first to third unit axial flow hydraulic turbines 203A, 203B and 203C that are arranged parallel to each other along the flow of water. The first to third unit axial flow hydraulic turbines 203A, 203B and 203C have the same configuration and size, and each include an inlet conduit pipe 204, an outlet conduit pipe 205, and a rotary impeller 206 interposed therebetween. A plurality of stationary guide blades 207 are provided on the inlet conduit pipe 204 for guiding water that flows into the rotary impeller 206. Water flowing in the pipe line 201 is guided by each stationary guide blade 207 to the rotary impeller 206 to thereby rotate the impeller 206. A driving pulley 208 and a driven pulley 209 are concentrically provided on the circumference of an outer race 206a incorporated in the rotary impeller 206 of each of the axial flow hydraulic turbines 203A, 203B and 203C. Further, intermediate wheels 210 and 211 having first transmission wheels 210a and 21la and second transmission wheels 210b and 211b, respectively, are provided between the unit axial flow hydraulic turbines 203A and 203B and between the unit axial flow hydraulic turbines 203B and 203C, respectively. A belt 212a is wound on the driving pulley 208 provided on the outer race 206a of the rotary impeller 206 of the first unit axial flow hydraulic turbine 203A, and wound on the first transmission wheel 210a of the intermediate wheel 210 situated between the first and second unit axial flow hydraulic turbines 203A and 203B. A belt 212b is wound on the second transmission wheel 210b of the intermediate wheel 210, and wound on the driven pulley 209 of the second unit axial flow hydraulic turbine 203B. Similarly, a belt 212c is wound on the driving pulley 208 of the second unit axial flow hydraulic turbine 203B, and wound on the second transmission wheel 21la of the second intermediate wheel 211. A belt 212d is wound on the second transmission wheel 2l1b of the second intermediate wheel 211, and wound on the driven pulley 209 of the third unit axial flow hydraulic turbine 203C. Further, a belt 212e wound on the driving pulley 208 of the third unit axial flow hydraulic turbine 203C is wound on a pulley 214 provided on a generator shaft 213. In this structure, the shaft output of the first unit axial flow hydraulic turbine 203A is transmitted, by means of the belts 212a and 212b, to the driven pulley 209 of the second third unit axial flow hydraulic turbine 203B adjacent to the turbine 203A, and is combined with the shaft output of the second unit axial flow hydraulic turbine 203B. The combined shaft output of the first and second unit axial flow hydraulic turbines 203A and 204B is combined with that of the third unit axial flow hydraulic turbine 203C via the belts 212c and 212d. The shaft output of the third unit axial flow hydraulic turbine 203C, which is the sum of the shaft output of itself and that of the first and second unit axial flow hydraulic turbines 203A and 203B, is transmitted to the generator shaft 213 to thereby drive an electric generator (not shown). Thus, the shaft outputs of adjacent unit axial flow hydraulic turbines are sequentially combined with each other. As a result, the shaft outputs of a plurality of unit axial flow hydraulic turbines are combined into one output, which is used to rotate the electric generator for generating power. Although, in the above embodiment, three unit axial flow hydraulic turbines are arranged parallel to each other, much more unit axial flow hydraulic turbines may be arranged adjacent to each other as shown in FIG. 9. In the case of FIG. 9, seven unit axial flow hydraulic turbines 203A, 203B, ... 203G are arranged adjacent to each other such that six unit axial flow hydraulic turbines are arranged around the unit axial flow hydraulic turbine 203A. The first and second unit axial flow hydraulic turbines 203A and 203B are interlocked with each other by means of belts 212a and 212b in a similar manner to the case of FIG. 8, while the second and third unit axial flow hydraulic turbines 203B and 203C are interlocked by means of belts 212c and 212d. Similarly, adjacent unit axial flow hydraulic turbines are interlocked with each other. The shaft output of the seventh unit axial flow hydraulic turbine 203G is transmitted to the generator shaft 213 by means of the pulley 214. In the sixth embodiment, the shaft outputs of a plurality of unit axial flow hydraulic turbines are combined into one output, which is transmitted to a single electric generator. This may be modified such that the shaft outputs of unit axial flow hydraulic turbines are combined into a plurality of groups, which are transmitted to a plurality of electric generators. In the embodiments described below, similar structural elements to those in the sixth embodiment are denoted by corresponding reference numerals, and no detailed description will be given thereof. i FIGS. 10 and 11 show the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention, and correspond to FIGS. 7 and 8, respectively. In FIGS. 10 and 11, a transmission pulley 215 is provided on the circumference of an outer race 206a incorporated in the rotary impeller 206 of each of the axial flow hydraulic turbines 203A, 203B and 203C. Further, pairs of intermediate wheels 216 each having a transmission wheel 216a are provided between the unit axial flow hydraulic turbines 203A and 203B and between the unit axial flow hydraulic turbines 203B and 203C, and between the third unit axial flow hydraulic turbine 203C and the pulley 214, as is shown in FIG. 11. A single belt 217 is wound on the transmission pulley 215 provided on the outer race 206a of the rotary impeller 206 of each of the first to third unit axial flow hydraulic turbines 203A, 203B and 203C, and also wound on the pulley 214 provided on the generator shaft 213. Those portions of the belt 217, which are situated between each pair of adjacent ones of the turbines, are urged toward each other by the transmission wheels 216a of a corresponding pair of the intermediate wheels 216. Thus, the shaft outputs of the unit axial flow hydraulic turbines 2.03A to 203C are transmitted to the generator shaft 213 via the single belt 217 and the pulley 214. In other words, also in this case, the shaft outputs of the unit axial flow hydraulic turbines are combined into one output, which is transmitted to the single generator shaft. FIG. 12 shows a modification of the structure shown in FIG. 11. In this modification, seven unit axial flow hydraulic turbines are arranged adjacent to each other. Like the case shown in FIGS. 10 and 11, a single belt 217 is wound on pulleys 215 provided on the seven unit axial flow hydraulic turbines and also wound on a pulley 214 provided on a generator shaft 213. Accordingly, the shaft outputs of the seven unit axial flow hydraulic turbines 203A to 203G are combined by the single belt 217 into one output, which is transmitted to the generator shaft 213. Thus, the structure shown in FIG. 12 has the same advantage as that of, for example, FIG. 10. Although, in each of the above-described embodiments, pulleys and a belt are used as transmission means, chain wheels and a chain may be used in place of them. FIGS. 13 and 14 show the structure of an axial flow hydraulic turbine electric generator system according to an eighth embodiment of the invention, and correspond to FIGS. 7 and 8, respectively. A gear 218 is provided on the outer race 206a of the rotary impeller 206 incorporated in each of unit axial flow hydraulic turbines 203A, 203B and 203C. The gear 218 of the first unit axial flow hydraulic turbine 203A is engaged with the gear 218 of the second unit axial flow hydraulic turbine 203B with a first intermediate gear 219a. Similarly, the gear 218 of the second unit axial flow hydraulic turbine 203B is engaged with the gear 218 of the second unit axial flow hydraulic turbine 203C with a second intermediate gear 219b. In other words, the gears 218 of the adjacent unit axial flow hydraulic turbines 203A and 203B, or of the adjacent unit axial flow hydraulic turbines 203B and 203C, are interlocked with each other by means of the intermediate gear 219a or 219b. The gear 218 of the third unit axial flow hydraulic turbine 203C is engaged with a driven gear 220 provided at the generator shaft 213. Also in this case, the shaft outputs of the unit axial flow hydraulic turbines 203A to 203C are combined into one output, which is transmitted to the generator shaft 213 via the driven gear 220. Thus, this embodiment has the same advantage as that of each of the above-described embodiments. FIG. 15 shows a modification of the structure shown in FIG. 14. In this modification, seven unit axial flow hydraulic turbines 203A to 203G are arranged adjacent to each other. Also in this case, the gears 218 of adjacent unit axial flow hydraulic turbines are engaged with each other by means of intermediate gears 219a, 219b, ... As a result, the shaft outputs of the seven unit axial flow hydraulic turbines are combined into one output, which is transmitted to the generator shaft 213. FIG. 16 shows the structure of an axial flow hydraulic turbine electric generator system according to a ninth embodiment of the invention. First and second bevel gears 222a and 222b are provided on the shaft 221 of each of the unit axial flow hydraulic turbines 203A, 203B and 203C arranged parallel to each other along the flow of water. Further, a transmission shaft 223a is provided between the first and second unit axial flow hydraulic turbines 203A and 203B such that it connects these turbines. Similarly, a transmission shaft 223b is provided between the second and third unit axial flow hydraulic turbines 203B and 203C such that it connects these turbines. The transmission shaft 223a has a bevel gear 224a provided at an end thereof and engaged with the first bevel gear 222a that is provided on the transmission shaft 221 of the first unit axial flow hydraulic turbine 203A. The transmission shaft 223a also has a bevel gear 224b provided at the other end thereof and engaged with the first bevel gear 222a that is provided on the transmission shaft 221 of the second unit axial flow hydraulic turbine 203B. The second bevel gear 222b provided on the shaft 221 of the second unit axial flow hydraulic turbine 203B is engaged with a bevel gear 225a provided at an end of the transmission shaft 223b. A bevel gear 225b provided at the other end of the transmission shaft 223b is engaged with the second bevel gear 222b provided on the shaft 221 of the third unit axial flow hydraulic turbine 203C. Furthermore, the first bevel gear 222a provided on the shaft 221 of the third unit axial flow hydraulic turbine 203C is engaged with a bevel gear 226 provided on the generator shaft 213. In this structure, the shaft output of the first unit axial flow hydraulic turbine 203A is combined with that of the second unit axial flow hydraulic turbine 203B by means of the bevel gears 222a and 224a, the transmission shaft 223a and the bevel gears 224b and 222a. The combined shaft output of the first and second unit axial flow hydraulic turbines 203A and 204B is combined with that of the third unit axial flow hydraulic turbine 203C by means of the bevel gear 222b of the second unit axial flow hydraulic turbine 203B, the bevel gear 225a of the transmission shaft 223b, the transmission shaft 223b, the bevel gear 225b of the shaft 223b, and the bevel gear 222b engaged with the bevel gear 225b. The combined shaft output of the first to third unit axial flow hydraulic turbines 203A to 203C is transmitted to the generator shaft 213 by means of the bevel gear 222a of the third unit axial flow hydraulic turbine 203C and the bevel gear 226 engaged therewith. Thus, the shaft outputs of the adjacent unit axial flow hydraulic turbines 203A to 203C is combined into one output, which is used to drive the electric generator. FIG. 17 shows a modification of the structure shown in FIG. 16. In this modification, seven unit axial flow hydraulic turbines 203A to 203G are included in the electric generator. Also in this case, a similar bevel gear transmission mechanism to that employed in FIG. 16 is used to combine the shaft outputs of the seven unit axial flow hydraulic turbines 203A to 203G. Therefore, this modification can provide the same advantage as that of the above-described embodiments. In the sixth to-ninth embodiments, three or seven unit axial flow hydraulic turbines are included in an electric generator. However, it is a matter of course that the number of unit axial flow hydraulic turbines included in the generator is not limited to three or seven. Moreover, a plurality of driving pulleys 208 and driven pulleys 209 may be included in each unit axial flow hydraulic turbine. In a case where an electric generator is located outside the flow passage of each axial flow hydraulic turbine, the shaft output of each unit axial flow hydraulic turbine is transmitted to the generator that is located outside the flow passage and has a rotary shaft coaxial with the rotary shaft of each turbine, via the rotary shaft of each turbine inserted through a bending tube located upstream or downstream of a corresponding impeller. In this case, each turbine shaft is inserted through a corresponding rotary impeller, and bearings are provided upstream and downstream of each rotary impeller and support a corresponding turbine shaft. Each turbine and the generator are different structures. When using a bending tube to install an electric generator outside the flow passage, a complicated tube is necessary for converting the flow of water, output from axial flow hydraulic turbines and bent by the bending tube, into a straight flow. For such a complicated tube, a large installment area is required. In addition, flow bending inevitably increases a loss of hydraulic force. Also, since the turbine shaft extends through each rotary impeller, it is necessary, when exchanging rotary impellers, to disassemble the bearings in order to pull the turbine shaft out of each rotary impeller. It is also necessary, when detaching each rotary impeller from inside the flow passage, to disassemble front and rear conduits of each axial flow hydraulic turbine. Moreover, since a bending tube is interposed between the turbines and the generator, they must be separated. To install them, complicated work is necessary for adjusting the relationship in the positions of their axes. Embodiments for solving these problems will now be described. FIG. 18 