Title of Invention

A BEARING COOLING DEVICE FOR A VERTICALLY CONFIGURED WATER PUMP

Abstract

This invention relate to a bearing cooling device for a vertically configured water pump having a rotating shaft connected at one end to a movable impeller supported by a thrust-cum-guide bearing comprising a journal guide bearing and a thrust bearing, the other end being coupled to an electrical drive motor, the device comprising a heat pipe or group of heat pipes comprising a first portion constituting a group of evaporator portions adapted to contain a low boiling point fluid which hereinafter called a working fluid, immersed in a lubricating oil of a bearing housing adjacent to said journal and thrust bearing surroundings and isoinmunicating with said lubricating oil in slow hydrodynamic motion; characterized in that,a second portion constituting a group of condenser nortions located outside said bearing housing being cooled by a tube-in f:ube heat exchanger for receiving and containing a flowing cooling water.

Full Text

F1ELD OF THE INVENTION. The present invention relates to a bearing cooling device for a vertically mounted water pump having a thrust-cum-guide bearing under fluid lubrication and in which a heat pipe is housed for removing the frictional heat. BACKGROUND OF THE INVENTION Generally, in a conventional bearing cooling device in a vertical thrust-cum-guide bearing of a water pump of moderate capacity, lubricating oil is cooled by directly circulating cooling water inside an immersed coil in the bearing housing . The heat generated in the journal and thrust bearing oil film due to shear forces is absorbed by the surrounding lubricating oil which in turn is cooled by the circulating cooling water flowing in the immersed externally finned cooling coils. A Conventional bearing cooling device generally use cooling coil or coils for direct water circulation. However, the bearing cooling device using direct circulation of cooling water under pressure inside the bearing housing has inherent disadvantage in that the cooling water has fair chance of leaking into the surrounding oil and thereby contaminating the oil and altering the lubrication properties and adversely affecting bearing performance and resulting in ultimate bearing failure. Moreover, since the internal cooling surface area of the coil with which the cooling water is in contact is generally very small and hence large quantity of water is needed to take away the heat generated in the lubricating oil thereby increasing the cooling water consumption. Further, provision of separate external heat exchanger with water or air cooling for small to moderate duty bearings is not a worthwhile proposition because of higher costs and added maintenance problems. Other features and advantages of the present invention will be apparent to one skilled in the art from the following description taken in conjunction with the accompanying drawings. SUMMARY OF THE INVENTION A bearing cooling device for a vertically configured water pump having a rotating shaft connected at one end to a movable impeller supported by a thrust-cum-guide bearing comprising a journal guide bearing and a thrust bearing, the other end being coupled to an electrical drive motor, the device comprising: a heat pipe or group of heat pipes comprising a first portion constituting a group of evaporator portions adapted to contain a low boiling point fluid which hereinafter called a working fluid, immersed in a lubricating oil of a bearing housing adjacent to said journal and thrust bearing surroundings and communicating with said lubricating oil in slow hydrodynamic motion; characterized in that a second portion constituting a group of condenser portions located outside said bearing housing being cooled by a tube-in tube heat exchanger for receiving and containing a flowing cooling water. DETAILED DESCRAPTION OF THE INVENTION. According to the first aspect of the present invention, there is provided a bearing cooling device for vertical water pump in which the rotary shaft connects the pump impeller on one end and the electrical motor on the other end, the rotary shaft being supported by a journal guide bearing and a thrust bearing located in a bearing housing partially filled with lubricating oil, the bearing cooling device comprising: an externally finned heat pipe or group of heat pipes with a first portion consisting of evaporator sections immersed in the hot It is therefore an object of the present inventuon to provide a bearing cooling device for the thrust-cum-guide bearing or a vertical water pump wherein the heat generated is due to large shear forces on a relatively thin lubricating oil film occupying the clearance between the rotating shaft and the stationary bearing pads is effectively removedby externally mounted tube-in-tube cooling arrangement surrounding the heat pipe condenser in which water is circulated for dissipating the bearing frictional hear and thereby eliminating the direct