shows the structure of an axial flow hydraulic turbine electric generator system according to a tenth embodiment of the invention. Between an upstream conduit 324 and a downstream conduit 325, there are provided a first unit axial flow hydraulic turbine 300A that includes an inlet turbine external cylinder 301, an inlet stationary wing (stationary guide blade) 307, an inlet turbine internal cylinder 332, a main turbine external cylinder 302, a turbine shaft 309, a rotary impeller 308 and an outlet stationary wing 310; and a second unit axial flow hydraulic turbine 300B that includes an inlet turbine external cylinder 303, an inlet stationary wing (stationary guide blade) 313, an inlet turbine internal cylinder 334, a main turbine external cylinder 304, a turbine shaft 315, a rotary impeller 308, and an outlet stationary wing 316. The first and second unit axial flow hydraulic turbines 300A and 300B are arranged in series along the flow of water, and the turbine shafts 309 and 315 are connected, with an intermediate shaft 311 interposed therebetween. The shaft outputs of these unit axial flow hydraulic turbines are combined into one output, which is transmitted, to a generator pulley 320 connected to an end of a generator shaft 319 parallel to the turbine shafts 309 and 315, via a turbine pulley 317 located at the downstream end of the turbine shaft 315 and a belt (or chain) 322, thereby driving an electric generator 323. At this time, the relative positional relationship between the turbine shaft 315 and the generator shaft 319 is maintained by a power transmission case 305. This structure enables handling of the unit axial flow hydraulic turbines 300A and 300B and the electric generator 323 as one integral body, when installing the axial flow hydraulic turbine electric generator system of the invention between the upstream conduit 324 and the downstream conduit 325. FIG. 19 is a sectional view illustrating that portion of the apparatus of FIG. 18 when viewed from downstream, which is located in the vicinity of a belt and perpendicular to the generator shaft. The belt 322 transmits, through a belt inserting hole 321 to the generator pulley 320 located outside the flow passage, the shaft output of the turbine shaft 317 located in a turbine outlet internal cylinder 336 that is located in the flow passage. As a result, the generator is driven. In this embodiment, the electric generator can be installed without bending a conduit for containing therein axial flow hydraulic turbines, by arranging the rotary shaft of the generator parallel to the turbine shaft, not coaxial with it. This enables installment of the axial flow hydraulic turbine electric generator system in a rather small area. Further, a straight flow passage enables the loss of hydraulic force to be reduced. Moreover, in this embodiment, the pulley provided on the downstream end of the rotary shaft of the rotary impeller of the downstream-side hydraulic turbine is connected to the pulley provided on an end of the generator shaft by a belt or a chain inserted in a pipe that is located in the flow passage between the inner and outer cylinders of the downstream-side hydraulic turbine. This enables transmission, to the electric generator, of the shaft outputs of the rotary impellers of the hydraulic turbines, without significantly narrowing the flow passage between the internal and external cylinders of the downstream-side turbine. FIG. 20 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eleventh embodiment of the invention. Between an upstream conduit 324 and a downstream conduit 325, there are provided a first unit axial flow hydraulic turbine 300A that includes an inlet turbine external cylinder 301, an inlet stationary wing 307, an inlet turbine internal cylinder 332, a main turbine external cylinder 302, a turbine shaft 309, a rotary impeller 308 and an outlet stationary wing 310; and a second unit axial flow hydraulic turbine 300B that includes an inlet turbine external cylinder 303, an inlet stationary wing (stationary guide blade) 313, an inlet turbine internal cylinder 334, a main turbine external cylinder 304, a turbine shaft 315, a rotary impeller 308, and an outlet stationary wing 316. The first and second unit axial flow hydraulic turbines 300A and 300B are arranged in series along the flow of water, and the turbine shafts 309 and 315 are connected, with an intermediate shaft 311 interposed therebetween. The shaft outputs of these unit axial flow hydraulic turbines are combined into one output, which is transmitted from a turbine gear 327 provided at the downstream end of the turbine shaft 315, to a generator gear 331 connected to an end of a generator shaft 319 parallel to the turbine shaft 315, via a turbine gear 328 having a rotary shaft perpendicular to the turbine shaft 315, a power transmission shaft 329 and a generator gear 330, thereby driving an electric generator 323. FIG. 21 is a sectional view illustrating that portion of the apparatus of FIG. 20 when viewed from downstream, which is located in the vicinity of a power transmission shaft and perpendicular to the shaft of the electric generator. The relative positional relationship between the turbine shaft 315 and the generator shaft 319 is maintained by a power transmission case 326. This structure enables handling of the unit axial flow hydraulic turbines 300A and 300B and the electric generator 323 as one integral body, when installing the axial flow hydraulic turbine electric generator system of the invention between the upstream conduit 324 and the downstream conduit 325. Also in this embodiment, the electric generator can be installed without bending a conduit for containing therein axial flow hydraulic turbines, by arranging the rotary shaft of the generator parallel to the turbine shaft, not coaxial with it. This enables installment of the axial flow hydraulic turbine electric generator system in a rather small area. Further, a straight flow passage enables the loss of hydraulic force to be reduced. Moreover, in this embodiment, the rotary shaft of the rotary impeller of the downstream-side hydraulic turbine is connected to the orthogonal gear driving unit provided on an end of the generator shaft by means of a gear shaft perpendicular to the rotary shaft of the rotary impeller and inserted in a pipe that is located in the flow passage between the inner and outer cylinders of the downstream-side hydraulic turbine. This enables transmission of the shaft outputs of the rotary impellers of the hydraulic turbines to the electric generator, without significantly narrowing the flow passage between the internal and external cylinders of the downstream-side turbine. In addition, in the tenth and eleventh embodiments, part of the members constituting the hydraulic turbines is formed integral as one body with part of members constituting the generator so as to reinforce the structure. This enables handling, as one integral body, of the unit axial flow hydraulic turbine electric generator system that includes the axial flow hydraulic turbines and the electric generator, when installing it in the conduit. As a result, the accurate positional relationship between the turbine shaft and the generator shaft can be maintained stably, and generation of vibrations of the shafts, for example, can be suppressed during the operation of the system. Furthermore, since the distance between the turbine shaft and the generator shaft is kept short, the required installment area of the generator system that includes the axial flow hydraulic turbines and the electric generator can be made smaller than the case where the generator and the hydraulic turbines are formed as separate members. FIG. 22 shows an exploded state of the axial flow hydraulic turbine electric generator system of FIG. 18. As shown in FIG. 22, the system is disassembled when, for example, the rotary impeller 308 or 314 is life-expired and exchanged for a new one, or is shifted from inside the flow passage to outside it. When taking, out of the flow passage, the rotary impeller 308 of the unit axial flow hydraulic turbine 300A, the unit constituting the inlet turbine external cylinder 301, the inlet turbine internal cylinder 332, the inlet stationary wing (stationary guide blade) 307, and an inlet cowl 306 is divided into two portions in a circumferential direction before taking out the impeller. Subsequently, the unit is detached from the axial flow hydraulic turbine electric generator system to secure a space through which the rotary impeller 308 from the flow passage. After the rotary impeller 308 is detached from the turbine shaft 309, it is taken out of the flow passage. When taking, out of the flow passage, the rotary impeller 314 of the unit axial flow hydraulic turbine 300B, the unit constituting the inlet turbine external cylinder 303, the inlet turbine internal cylinder 334, and the inlet stationary wing (stationary guide blade) 313 is divided into two portions in a circumferential direction before taking out the impeller. Subsequently, the unit and then the intermediate internal cylinder 312 and the intermediate shaft 311 are detached from the axial flow hydraulic turbine electric generator system, to secure a space through which the rotary impeller 314 from the flow passage. After the rotary impeller 314 is detached from the turbine shaft 315, it is taken out of the flow passage. In this embodiment, a single bearing, which supports the shaft of each axial flow hydraulic turbine, is provided upstream or downstream of a corresponding rotary impeller, and each internal cylinder having no bearing for supporting a turbine shaft, which is located upstream or downstream of the rotary impeller, is formed integral with a corresponding external cylinder as one body by means of a corresponding stationary guide blade. This structure enables radial detachment of the flow passage having the stationary guide blade and located downstream or upstream of each rotary impeller, without disassembling an upstream portion or a downstream portion of the flow passage located near the stationary guide blade, thereby securing, upstream or downstream of each rotary impeller, a space for taking each rotary impeller out of the flow passage, detaching each rotary impeller from a corresponding turbine shaft without disassembling a corresponding bearing, and taking each rotary impeller out of the flow passage without detaching conduits located upstream and downstream of a corresponding axial flow hydraulic turbine. As described in detail, in the axial flow hydraulic turbine electric generator systems of the present invention, a plurality of unit axial flow hydraulic turbines of the same specification, e.g. the same flow rate, the same head, etc., are combined so as to deal with various types of specifications. As a result, hydraulic turbines manufactured by mass production can be used in the system, and hence the system can be manufactured at a high efficiency. This enables installment of such a system even in a place where it could not be installed so far in view of economic viability. Further, the shaft outputs of units axial flow hydraulic turbines arranged parallel to each other can be combined into one output by a relatively simple mechanism. Furthermore, a straight flow passage can be provided in the axial flow hydraulic turbine electric generator system without using a bending tube. As a result, the flow passage can be simplified, the required installment area of the system is reduced, and the system is free from loss of hydraulic force due to such a bending tube. Also, each rotary impeller incorporated in the system can be exchanged for a new one without disassembling the upstream and downstream conduits. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. For example, in each embodiment, each electric generator may be instead located at an opposite side with respect to the corresponding unit axial flow hydraulic turbines, symmetrically about a plane perpendicular to a direction of water flow. We Claim : 1. An axial flow hydraulic turbine electric generator system, comprising : a fluid conduit pipe (301 to 304) having a connecting portion for connecting with an upstream conduit (324) and connecting portion for connection with a downstream conduit (325); a unit axial flow hydraulic turbine (300A, 300B) arranged in the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel to a direction of fluid flow and having a rotary impeller (308, 314); and an electric generator (323) arranged outside the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel to the fluid conduit pipe (301 to 304) and driven by a shaft output of the unit axial flow hydraulic turbine (300A, 300B). 2. The system as claimed in claim 1, wherein the shaft of the generator (323) is driven by the shaft of the turbine via a belt (322) or a chain (322). 3. The system as claimed in claim 1, including : a first gear mechanism (326, 328) for converting the shaft output of the unit axial flow hydraulic turbine into a converted shaft (329) output exerted in a direction perpendicular to the shaft of the unit axial flow hydraulic turbine ; and a second gear mechanism (330, 331) for converting the converted shaft (329) output into an output exerted in a direction parallel to a shaft of the electric generator (323) to transmit the obtained output to the electric generator (323). 4. The system is claimed in claim 1, wherein ; the unit axial flow hydraulic turbine (300A, 300B has a stationary guide blade (307, 313) and a rotary impeller (308, 314), and the stationary guide blade (307, 313) constitutes one unit together with an external cylinder (301, 303) and an internal cylinder (332, 334), to which the stationary guide blade (307, 313) is attached, the unit and the rotary impeller (308, 314) is capable of being taken out of the flow passage. 5. The system as claimed in claim 1, wherein part of the unit axial flow hydraulic turbine (300A, 300B) is integrally formed with the electric generator (323), whereby the unit axial flow hydraulic turbine (300A, 300B) and the electric generator (323) are reinforced. 6. The system as claimed in claim 1, wherein the system includes a plurality of unit axial flow hydraulic turbines (300A and 300B) arranged in series in the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel to a direction of fluid flow. 7. An axial flow hydraulic turbine electric generator system, substantially as herein before described with reference to the accompanying drawings.

Full Text

TITLE OF THE INVENTION
AXIAL FLOW HYDRAULIC TURBINE ELECTRIC GENERATOR SYSTEM BACKGROUND OF THE INVENTION
The present invention relates to an axial flow hydraulic turbine electric generator system, which incorporates an axial flow hydraulic turbine having a stationary guide blade and a rotary impeller arranged coaxial with each other in the direction of water flow.
In general, hydraulic power systems have different specifications such as different heads, flow rates, etc., which depend upon their installation locations. Therefore, hydraulic turbines employed therein are manufactured one by one in accordance with conditions that differ between installation locations.
However, designing and manufacturing hydraulic turbines of different specifications for different installation locations is inevitably inefficient, requires a high cost for constructing plants for the manufacture of the turbines, and is not economically viable. in order to improve the economical viability, it may be considered to enhance the manufacturing efficiency by mass-producing such hydraulic turbines. However, it is difficult to efficiently mass-producing the hydraulic turbines of different specifications. BRIEF SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an axial flow hydraulic turbine
electric generator system, which uses mass-produced hydraulic turbines, i.e. hydraulic turbines produced at a high efficiency, and which can be installed in various locations.
According to one aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow, and having respective rotary impellers; and an electric generator arranged parallel with the plurality of unit axial flow hydraulic turbines in the direction of water flow, and driven by shaft outputs of the plurality of unit axial flow hydraulic turbines.
In the system, the rotary impellers of adjacent ones of the unit axial flow hydraulic turbines may rotate in opposite directions.
The system may further comprise a gear mechanism for obtaining a one-way shaft output from the shaft outputs of the adjacent ones of the unit axial flow hydraulic turbines.
The system may further comprise a stationary guide blade provided at an outlet side of a flow passage formed in that one of the unit axial flow hydraulic turbines, which is situated furthest downstream.
In the system, the electric generator may be provided outside the flow passage, and the shaft
outputs of the unit axial flow hydraulic turbines may be transmitted to the electric generator using gears with intersecting axes.
According to another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged parallel to each other in a flow passage in a direction perpendicular to a direction of water flow, and having respective rotary impellers; and an electric generator driven by shaft outputs of the plurality of unit axial flow hydraulic turbines.
According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of axial flow hydraulic turbines arranged parallel to each other in a flow passage in a direction perpendicular to a direction of water flow, each of the plurality of axial flow hydraulic turbines including a plurality of unit axial flow hydraulic turbines arranged coaxial therewith and having respective rotary impellers; and an electric generator driven by shaft outputs of the plurality of unit axial flow hydraulic turbines.
The system may further comprise at least one of a pulley transmission mechanism and a gear mechanism for transmitting the shaft outputs of the plurality of unit

axial flow hydraulic turbines at a predetermined speed.
In the system, the rotary impellers of the plurality of unit axial flow hydraulic turbines may have same blade shape, and a blade attachment angle may be set for each of the unit axial flow hydraulic turbines.
According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a plurality of unit axial flow hydraulic turbines arranged coaxial with each other in a flow passage along a direction of water flow/ and having respective rotary impellers; and transmission means for combining shaft outputs of the plurality of unit axial flow hydraulic turbines into at least one output, and transmitting the at least one output to an electric generator.
In the system, the transmission means may include transmission units provided on circumferential portions' of the rotary impellers of the unit axial flow hydraulic turbines, and the transmission units may be interlocked with each other.
In the system, the transmission means may include: a driving wheel and a driven wheel concentric therewith and provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines; an intermediate wheel having first and second transmitting
wheels and provided between each pair of adjacent ones of the unit axial flow hydraulic turbines; and means for interlocking the first transmitting wheel with that one of the adjacent unit axial flow hydraulic turbines, which is close to the first transmitting wheel, and also interlocking the second transmitting wheel with the other of the adjacent unit axial flow hydraulic turbines.
In the system, the transmission means may include concentric transmitting wheels provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines, and the transmitting wheels of each pair of adjacent ones of the unit axial flow hydraulic turbines may be interlocked with each other by means of one of a belt and a chain.
In the system, the transmission means may include a transmitting gear concentrically provided on an outer race of the rotary impeller of each of the unit axial flow hydraulic turbines, and the gears of adjacent ones of the unit axial flow hydraulic turbines may be interlocked with each other.
The system may further comprise gear transmission means for interlocking shafts of each pair of adjacent ones of the unit axial flow hydraulic turbines with each other.
In the system, the gear transmission means may include first and second bevel gears provided on
the shaft of each of the unit axial flow hydraulic turbines, and transmission shafts for interlocking the first bevel gear with that one of adjacent ones of the unit axial flow hydraulic turbines, which is close to the first bevel gear, and interlocking the second bevel gear with the other of the adjacent ones of the unit axial flow hydraulic turbines.
According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a unit axial flow hydraulic turbine having a rotary impeller; and an electric generator located outside a flow passage and driven by a shaft output of the unit axial flow hydraulic turbine, wherein the unit axial flow hydraulic turbine is arranged such that a shaft thereof is parallel to a direction of water flow, and the electric generator is arranged such that a shaft thereof is parallel to the shaft of the unit axial flow hydraulic turbine.
The system may further comprise one of a belt and a chain for transmitting a shaft output of the unit axial flow hydraulic turbine to the electric generator.
The system may further comprise: a first gear mechanism for converting a shaft output of the unit axial flow hydraulic turbine into a shaft output exerted in a direction perpendicular to the shaft of the unit axial flow hydraulic turbine; and a second