circulation of water inside the bearing. It is another object of the present invention to provide a water-free bearing with heat pipes by simple external ventilation above the bearing housing by means of a shrouded shaft mounted fan which circulates ir over the external surface of the heat pipe condenser and thereby efficiently dissipating the bearing frictional heat to the ambient air. A further object of the present invention is to provide a bearing-cooling device with heat pipes by and external means of forced ventilation of the condenser of the heat pipe by a forced draft or an induced draft fan for dissipating the bearing frictional heat to the ambient air. lubricating oil in the bearing housing and surrounding the thrust-cum-guide bearing, a second portion consisting of integrally finned heat pipe or group of heat pipes consisting of a condenser sections integral with the first portion brought out either from the top half cover or from the side wall of the bearing housing having arranged symmetrically over top half covers or adjacent to the bearing housing; said second portion comprising said condenser sections provided with a tube-in -tube cooling means, cooling water being circulated on the external surface of said second portion. The heat pipe itself is filled with heat absorbing working fluid under vacuum and sealed. The heat generated in the bearing oil film due to shear forces acting on the film when the shaft is in rotation is absorbed by the surrounding oil as sensible heat and the temperature of the lubricating oil rises. The hot lubricating oil gives away the heat by convection to the first portion comprising of evaporator portions of the heat pipe or group of heat pipes located in hot oil which heat is conducted away from the finned surface to the working fluid inside the first portion causing evaporation of the working fluid. The vapors move to the cooler second portion of the heat pipe or group of heat pipes comprising condenser sections where the heat is released to the cooling water circulating in the tune-in -tube cooler. The working fluid inside said heat pipe or group of heat pipes thereby condenses and returns to the first portion via a circumferential wick structure lining the internal wall of the heat pipe and assisted by gravity. The thermodynamic cycle of evaporation and condensation repeats continuously and the heat generated in the lubricating oil is very efficiently removed by the heat pipe or group of heat pipes and dissipated to the cooling water circulating in the tube-n tube cooler located outside the bearing housing. According to a second aspect of the present invention, there is provided a bearing cooling device for a vertical water pump in which the rotary shaft is directly connected to a pump impeller on one end and the electric motor on the other end and supported in between by a thrust-cum guide bearing located in a bearing housing partially filled with lubricating oil, the bearing cooling device comprising an externally finned heat pipe or group of heat pipe or group of heat pipes with a first portion consisting evaporator sections immersed in the hot lubricating oil in the bearing housing and surrounding group of heat pipes consisting of condenser sections integral with the first portion and brought out either from the top half cover or from the side wall of the bearing housing and arranged symmetrically and circumferentially over top half covers; said second portion comprising the heat pipe condenser sections provided with ventilation from a shaft mounted and a shrouded fan which produces pressure drop and thereby generates adequate air movement over the second portion of the finned condenser sections of the heat pipe or group of heat pipes and thus dissipates the frictional heat to the surroundings. The heat pipe itself is fitted with heat absorbing working fluid under vacuum and sealed. The heat generated in the bearing oil film due to shear forces acting on the film when the shaft is in rotation is absorbed by the surrounding oil as sensible heat and the temperature of the oil rises. The hot lubricating oil gives away the heat by convection to the first portion comprising of evaporator portions of the heat pipe or group of heat pipes located in hot oil which heat is conducted away from the finned surface to the working fluid inside the first portion causing evaporation causing evaporation of the working fluid. The vapors move to the second portion of the heat pipe or group of heat pipes comprising condenser sections which are exposed to an air blast from the shrouded shaft mounted fan which condenser portions and dissipate the bearing frictional heat. According to a third aspect of the present invention, there is provided a bearing cooling device for a in vertical water pump in which the rotary shaft is directly connected to a pump impeller on one end and the electric motor on the other end and supported in between by a thrust-cum-guide bearing, the bearing cooling