gear mechanism for converting the converted shaft output into an output exerted in a direction parallel to a shaft of the electric generator to transmit the obtained output to the electric generator.
According to still another aspect of the present invention, there is provided an axial flow hydraulic turbine electric generator system comprising: a unit axial flow hydraulic turbine having a stationary guide blade and a rotary impeller; and an electric generator located outside a flow passage and driven by a shaft output of the unit axial flow hydraulic turbine, wherein the stationary guide blade constitutes one unit together with an external cylinder and an internal cylinder, to which the stationary guide blade is attached, the unit and the rotary impeller is capable of being taken out of the flow passage.
In the system, part of members that constitute the unit axial flow hydraulic turbine may be formed integral, as one body, with part of members that constitute the electric generator, whereby unit axial flow hydraulic turbine and the electric generator are reinforced.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a first embodiment of the invention;
FIG. 2 is an enlarged view illustrating a connecting section between unit axial flow hydraulic turbines and an electric generator appearing in FIG. 1;
FIG. 3 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a second embodiment of the invention;
FIG. 4 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a third embodiment of the invention;
FIG. 5 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a fourth embodiment of the invention;
FIG. 6 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a fifth embodiment of the invention;
FIG. 7 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention;
FIG. 8 is a schematic view illustrating the apparatus of FIG. 7 when viewed from the downstream side of the flow;
FIG. 9 is a modification of the apparatus shown in
FIG. 8;
FIG. 10 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a seventh embodiment of the invention;
FIG. 11 is a schematic view illustrating the apparatus of FIG. 10 when viewed from the downstream side of the flow;
FIG. 12 is a view showing a modification of the apparatus of FIG. 11;
FIG. 13 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eighth embodiment of the invention;
FIG. 14 is a schematic view illustrating the apparatus of FIG. 13 when viewed from the downstream side of the flow;
FIG. 15 is a view showing a modification of the apparatus of FIG. 14;
FIG. 16 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a ninth embodiment of the invention;
FIG. 17 is a view showing a modification of the apparatus of FIG. 16;
FIG. 18 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic
turbine electric generator system according to a tenth embodiment of the invention;
FIG. 19 is a sectional view illustrating that portion of the apparatus of FIG. 18 when viewed from downstream, which is located in the vicinity of a belt and perpendicular to the shaft of the electric generator;
FIG. 20 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eleventh embodiment of the invention;
FIG. 21 is a sectional view illustrating that portion of the apparatus of FIG. 20 when viewed from downstream, which is located in the vicinity of a power transmission shaft and perpendicular to the shaft of the electric generator; and
FIG. 22 is an exploded view of an axial flow hydraulic turbine electric generator system according to a twelfth embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The embodiments of the invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a first embodiment of the invention.
In FIG. 1, reference numeral 101 denotes a hydraulic turbine casing, which contains first and second unit axial flow hydraulic turbines 102 and 103 arranged coaxial. The first and second unit axial flow hydraulic turbines 102 and 103 are supported by an upstream-side stationary guide blade 105, which is provided upstream of an impeller 104 incorporated in the first unit axial flow hydraulic turbine 102, and is fixed to the inner surface of the turbine casing 101. The turbines 102 and 103 are also supported by a downstream-side stationary guide blade 107, which is provided downstream of an impeller 106 incorporated in the second unit axial flow hydraulic turbine 103, and is fixed to the inner surface of the turbine casing 101. Further, an intermediate stationary guide blade 108 is fixed on the casing 101 and interposed between the impeller 104 of the first unit axial flow hydraulic turbine 102 and the impeller 106 of the second unit axial flow hydraulic turbine 103.
A generator casing 109 is connected to the upstream end of the turbine casing 101. An electric generator 111 is contained in the casing 109 and supported by an electric generator bracket 110. The electric generator 111 is arranged coaxial with the first and second unit axial flow hydraulic turbines 102 and 103, and connected thereto via a reversal gear 112 and an accelerating gear 113, which will be
described later.
The second unit axial flow hydraulic turbine 103 is arranged to rotate in a direction opposite to that of the first unit axial flow hydraulic turbine 102, so as to absorb the revolving component of the water flow at the outlet of the upstream-side first unit axial flow hydraulic turbine 102, and increase the efficiency of the turbines. The second unit axial flow hydraulic turbine 103 has its rotary shaft 103a inserted through the first unit axial flow hydraulic turbine 102.
FIG. 2 is an enlarged view illustrating a connecting section between the first and second unit axial flow hydraulic turbines 102 and 103 and the electric generator 111.
As is shown in FIG. 2, a first sun gear 114 is provided on the rotary shaft 102a of the first unit axial flow hydraulic turbine 102, and a gear 115 located around the circumference of the sun gear 114 is engaged therewith. On the other hand, a second sun gear 116 is provided on the rotary shaft 103a of the second unit axial flow hydraulic turbine 103, and an intermediate gear 117 located around the circumference of the second sun gear 116 is engaged therewith. Furthermore, a gear 118 that rotates together with the gear 115 is engaged with the intermediate gear 117. A gear 119 that rotates together with the intermediate gear 117 is engaged with a gear 120 provided on the
main shaft Ilia.
Accordingly, when the impellers 104 and 106 of the first and second unit axial flow hydraulic turbines 102 and 103 are rotated by water flowing in the turbine casing 101, the torque of the impeller 106, and the torque of the impeller 104 reversely rotated by the first sun gear 114, the gear 115, etc. are transmitted to the intermediate gear 117. The torque of the gear 117 is transmitted to the generator main shaft Ilia via the gears 119 and 120, whereby electric power is generated.
Thus, in the embodiment, a plurality of unit axial flow hydraulic turbines each including a stationary guide blade and a rotary impeller are connected in series, and the respective shaft outputs are transmitted to a single electric generator to thereby generate power. This means that various combinations of unit axial flow hydraulic turbines enable their use in electric generator systems with different specifications such as different heads, different flow rates, etc., even if the turbines have been mass-produced on the basis of the same design, i.e. produced at a high efficiency. As a result, cost effectiveness of the system is improved. Moreover, in the case of an electric generator system with specifications that cause a revolving component at the outlet of its upstream-side hydraulic turbine, the efficiency of
its hydraulic turbines can be enhanced by rotating upstream-side and downstream-side hydraulic turbines in opposite directions as aforementioned, to thereby cause the downstream-side turbine to absorb the revolving component. Also, the provision of a stationary guide blade at the outlet side of the flow passage of a unit turbine situated furthest downstream enables reduction of vibration due to a revolving component at the outlet of the turbine. As a result, the turbine can be operated quietly. In addition, appropriate setting of the gear ratio of the gears that constitute the reversal gear 112 enables establishment of an appropriate relationship in rotational speed between the first and second unit axial flow hydraulic turbines 102 and 103. In this embodiment, the gear mechanism may be replaced with a wrapping connector unit.
In the embodiments described below, similar structural elements to those in the first embodiment are denoted by corresponding reference numerals, and no detailed description will be given thereof.
In the first embodiment, the generator casing 9 is provided upstream of the axial flow hydraulic turbines, and the generator 111 is located in the casing. This may be modified as shown in FIG. 3, where an elbow 121 is attached upstream of the hydraulic turbine casing 101, and the generator main shaft 111a of the electric
generator 111 provided outside the flow passage is inserted in the elbow 121 and connected to the axial flow hydraulic turbine.
This structure does not limit the size of the electric generator and can reduce the resistance of flowing water, as compared with the structure shown in FIG. 1.
FIG. 4 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a third embodiment of the invention.
In this embodiment, the first and second unit axial flow hydraulic turbines 122 and 123 are arranged to rotate in the same direction. In this structure, the shaft output of the first and second unit axial flow hydraulic turbines 122 and 123 can be transmitted as an optimal torque for driving the electric generator 111. Unlike the first embodiment, the third embodiment is suitable for a case where no revolving component remains in the flow at the outlet of the upstream-side unit axial flow hydraulic turbine.
FIG. 5 shows the structure of an axial flow hydraulic turbine electric generator system according to a fourth embodiment of the invention. This generator system is applicable to a case where the
head is larger than in the case of FIG. 1.
In the axial flow hydraulic turbine electric generator system of FIG. 5, two axial flow hydraulic turbines as shown in FIG. 1 are connected in series along the axis of the flow passage by means of an intermediate shaft 125, for driving the single electric generator 111.
FIG. 6 shows the structure of an axial flow hydraulic turbine electric generator system according to a fifth embodiment of the invention. This generator is adapted to utilize a high flow rate.
In this embodiment, a plurality of axial flow hydraulic turbines as shown in FIG. 1, which are designed to correspond to a predetermined head and flow rate, are arranged in a single passage parallel to each other along the flow of water. The shaft outputs of these turbines are transmitted to an intermediate shaft 127 via gears 126 with intersecting axes, and also to the main shaft Ilia of the electric generator 111 connected to the shaft 127. Thus, the generator 111 is driven.
As described above, the structure of FIG. 6 employs a plurality of axial flow hydraulic turbines as shown in FIG. 1 and arranged parallel to each other. Instead, a plurality of axial flow hydraulic turbines as shown in FIG. 5 may be arranged parallel to each
other. This structure can be used in electric generator equipment with such specifications as a large head and a high flow rate.
In each of the above-described embodiments, each impeller is designed to correspond to a predetermined head and flow rate, and each blade is attached thereto at a predetermined angle. The hydraulic performance of each unit axial flow hydraulic turbine can be finely adjusted by changing the attachment angle of each blade, thereby changing their water-level-difference/ flow-rate specifications to those suitable for any installation location.
FIG. 7 is a longitudinal sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention. FIG. 8 is a view illustrating the apparatus of FIG. 7 when viewed from the downstream side of the flow passage.
A hydraulic turbine casing 202 is provided across a pipe line 201. The casing 202 contains first to third unit axial flow hydraulic turbines 203A, 203B and 203C that are arranged parallel to each other along the flow of water.
The first to third unit axial flow hydraulic turbines 203A, 203B and 203C have the same configuration and size, and each include an inlet conduit pipe
204, an outlet conduit pipe 205, and a rotary impeller 206 interposed therebetween. A plurality of stationary guide blades 207 are provided on the inlet conduit pipe 204 for guiding water that flows into the rotary impeller 206. Water flowing in the pipe line 201 is guided by each stationary guide blade 207 to the rotary impeller 206 to thereby rotate the impeller 206.
A driving pulley 208 and a driven pulley 209 are concentrically provided on the circumference of an outer race 206a incorporated in the rotary impeller 206 of each of the axial flow hydraulic turbines 203A, 203B and 203C. Further, intermediate wheels 210 and 211 having first transmission wheels 210a and 21la and second transmission wheels 210b and 211b, respectively, are provided between the unit axial flow hydraulic turbines 203A and 203B and between the unit axial flow hydraulic turbines 203B and 203C, respectively.
A belt 212a is wound on the driving pulley 208 provided on the outer race 206a of the rotary impeller 206 of the first unit axial flow hydraulic turbine 203A, and wound on the first transmission wheel 210a of the intermediate wheel 210 situated between the first and second unit axial flow hydraulic turbines 203A and 203B. A belt 212b is wound on the second transmission wheel 210b of the intermediate wheel 210, and wound on the driven pulley 209 of the second unit axial flow hydraulic turbine 203B. Similarly, a belt 212c is
wound on the driving pulley 208 of the second unit axial flow hydraulic turbine 203B, and wound on the second transmission wheel 21la of the second intermediate wheel 211. A belt 212d is wound on the second transmission wheel 2l1b of the second intermediate wheel 211, and wound on the driven pulley 209 of the third unit axial flow hydraulic turbine 203C.
Further, a belt 212e wound on the driving pulley 208 of the third unit axial flow hydraulic turbine 203C is wound on a pulley 214 provided on a generator shaft 213.
In this structure, the shaft output of the first unit axial flow hydraulic turbine 203A is transmitted, by means of the belts 212a and 212b, to the driven pulley 209 of the second third unit axial flow hydraulic turbine 203B adjacent to the turbine 203A, and is combined with the shaft output of the second unit axial flow hydraulic turbine 203B. The combined shaft output of the first and second unit axial flow hydraulic turbines 203A and 204B is combined with that of the third unit axial flow hydraulic turbine 203C via the belts 212c and 212d. The shaft output of the third unit axial flow hydraulic turbine 203C, which is the sum of the shaft output of itself and that of the first and second unit axial flow hydraulic turbines 203A and 203B, is transmitted to the generator shaft 213 to thereby drive an electric generator (not shown).
Thus, the shaft outputs of adjacent unit axial flow hydraulic turbines are sequentially combined with each other. As a result, the shaft outputs of a plurality of unit axial flow hydraulic turbines are combined into one output, which is used to rotate the electric generator for generating power.
Although, in the above embodiment, three unit axial flow hydraulic turbines are arranged parallel to each other, much more unit axial flow hydraulic turbines may be arranged adjacent to each other as shown in FIG. 9.
In the case of FIG. 9, seven unit axial flow hydraulic turbines 203A, 203B, ... 203G are arranged adjacent to each other such that six unit axial flow hydraulic turbines are arranged around the unit axial flow hydraulic turbine 203A. The first and second unit axial flow hydraulic turbines 203A and 203B are interlocked with each other by means of belts 212a and 212b in a similar manner to the case of FIG. 8, while the second and third unit axial flow hydraulic turbines 203B and 203C are interlocked by means of belts 212c and 212d. Similarly, adjacent unit axial flow hydraulic turbines are interlocked with each other. The shaft output of the seventh unit axial flow hydraulic turbine 203G is transmitted to the generator shaft 213 by means of the pulley 214.
In the sixth embodiment, the shaft outputs of
a plurality of unit axial flow hydraulic turbines are combined into one output, which is transmitted to a single electric generator. This may be modified such that the shaft outputs of unit axial flow hydraulic turbines are combined into a plurality of groups, which are transmitted to a plurality of electric generators.
In the embodiments described below, similar structural elements to those in the sixth embodiment are denoted by corresponding reference numerals, and no detailed description will be given thereof.
i
FIGS. 10 and 11 show the structure of an axial flow hydraulic turbine electric generator system according to a sixth embodiment of the invention, and correspond to FIGS. 7 and 8, respectively.
In FIGS. 10 and 11, a transmission pulley 215 is provided on the circumference of an outer race 206a incorporated in the rotary impeller 206 of each of the axial flow hydraulic turbines 203A, 203B and 203C. Further, pairs of intermediate wheels 216 each having a transmission wheel 216a are provided between the unit axial flow hydraulic turbines 203A and 203B and between the unit axial flow hydraulic turbines 203B and 203C, and between the third unit axial flow hydraulic turbine 203C and the pulley 214, as is shown in FIG. 11.
A single belt 217 is wound on the transmission pulley 215 provided on the outer race 206a of the
rotary impeller 206 of each of the first to third unit axial flow hydraulic turbines 203A, 203B and 203C, and also wound on the pulley 214 provided on the generator shaft 213. Those portions of the belt 217, which are situated between each pair of adjacent ones of the turbines, are urged toward each other by the transmission wheels 216a of a corresponding pair of the intermediate wheels 216.
Thus, the shaft outputs of the unit axial flow hydraulic turbines 2.03A to 203C are transmitted to the generator shaft 213 via the single belt 217 and the pulley 214. In other words, also in this case, the shaft outputs of the unit axial flow hydraulic turbines are combined into one output, which is transmitted to the single generator shaft.
FIG. 12 shows a modification of the structure shown in FIG. 11. In this modification, seven unit axial flow hydraulic turbines are arranged adjacent to each other. Like the case shown in FIGS. 10 and 11, a single belt 217 is wound on pulleys 215 provided on the seven unit axial flow hydraulic turbines and also wound on a pulley 214 provided on a generator shaft 213. Accordingly, the shaft outputs of the seven unit axial flow hydraulic turbines 203A to 203G are combined by the single belt 217 into one output, which is transmitted to the generator shaft 213. Thus, the structure shown in FIG. 12 has the same advantage as
that of, for example, FIG. 10.
Although, in each of the above-described embodiments, pulleys and a belt are used as transmission means, chain wheels and a chain may be used in place of them.
FIGS. 13 and 14 show the structure of an axial flow hydraulic turbine electric generator system according to an eighth embodiment of the invention, and correspond to FIGS. 7 and 8, respectively.
A gear 218 is provided on the outer race 206a of the rotary impeller 206 incorporated in each of unit axial flow hydraulic turbines 203A, 203B and 203C. The gear 218 of the first unit axial flow hydraulic turbine 203A is engaged with the gear 218 of the second unit axial flow hydraulic turbine 203B with a first intermediate gear 219a. Similarly, the gear 218 of the second unit axial flow hydraulic turbine 203B is engaged with the gear 218 of the second unit axial flow hydraulic turbine 203C with a second intermediate gear 219b. In other words, the gears 218 of the adjacent unit axial flow hydraulic turbines 203A and 203B, or of the adjacent unit axial flow hydraulic turbines 203B and 203C, are interlocked with each other by means of the intermediate gear 219a or 219b. The gear 218 of the third unit axial flow hydraulic turbine 203C is engaged with a driven gear 220 provided at the
generator shaft 213.
Also in this case, the shaft outputs of the unit axial flow hydraulic turbines 203A to 203C are combined into one output, which is transmitted to the generator shaft 213 via the driven gear 220. Thus, this embodiment has the same advantage as that of each of the above-described embodiments.
FIG. 15 shows a modification of the structure shown in FIG. 14. In this modification, seven unit axial flow hydraulic turbines 203A to 203G are arranged adjacent to each other. Also in this case, the gears 218 of adjacent unit axial flow hydraulic turbines are engaged with each other by means of intermediate gears 219a, 219b, ... As a result, the shaft outputs of the seven unit axial flow hydraulic turbines are combined into one output, which is transmitted to the generator shaft 213.
FIG. 16 shows the structure of an axial flow hydraulic turbine electric generator system according to a ninth embodiment of the invention.
First and second bevel gears 222a and 222b are provided on the shaft 221 of each of the unit axial flow hydraulic turbines 203A, 203B and 203C arranged
parallel to each other along the flow of water.
Further, a transmission shaft 223a is provided between the first and second unit axial flow hydraulic turbines