device comprising: an externally finned heat pipe or group of heat pipes with a first portion consisting of evaporator sections immersed in the hot lubricating oil in the bearing housing and surrounding the thrust cum guide bearing; a second portion consisting of integrally finned heat pipe or group of heat pipes consisting of condenser sections integral with the first portion and brought out either from the top half cover or from the side wall of the bearing housing arranged over top half covers or adjacent to the bearing housing; the said second portion comprising the condenser sections provided with ventilation by a separate forced draft or induced draft fan mounted with a support directly on the second portion of the finned condenser sections the fan itself producing pressure drop and thereby generating air movement over the second portion of the finned condenser sections of the heat pipe or group of heat pipes and thus dissipating the frictional heat to the surroundings. The heat pipe itself is filled with heat absorbing working fluid under vacuum and sealed. The heat generated in the bearing oil film due to shear forces acting on the film when the shaft is in rotation is absorbed by the surrounding oil as sensible heat and the temperature rises. The hot lubricating oil gives away the heat by convection to the first portion evaporator portions of the heat pipe or group of heat pipes located in hot oil which heat is conducted away from the finned surface to the working fluid inside the first portion causing evaporation of the working fluid. The vapors move to the second portion of the heat pipe or group of heat pipes comprising condenser sections which are exposed to an air blast from the separately mounted forced draft or induced draft fan which can displace fresh air across the finned condenser portions and dissipate the bearing frictional heat. In a bearing cooling device according to the features of the invention, the first portion of the heat pipe or group of heat pipes consisting of the circular evaporator sections is finned with a closely spaced high fin structure while the second portion of the heat pipe or group of heat pipes is also similarly finned with closely spaced high fin structure. In order to attain the above objects, according to the second and third aspects of the present invention in vertical water pump in which the rotary shaft is directly connected to a pump impeller on one end and the electric motor on the other end and supported in between by a thrust cum guide bearing a externally finned heat pipe or group of heat pipes with first portion consisting of evaporator sections immersed in the hot lubricating oil in the bearing housing and surrounding the thrust-cum-guide bearing; the second portion consisting of integrally finned heat pipes or group of heat pipes consisting of condenser sections integral with the first portion and brought out either from the top half cover or from the side wall of the bearing housing and arranged symmetrically over top half covers or adjacent to the bearing housing; said second portion of the device comprising the condenser sections are provided with ventilation from a shaft mounted and shrouded fan which produces enough pressure drop and thereby generates air circulation over the second portion of the finned condenser sections of the heat pipe or group of heat pipes an thus dissipates the frictional heat to the surroundings. The heat pipe itself is filled with heat absorbing working fluid under vacuum and sealed. The heat generated in the bearing oil film due to shear forces acting on the film when the shaft is in rotation is absorbed the surrounding oil as sensible heat and the temperature rises. The hot lubricating oil gives away the heat by convection to the first portion comprising evaporator portions of the heat pipe or group of heat pipes located in hot oil which heat is conducted away from the finned surface to the working fluid inside the first portion causing evaporation of the working fluid. The vapors move to the second portion of the heat pipe or group of heat pipes comprising condenser sections exposed to an air blast from the shrouded shaft mounted fan which can displace adequate fresh air across the finned condenser portions and dissipate the bearing frictional heat. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS. The accompanying drawings, which are incorporated in and constitute part of this specification illustrate three embodiments of the present invention and, together with the description, serve to explain the principle of the invention. OF THE DRAWINGS: FIG.l is a sectional view of an embodiment of the bearing cooling structure of the vertical thrust-cum-guide bearing for water pump; FIG.2 is a partly sectioned view of the heat pipe cooling device of the first embodiment; FIG. 3 is a solid pictorial view of the heat pipe of the first embodiment; FIG.4 is a sectional view of a further embodiment of the bearing cooling device of the vertical thrust-cum-guide bearing for water pump; FIG. 5 is a partly sectioned view of the cooling device of the second embodiment; FIG. 6 is a solid pictorial view of the heat pipe of the second embodiment; FIG.7 is a sectional view of a still further embodiment of the bearing cooling device of the vertical thrust-cum-guide bearing for water pump; FIG. 8 is a partly sectioned view of the heat pipe of the heat pipe cooling structure of the third embodiment; FIG. 9 is a solid pictorial view of the heat pipe of the third embodiment; FIG. 10 is a sectional view of the bearing cooling device of the conventional type for vertical thrust cum guide bearing for water pump; DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS. Referring to the drawings, embodiments of the bearing cooling device of the vertical shaft thrust cum guide bearing according to the present invention will be described Tiereunder. First, an embodiment of the bearing cooling device of the vertical shaft water pump according to the present invention will be described in detail by referring to FIGS. 1 through 3, in which: FIG.l is a sectional view of the bearing cooling device with the bearing housing and the journal and thirst bearings, FIG. 2 is a partly sectioned view of the heat pipe cooling structure. FIG. 3 is a solid pictorial view of the^ heat pipe cooling device. In these drawings, the same parts as those in FIG. 10 for the conventional bearing cooling device arencdrrespondingly referenced. In FIG,. 1, a rotary shaft 16 is supported by a journal bearing 3 and a thrust bearing 4 which are housed in a bearing housing 2 standing on the base plate 1. Lubricating oil 17 is sealed in the bearing housing 2. The collar 7 surrounds the rotating shaft 16. FIG. 1 provides upper half cover plates 5 and 6. The journal bearing pads of the journal bearing 3 are provided with journal bearing stop 8 while the thrust bearing pads of the thrust bearing pads of the thrust bearing 4 are provided with journal bearing stop 8 while the thrust bearing pads of the thrust bearing 4 are provided with a thrust bearing stopper 9. The half cover plates 5 and 6 are joined to the bearing housing 2 with cover tap bolts 10. Bottom bearing sleeve 11 is held to the base plate 1 by sleeve tap bolts 12. The bearing shroud 13 is held to the bearing housing 2 with shroud tap bolts 14. The 'O' ring 15 located on the base plate 1 seals the lubricating oil 17 in the bearing house 2. FIG. 1 further provides the heat pipe or group of heat pipe evaporator portions 18 positioned in the lubricating oil 17 adjacent to the journal bearing 3 and above the thrust bearing 4 and enters the top cover plate 5. The heat pipe or group of heat pipe condenser portions 20 are typically positioned on the top half cover plates 5 and 6 and are integral with the bottom evaporator portions 18 connected by the adiabatic sections 19. The evaporator portion or portions 18, the condenser portion or portions 20, the adiabatic section or sections 19 together constitute the heat pipe or group of heat pipes. The condenser portions 20 are surrounded by a tube -in- tube water jacket 21 which is provided with inlet connection 22 and outlet connection 23 and joined to the condenser portions 20 by means of a flange connection 24. Referring FIG. 2, where the cooling device alone is shown, the heat pipe condenser portions 20 are with or without integral external low fins 29 when wter is the cooling medium depending on the flow rate of the cooling medium. The heat pipe evaporator portions 18 have closely spaced high fins 25 which increase the heat transfer area and thereby permit more heat input over a given length of the evaporator portion 18 while compensating for the poor heat transfer properties of lubricant oils. The heat pipe condenser portions 20 are equipped with a tube-n-tube water jacket 21 appropriately supported over the half cover plates 5 and 6. The tube-in-tube water jacket 21 is provided with hydraulic inlet connection 22 and outlet connection 23 for cooling water circulation over the condenser portions 20. Referring to FIG. 2, a wick structure 26 typically several layers of wire mesh held by a spring structure 27 or axial wall grooves or a composite of both is provided to serve as a permeable medium for the production of a capillary force and for the even distribution of working fluid 28 is of materials compatible with the heat pipe container material as well as compatible with the working fluid 28. The wick 26, the spring 27 and the working fluid 28 are sealed under vacuum inside the heat pipe. While the wick 26 is an essential and necessary part of the evaporator portion 18 as well as the adiabatic section 19 to conduct and distribute the working fluid 28, it is not an essential part of the condenser portions 20. When the rotary shaft 16 rotates and exerts thrust force on the thrust bearing 4 through the liquid film therebetween the relatively thin liquid film experiences a shear stress and