203A and 203B such that it connects these turbines. Similarly, a transmission shaft 223b is provided between the second and third unit axial flow hydraulic turbines 203B and 203C such that it connects these turbines. The transmission shaft 223a has a bevel gear 224a provided at an end thereof and engaged with the first bevel gear 222a that is provided on the transmission shaft 221 of the first unit axial flow hydraulic turbine 203A. The transmission shaft 223a also has a bevel gear 224b provided at the other end thereof and engaged with the first bevel gear 222a that is provided on the transmission shaft 221 of the second unit axial flow hydraulic turbine 203B.
The second bevel gear 222b provided on the shaft 221 of the second unit axial flow hydraulic turbine 203B is engaged with a bevel gear 225a provided at an end of the transmission shaft 223b. A bevel gear 225b provided at the other end of the transmission shaft 223b is engaged with the second bevel gear 222b provided on the shaft 221 of the third unit axial flow hydraulic turbine 203C. Furthermore, the first bevel gear 222a provided on the shaft 221 of the third unit axial flow hydraulic turbine 203C is engaged with a bevel gear 226 provided on the generator shaft 213.
In this structure, the shaft output of the first unit axial flow hydraulic turbine 203A is combined with that of the second unit axial flow hydraulic turbine
203B by means of the bevel gears 222a and 224a, the transmission shaft 223a and the bevel gears 224b and 222a. The combined shaft output of the first and second unit axial flow hydraulic turbines 203A and 204B is combined with that of the third unit axial flow hydraulic turbine 203C by means of the bevel gear 222b of the second unit axial flow hydraulic turbine 203B, the bevel gear 225a of the transmission shaft 223b, the transmission shaft 223b, the bevel gear 225b of the shaft 223b, and the bevel gear 222b engaged with the bevel gear 225b. The combined shaft output of the first to third unit axial flow hydraulic turbines 203A to 203C is transmitted to the generator shaft 213 by means of the bevel gear 222a of the third unit axial flow hydraulic turbine 203C and the bevel gear 226 engaged therewith.
Thus, the shaft outputs of the adjacent unit axial flow hydraulic turbines 203A to 203C is combined into one output, which is used to drive the electric generator.
FIG. 17 shows a modification of the structure shown in FIG. 16. In this modification, seven unit axial flow hydraulic turbines 203A to 203G are included in the electric generator. Also in this case, a similar bevel gear transmission mechanism to that employed in FIG. 16 is used to combine the shaft outputs of the seven unit axial flow hydraulic turbines
203A to 203G. Therefore, this modification can provide the same advantage as that of the above-described embodiments.
In the sixth to-ninth embodiments, three or seven unit axial flow hydraulic turbines are included in an electric generator. However, it is a matter of course that the number of unit axial flow hydraulic turbines included in the generator is not limited to three or seven. Moreover, a plurality of driving pulleys 208 and driven pulleys 209 may be included in each unit axial flow hydraulic turbine.
In a case where an electric generator is located outside the flow passage of each axial flow hydraulic turbine, the shaft output of each unit axial flow hydraulic turbine is transmitted to the generator that is located outside the flow passage and has a rotary shaft coaxial with the rotary shaft of each turbine, via the rotary shaft of each turbine inserted through a bending tube located upstream or downstream of a corresponding impeller. In this case, each turbine shaft is inserted through a corresponding rotary impeller, and bearings are provided upstream and downstream of each rotary impeller and support a corresponding turbine shaft. Each turbine and the generator are different structures.
When using a bending tube to install an electric generator outside the flow passage, a complicated tube
is necessary for converting the flow of water, output from axial flow hydraulic turbines and bent by the bending tube, into a straight flow. For such a complicated tube, a large installment area is required. In addition, flow bending inevitably increases a loss of hydraulic force. Also, since the turbine shaft extends through each rotary impeller, it is necessary, when exchanging rotary impellers, to disassemble the bearings in order to pull the turbine shaft out of each rotary impeller. It is also necessary, when detaching each rotary impeller from inside the flow passage, to disassemble front and rear conduits of each axial flow hydraulic turbine. Moreover, since a bending tube is interposed between the turbines and the generator, they must be separated. To install them, complicated work is necessary for adjusting the relationship in the positions of their axes. Embodiments for solving these problems will now be described.
FIG. 18 shows the structure of an axial flow hydraulic turbine electric generator system according to a tenth embodiment of the invention.
Between an upstream conduit 324 and a downstream conduit 325, there are provided a first unit axial flow hydraulic turbine 300A that includes an inlet turbine external cylinder 301, an inlet stationary wing (stationary guide blade) 307, an inlet turbine internal
cylinder 332, a main turbine external cylinder 302, a turbine shaft 309, a rotary impeller 308 and an outlet stationary wing 310; and a second unit axial flow hydraulic turbine 300B that includes an inlet turbine external cylinder 303, an inlet stationary wing (stationary guide blade) 313, an inlet turbine internal cylinder 334, a main turbine external cylinder 304, a turbine shaft 315, a rotary impeller 308, and an outlet stationary wing 316. The first and second unit axial flow hydraulic turbines 300A and 300B are arranged in series along the flow of water, and the turbine shafts 309 and 315 are connected, with an intermediate shaft 311 interposed therebetween. The shaft outputs of these unit axial flow hydraulic turbines are combined into one output, which is transmitted, to a generator pulley 320 connected to an end of a generator shaft 319 parallel to the turbine shafts 309 and 315, via a turbine pulley 317 located at the downstream end of the turbine shaft 315 and a belt (or chain) 322, thereby driving an electric generator 323. At this time, the relative positional relationship between the turbine shaft 315 and the generator shaft 319 is maintained by a power transmission case 305. This structure enables handling of the unit axial flow hydraulic turbines 300A and 300B and the electric generator 323 as one integral body, when installing the axial flow hydraulic turbine electric generator system of the invention between the
upstream conduit 324 and the downstream conduit 325.
FIG. 19 is a sectional view illustrating that portion of the apparatus of FIG. 18 when viewed from downstream, which is located in the vicinity of a belt and perpendicular to the generator shaft. The belt 322 transmits, through a belt inserting hole 321 to the generator pulley 320 located outside the flow passage, the shaft output of the turbine shaft 317 located in a turbine outlet internal cylinder 336 that is located in the flow passage. As a result, the generator is driven.
In this embodiment, the electric generator can be installed without bending a conduit for containing therein axial flow hydraulic turbines, by arranging the rotary shaft of the generator parallel to the turbine shaft, not coaxial with it. This enables installment of the axial flow hydraulic turbine electric generator system in a rather small area. Further, a straight flow passage enables the loss of hydraulic force to be reduced.
Moreover, in this embodiment, the pulley provided on the downstream end of the rotary shaft of the rotary impeller of the downstream-side hydraulic turbine is connected to the pulley provided on an end of the generator shaft by a belt or a chain inserted in a pipe that is located in the flow passage between the inner and outer cylinders of the downstream-side hydraulic
turbine. This enables transmission, to the electric generator, of the shaft outputs of the rotary impellers of the hydraulic turbines, without significantly narrowing the flow passage between the internal and external cylinders of the downstream-side turbine.
FIG. 20 is a sectional view illustrating the structure of an axial flow hydraulic turbine electric generator system according to an eleventh embodiment of the invention.
Between an upstream conduit 324 and a downstream conduit 325, there are provided a first unit axial flow hydraulic turbine 300A that includes an inlet turbine external cylinder 301, an inlet stationary wing 307, an inlet turbine internal cylinder 332, a main turbine external cylinder 302, a turbine shaft 309, a rotary impeller 308 and an outlet stationary wing 310; and a second unit axial flow hydraulic turbine 300B that includes an inlet turbine external cylinder 303, an inlet stationary wing (stationary guide blade) 313, an inlet turbine internal cylinder 334, a main turbine external cylinder 304, a turbine shaft 315, a rotary impeller 308, and an outlet stationary wing 316. The first and second unit axial flow hydraulic turbines 300A and 300B are arranged in series along the flow of water, and the turbine shafts 309 and 315 are connected, with an intermediate shaft 311 interposed
therebetween. The shaft outputs of these unit axial flow hydraulic turbines are combined into one output, which is transmitted from a turbine gear 327 provided at the downstream end of the turbine shaft 315, to a generator gear 331 connected to an end of a generator shaft 319 parallel to the turbine shaft 315, via a turbine gear 328 having a rotary shaft perpendicular to the turbine shaft 315, a power transmission shaft 329 and a generator gear 330, thereby driving an electric generator 323.
FIG. 21 is a sectional view illustrating that portion of the apparatus of FIG. 20 when viewed from downstream, which is located in the vicinity of a power transmission shaft and perpendicular to the shaft of the electric generator. The relative positional relationship between the turbine shaft 315 and the generator shaft 319 is maintained by a power transmission case 326. This structure enables handling of the unit axial flow hydraulic turbines 300A and 300B and the electric generator 323 as one integral body, when installing the axial flow hydraulic turbine electric generator system of the invention between the upstream conduit 324 and the downstream conduit 325.
Also in this embodiment, the electric generator can be installed without bending a conduit for containing therein axial flow hydraulic turbines, by arranging the rotary shaft of the generator parallel to
the turbine shaft, not coaxial with it. This enables installment of the axial flow hydraulic turbine electric generator system in a rather small area. Further, a straight flow passage enables the loss of hydraulic force to be reduced.
Moreover, in this embodiment, the rotary shaft of the rotary impeller of the downstream-side hydraulic turbine is connected to the orthogonal gear driving unit provided on an end of the generator shaft by means of a gear shaft perpendicular to the rotary shaft of the rotary impeller and inserted in a pipe that is located in the flow passage between the inner and outer cylinders of the downstream-side hydraulic turbine. This enables transmission of the shaft outputs of the rotary impellers of the hydraulic turbines to the electric generator, without significantly narrowing the flow passage between the internal and external cylinders of the downstream-side turbine.
In addition, in the tenth and eleventh embodiments, part of the members constituting the hydraulic turbines is formed integral as one body with part of members constituting the generator so as to reinforce the structure. This enables handling, as one integral body, of the unit axial flow hydraulic turbine electric generator system that includes the axial flow hydraulic turbines and the electric generator, when installing it in the conduit. As a result, the
accurate positional relationship between the turbine shaft and the generator shaft can be maintained stably, and generation of vibrations of the shafts, for example, can be suppressed during the operation of the system. Furthermore, since the distance between the turbine shaft and the generator shaft is kept short, the required installment area of the generator system that includes the axial flow hydraulic turbines and the electric generator can be made smaller than the case where the generator and the hydraulic turbines are formed as separate members.
FIG. 22 shows an exploded state of the axial flow hydraulic turbine electric generator system of FIG. 18. As shown in FIG. 22, the system is disassembled when, for example, the rotary impeller 308 or 314 is life-expired and exchanged for a new one, or is shifted from inside the flow passage to outside it.
When taking, out of the flow passage, the rotary impeller 308 of the unit axial flow hydraulic turbine 300A, the unit constituting the inlet turbine external cylinder 301, the inlet turbine internal cylinder 332, the inlet stationary wing (stationary guide blade) 307, and an inlet cowl 306 is divided into two portions in a circumferential direction before taking out the impeller. Subsequently, the unit is detached from the axial flow hydraulic turbine electric generator system
to secure a space through which the rotary impeller 308 from the flow passage. After the rotary impeller 308 is detached from the turbine shaft 309, it is taken out of the flow passage.
When taking, out of the flow passage, the rotary impeller 314 of the unit axial flow hydraulic turbine 300B, the unit constituting the inlet turbine external cylinder 303, the inlet turbine internal cylinder 334, and the inlet stationary wing (stationary guide blade) 313 is divided into two portions in a circumferential direction before taking out the impeller. Subsequently, the unit and then the intermediate internal cylinder 312 and the intermediate shaft 311 are detached from the axial flow hydraulic turbine electric generator system, to secure a space through which the rotary impeller 314 from the flow passage. After the rotary impeller 314 is detached from the turbine shaft 315, it is taken out of the flow passage.
In this embodiment, a single bearing, which supports the shaft of each axial flow hydraulic turbine, is provided upstream or downstream of a corresponding rotary impeller, and each internal cylinder having no bearing for supporting a turbine shaft, which is located upstream or downstream of the rotary impeller, is formed integral with a corresponding external cylinder as one body by means of a corresponding stationary guide blade. This structure
enables radial detachment of the flow passage having the stationary guide blade and located downstream or upstream of each rotary impeller, without disassembling an upstream portion or a downstream portion of the flow passage located near the stationary guide blade, thereby securing, upstream or downstream of each rotary impeller, a space for taking each rotary impeller out of the flow passage, detaching each rotary impeller from a corresponding turbine shaft without disassembling a corresponding bearing, and taking each rotary impeller out of the flow passage without detaching conduits located upstream and downstream of a corresponding axial flow hydraulic turbine.
As described in detail, in the axial flow hydraulic turbine electric generator systems of the present invention, a plurality of unit axial flow hydraulic turbines of the same specification, e.g. the same flow rate, the same head, etc., are combined so as to deal with various types of specifications. As a result, hydraulic turbines manufactured by mass production can be used in the system, and hence the system can be manufactured at a high efficiency. This enables installment of such a system even in a place where it could not be installed so far in view of economic viability. Further, the shaft outputs of units axial flow hydraulic turbines arranged parallel to each other can be combined into one output by a
relatively simple mechanism. Furthermore, a straight flow passage can be provided in the axial flow hydraulic turbine electric generator system without using a bending tube. As a result, the flow passage can be simplified, the required installment area of the system is reduced, and the system is free from loss of hydraulic force due to such a bending tube. Also, each rotary impeller incorporated in the system can be exchanged for a new one without disassembling the upstream and downstream conduits.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. For example, in each embodiment, each electric generator may be instead located at an opposite side with respect to the corresponding unit axial flow hydraulic turbines, symmetrically about a plane perpendicular to a direction of water flow.