generates frictional heat which is transmitted to the surrounding liquid lubricant 17 by heat conduction and by heat convection. Like wise the journal guide bearing 3 also experiences heat generation due to sliding shear stress in the relatively thin liquid film which heat is also transmitted to the surrounding liquid lubricant 17 by conduction and convection. The heated lubricating oil 17 which is in contact with the heat pipe evaporator portions 18 gives away the heat to the finned evaporator external surface. The heat is conducted by the heat pipe wall to the working fluid inside the heat pipe evaporator portions 18 vaporizing a small portion of the said working fluid inside the heat pipe evaporator portions 18 vaporizing a small portion of the said working fluid 28 due to latent heat absorption. The vapors rise to the relatively cool heat pipe condenser portion 20 where the vapors condense releasing the latent heat to the surrounding cooling water. The condensate of the working fluid 28 inside the heat pipe condenser portion 20 returns through the wick structure 26 to the evaporator 18 thus completing one closed thermodynamic cycle of evaporation and condensation during which a definite amount of heat is transmitted from the bearing lubricating oil 17 to the cooling medium keeping the bearing components at a predetermined mandatory temperature. The above described heat pipe operation repeats continuously when the rotary shaft 16 is in motion and the bearing cooling device is functioning. FIG. 3 provides a sectioned solid pictorial view of the bearing cooling device of the first embodiment. Next, another embodiment of the bearing cooling device for a vertical thrust-cum-guide bearing for a water pump is described in detail hereunder by referring to FIGS. 1 through 6, in which FIG.4 is a sectional view of the bearing cooling device, FIG.5 is a partly sectioned view of the cooling device and FIG.6 is a solid pictorial view of the heat pipe itself. FIG. 4, a rotary shaft 16 is supported by a journal bearing 3 and a thrust bearing 4 which are housed in a bearing housing 2 standing on the base plate 1. Lubricating oil 17 is sealed in the bearing housing 2. The collar 7 surrounds the rotating shaft 16. FIG. 4 further provides the second embodiment of the cooling device wherein the heat pipe oT^poup of heat pipe evaporator portions 18 are positioned in the lubricating oil 17 adjacent to the journal bearing 3 and above the thrust bearing 4 and enter the top half cover plate 5. The heat pipe or group of heat pipe condenser portions 20° arlTfyplcaTly positioned on the top half covers 5 and 6 and are integral with the bottom evaporator portions 18 connected by the adiabatic section 19. The evaporator portion 18, the condenser portions 20, the adiabatic portion 19 together constitute the heat pipe. The distinct feature of the second embodiment of the cooling device is that the condenser portions 20 are identical in construction with the evaporator portions 18 and are connected by the adiabatic portions 19. Further more, the novelty of the second embodiment is that the condenser portions 20 are now air cooled by shaft mounted fan. The heat pipe evaporator portions 18 have closely spaced high fins 25 which increase the heat transfer area and thereby permit more heat input over a given length of the evaporator portion 18 while compensating for the poor heat transfer properties of lubricant oils. Likewise, the heat pipe condenser portions 20 have closely spaced high fins 25 which increase the heat transfer area for air cooling and thereby permit more heat input over a given length of the condenser portions 20 and thus compensating for the poor heat transfer properties of circulating ambient air. The air circulation around the condenser portions 20 is achieved by a shaft-mounted fan 30 enclosed in a fan shroud 31 supported on pillars 32. The fan shroud 31 has provision for axial entry and radial exit of cooling air. Referring to Fig. 5, a wick structure 26 typically several layers of wire mesh held by a spring structure 27 or axial wall grooves or a composite of both is provided to serve as a permeable medium for the production of a capillary force and for the even distribution of working fluid 28 is of materials compatible with the heat pipe container material as well as compatible with the working fluid 28. The wick 26, the spring 27 and the working fluid 28 are sealed under vacuum inside the said heat pipe. Whereas, the wick 26 is an essential part of the evaporator portion 18 and adiabatic section 19 to distribute and conduct the working fluid 28, it is not an essential part of the condenser portions 20. When the rotary shaft 16 rotates and exerts thrust force on the thrust bearing 4 through the liquid film therebetween the relatively thin liquid film experiences a shear stress and generates frictional heat which is transmitted to the surrounding liquid lubricant 17 by heat conduction and heat convection. Likewise the journal guide bearing 3 also experiences heat generation due to sliding shear stress in the relatively thin liquid film which heat is also transmitted to the surrounding liquid lubricant 17 by conduction and convection. The heat lubricating oil 17 which is in contact with the heat pipe evaporator portions 18 gives away the heat to the finned evaporator external surface. The heat is conducted by the heat pipe wall to the working fluid inside the heat pipe evaporator portions 18 vaporizing a small portion of the said working fluid due to latent heat absorption. The vapors rise to the relatively cool heat pipe condenser portion 20 cooled by a shaft mounted fan 29 whereby the vapors of the working fluid 28 condense releasing the latent heat which is transmitted to the surrounding circulating air. The condensate of the working fluid 28 collected inside the heat pipe condenser 20 returns through the wick structure 26 under the influence of gravity to the evaporator portion 18 thus completing one closed thermodynamic cycle of evaporation and condensation during which a definite amount of frictional heat is transmitted from the bearing lubricating oil 17 and dissipated to the cooling medium keeping the bearing components at a predetermined mandatory temperature. The above described heat pipe operation repeats continuously when the rotary shaft 16 is in motion and the bearing cooling device is functioning. Fig. 6 provides a three dimensional pictorial view of the bearing cooling device of the second embodiment. Next yet another embodiment of the bearing cooling device for a vertical thrust-cum-guide bearing for a water pump is described in detail hereunder by referring to FIGS. 1 through 9, in which FIG.7 is a sectional view of the bearing cooling device and FIG. 9 is a three dimensional pictorial view of the heat pipe itself. In Fig. 7, a rotary shaft 16 is supported by a journal bearing 3 and a thrust bearing 4 which are housed in a bearing housing 2 standing on the base plate 1. Lubricating oil 17 is sealed in the bearing housing 2. The collar 7 surrounds the rotating shaft 16. Fig. 7 further provides the third embodiment of the cooling device wherein the heat pipe or group of heat pipe evaporator portions 18 are positioned in the lubricating oil 17 adjacent to the journal bearing 3 and above the thrust bearing 4 and enter the top half cover plate 5. The heat pipe or group of heat pipe condenser portions 20 are typically positioned on the top half covers 5 and 6 and are integral with the bottom evaporator portions 18 connected by the adiabatic section 19. The evaporator portion 18, the condenser portions 19, the adiabatic portion 20 together constitute the heat pipe. The distinct feature of the third embodiment of the cooling system is that the condenser portions 20 differ in construction compared to the construction of the evaporator portion 18 in that they are arranged as a bank of vertical finned tubes connected by top header 36 and bottom header 37 which are in turn connected to the evaporator portions 18 by independent adiabatic sections 19. Further more, the novelty of the third embodiment is that the condenser portions 20 are now air cooled by a separately installed axial fan 33 powered by mains supply and capable of handling higher bearing heat duties. The heat pipe evaporator portions 18 have closely spaced high fins 25 which increase the heat transfer area and thereby permit more heat input over a given length of the evaporator portion 18 while compensating for the poor heat transfer properties of lubricant oils. Likewise, the heat pipe condenser portions 20 have closely spaced high fins 25 which increase the heat transfer area for air cooling and thereby permit more heat input over a given length of the condenser portions 20 and thus compensating for the poor heat transfer properties of circulating ambient air. The air circulation around the condenser portions 20 is achieved by the axial fan 33 enclosed in a fan shroud 34 and mounted directly on the condenser ducting 35 provided over the condenser portion 20. The top header or headers 36 and bottom header or headers 37 connect the vertical condenser portions 20. Referring to FIG. 8, a wick structure 26 typically several layers of wire mesh held by a spring structure 27 or axial wall grooves or a composite of both is provided to serve as a permeable medium for the production of a capillary force and for the even distribution of working fluid 28 is of materials compatible with the heat pipe container material as well as compatible with the working fluid 28. The wick 26, the spring 27 and the working fluid 28 are sealed under vacuum inside the said heat pipe. Whereas the wick 26 is an essential part of the evaporator portion 18 and the adiabatic section 19 to distribute and conduct the working fluid 28, it is not an essential part of the condenser portions 20. When the rotary shaft 16 rotates and exerts thrust force on the thrust bearing 4 through the liquid film