We Claim :
1. An axial flow hydraulic turbine electric generator system, comprising :
a fluid conduit pipe (301 to 304) having a connecting portion for connecting with an upstream conduit (324) and connecting portion for connection with a downstream conduit (325);
a unit axial flow hydraulic turbine (300A, 300B) arranged in the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel to a direction of fluid flow and having a rotary impeller (308, 314); and
an electric generator (323) arranged outside the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel to the fluid conduit pipe (301 to 304) and driven by a shaft output of the unit axial flow hydraulic turbine (300A, 300B).
2. The system as claimed in claim 1, wherein the shaft of the generator
(323) is driven by the shaft of the turbine via a belt (322) or a chain
(322).
3. The system as claimed in claim 1, including :
a first gear mechanism (326, 328) for converting the shaft output of the unit axial flow hydraulic turbine into a converted shaft (329) output exerted in a direction perpendicular to the shaft of the unit axial flow hydraulic turbine ; and
a second gear mechanism (330, 331) for converting the converted shaft (329) output into an output exerted in a direction parallel to a shaft of the electric generator (323) to transmit the obtained output to the electric generator (323).
4. The system is claimed in claim 1, wherein ;
the unit axial flow hydraulic turbine (300A, 300B has a stationary guide blade (307, 313) and a rotary impeller (308, 314), and
the stationary guide blade (307, 313) constitutes one unit together with an external cylinder (301, 303) and an internal cylinder (332, 334), to which the stationary guide blade (307, 313) is attached, the unit and the rotary impeller (308, 314) is capable of being taken out of the flow passage.
5. The system as claimed in claim 1, wherein part of the unit axial flow
hydraulic turbine (300A, 300B) is integrally formed with the electric
generator (323), whereby the unit axial flow hydraulic turbine (300A,
300B) and the electric generator (323) are reinforced.
6. The system as claimed in claim 1, wherein the system includes a plurality
of unit axial flow hydraulic turbines (300A and 300B) arranged in series
in the fluid conduit pipe (301 to 304) such that a shaft thereof is parallel
to a direction of fluid flow.
7. An axial flow hydraulic turbine electric generator system, substantially as
herein before described with reference to the accompanying drawings.