therebetween the relatively thin liquid film experiences a shear stress and generates frictional heat which is transmitted to the surrounding liquid lubricant 17 by heat conduction and heat convection. Likewise the journal guide bearing 3 also experiences heat generation due to sliding shear stress in the relatively thin liquid film which heat is also transmitted to the surrounding liquid lubricant 17 by conduction and convection. The heated lubricating oil 17 which is in contact with the heat pipe evaporator portions 18 gives away the heat to the finned evaporator external surface. The heat is conducted by the heat pipe wall to the working fluid inside the heat pipe evaporator portions 18 vaporizing a small portion of the said working fluid due to latent absorption. The vapors rise to the relatively cool heat pipe condenser portion 20 cooled by a separately mounted fan whereby the vapors of the working fluid 28 condense releasing the latent heat which is transmitted to the surrounding circulating air. The condensate of the working fluid 28 collected inside the heat pipe condenser sections 20 returns through the wick structure 26 under the influence of gravity to the evaporator portion 18 thus completing one closed thermodynamic cycle of evaporation an condensation during which a definite amount of frictional heat is transmitted from the bearing lubricating oil 17 and dissipated to the cooling medium keeping the bearing components at a predetermined mandatory temperature. The above described heat pipe operation repeats continuously when the rotary shaft 16 is in motion and the bearing cooling device is functioning. Fig. 9 provides a three dimensional pictorial view of the bearing cooling device of the second embodiment. Fig. 10 depicts the prior art with a cooling coil or coils 38 connected to the inlet connection 22 and to outlet connection 23 for direct water circulation under pressure. According to an aspect of the present invention, the heat generated in the oil film of journal guide bearing and the heat generated in the oil film of thrust bearing is transported by means of the heat pipe to the cooling medium like water where the cooling is undertaken by the cooling unit located outside the bearing housing thereby preventing the lubricating oil from coming in contact with the cooling medium like water. According to another aspect of the present invention, the heat generated in the oil film of journal guide bearing and the heat generated in the oil film of thrust bearing is transported by means of the heat pipe to the cooling medium like air where the cooling is undertaken by the cooling unit located outside the bearing housing where the air circulation is achieved by means of a separate fan powered by independent power supply. CLAIM; 1. A bearing cooling device for a vertically configured water pump having a rotating shaft connected at one end to a movable impeller supported by a thrust-cum-guide bearing comprising a journal guide bearing and a thrust bearing, the other end being coupled to an electrical drive motor, the device comprising: a heaf pipe or group of heat pipes comprising a first portion constituting a group of evaporator portions adapted to contain a low boiling point fluid which hereinafter called a working fluid, immersed in a lubricating oil of a bearing housing adjacent to said journal and thrust bearing surroundings and communicating with said lubricating oil in slow hydrodynamic motion; characterized in that a second portion constituting a group of condenser portions located outside said bearing housing being cooled by a tube-in tube heat exchanger for receiving and containing a flowing cooling water. 2. The device as claimed in Claim 1 wherein said second portion of heat pipe or group of heat pipes finned externally and located one above the other or one adjacent to the other with a clamping and immersed in the lubricating oil surrounding said bearing. 3. The device as claimed in Claim 2 wherein said second portion of heat pipe or group of heat pipes is integrally connected with said first portion in liquid and vapor communicating relationship and having a cooling arrangement for said flowing water circulation. 4. The device as claimed in Claim 1 comprising a tube-in-tube heat exchanger outside side bearing housing for circulating the cooling water over the second portion for removing a frictional heat generated in the bearing. 5. A bearing cooling device for a vertically mounted water pump as substantially herein described and illustrated with the help of accompanying drawings.

Documents:

1147-del-2003-abstract.pdf

1147-del-2003-claims.pdf

1147-del-2003-complete specification (granded).pdf

1147-del-2003-correspondence-others.pdf

1147-del-2003-correspondence-po.pdf

1147-del-2003-description (complete).pdf

1147-del-2003-drawings.pdf

1147-del-2003-form-1.pdf

1147-del-2003-form-13.pdf

1147-del-2003-form-19.pdf

1147-del-2003-form-2.pdf

1147-del-2003-form-3.pdf

1147-del-2003-gpa.pdf