Documents:

740-del-2000-abstract.pdf

740-del-2000-claims.pdf

740-del-2000-correspondence-others.pdf

740-del-2000-correspondence-po.pdf

740-del-2000-description (complete).pdf

740-del-2000-drawings.pdf

740-del-2000-form-1.pdf

740-del-2000-form-19.pdf

740-del-2000-form-2.pdf

740-DEL-2000-Form-3.pdf

740-del-2000-form-5.pdf

740-del-2000-form-6.pdf

740-del-2000-pa.pdf

740-del-2000-petition-138.pdf

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Patent Number

216778

Indian Patent Application Number

740/DEL/2000

PG Journal Number

13/2008

Publication Date

31-Mar-2008

Grant Date

19-Mar-2008

Date of Filing

16-Aug-2000

Name of Patentee

TOSHIBA ENGINEERING CORPORATION,

Applicant Address

66-2, HORIKAWA-CHO, SAIWAI-KU, KAWASAKI-SHI, JAPAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	HIROMARA INABA	13-301, TERAODAIDANCHI, 8-1, TERAODAI 2-CHOME, TAMA-KU, KAWASAKI-SHI, KANAGAWA-KEN, JAPAN.
2	HIROTAKA AKAMATSU	206, 13-2, SAKAEMACHIDOORI 2-CHOME, TSURUMI-KU, YOKOHAMA-SHI, KANAGAWA-KEN, JAPAN.
3	ICHIRO YAMAGATA	10-22, NAKAHARA 2-CHOME, ISOGO-KU, YOKOHAMA-SHI, KANAGAWA-KEN, JAPAN.
4	KEI HONMA	31-15, KITATERAO 6-CHOME, TSURUMI-KU, YOKOHAMA-SHI, KANAGAWA-KEN, JAPAN.
5	KOICHIRO SHIMIZU	21-1-103, NAMIKI 1-CHOME, KANAZAWA-KU, YOKOHAMA-SHI, KANGAWA-KEN, JAPAN.
6	AKIRA SHINOHARA	5-17-204, UMEDA 6-CHOME, ADACHI-KU, TOKYO, JAPAN.
7	MASAHIKO NAKAZONO	204, LIONS-GARDEN-MUSASHIKOSUGI, 5-25, KAMIODANAKA 7-CHOME, NAKAHARA-KU, KAWASHAKI-SHI, KANAGAWA-KEN, JAPAN.
8	YASUMI KIZAKI	310, ESTE-CITY-SHONAM-MUTSUURA-SAMBANKAN, 1950-21, MUTSUURA-CHO, KANAZAWA-KU, YOKOHAMA-SHI, KANAGAWA-KEN, JAPAN.

PCT International Classification Number

F03B 13/10

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	11-337503	1999-11-29	Japan
2	11-234699	1999-08-20	Japan
3	2000-244840	2000-08-11	Japan