Title of Invention	ELECTRIC UNIT
Abstract	The invention relates to an electric unit (1) which comprises a machine module (2) provided with an electric machine (3) comprising a stator (4) and a rotor. A machine housing (7) of the machine module (2) receives the electric machine (3). A cooling module (19) comprises a cooling housing (21), which is fluidically connected to the machine housing (7) by means of a first cooling fluid connection area (20) in a housing wall (17) of the machine housing (7) and to at least one second cooling fluid connection area (23) in the housing wall (17) of the machine housing (7). The inside of the machine housing (7) can be fluidically connected to the inside of the cooling housing (21) in one section of the housing wall (17), which is oriented towards the cooling housing (21), by means of at least one third cooling fluid connection area (25) comprising at least one cooling fluid through-opening (26). Various cooling module variants can use said third cooling fluid connection area (25) when other cooling module variants, which can be used in exchange with the cooling module (19) in the machine module (2), do not use the third cooling fluid connection area (25). As a result, an electric unit (1), a machine module (2) therefore and a set comprising a plurality of different cooling modules, which can meet altered cooling requirements having reduced structural and constructural costs, can be produced.

Title of Invention

ELECTRIC UNIT

Abstract

The invention relates to an electric unit (1) which comprises a machine module (2) provided with an electric machine (3) comprising a stator (4) and a rotor. A machine housing (7) of the machine module (2) receives the electric machine (3). A cooling module (19) comprises a cooling housing (21), which is fluidically connected to the machine housing (7) by means of a first cooling fluid connection area (20) in a housing wall (17) of the machine housing (7) and to at least one second cooling fluid connection area (23) in the housing wall (17) of the machine housing (7). The inside of the machine housing (7) can be fluidically connected to the inside of the cooling housing (21) in one section of the housing wall (17), which is oriented towards the cooling housing (21), by means of at least one third cooling fluid connection area (25) comprising at least one cooling fluid through-opening (26). Various cooling module variants can use said third cooling fluid connection area (25) when other cooling module variants, which can be used in exchange with the cooling module (19) in the machine module (2), do not use the third cooling fluid connection area (25). As a result, an electric unit (1), a machine module (2) therefore and a set comprising a plurality of different cooling modules, which can meet altered cooling requirements having reduced structural and constructural costs, can be produced.

Full Text	Description Title of the invention: Set comprising a plurality of cooler modules for assembly with a machine module Text: The invention relates to a set comprising a plurality of cooler modules, for assembly with a machine module. An electrical appliance having a machine module and a cooler module is known from JP 60-219 939 A. There, the electrical appliance has a heat exchanger through which a flow passes along a zigzag path, starting from the first cooling fluid connection zone, to the second cooling fluid connection zone. The cooling of known electrical appliances such as these in each case is matched to the machine module that is used. As soon as it is found that a specific cooling technique is no longer adequate for the machine module, the cooling for the electrical appliance must be completely redesigned. Further electrical appliances are known from JP 57-040344 A, JP 61-285039 A and WO 01/17094 Al. One object of the present invention is to provide a choice of cooling variants matched to the particular application, for a machine module, without having to make any design changes to the machine module for this purpose. According to the invention, this object is achieved by a set comprising a plurality of cooler modules as claimed in claim 1. The first cooler module variant allows open air cooling from both ends of the electrical machine. The second cooler module variant allows closed air cooling with a heat exchanger from both ends of the electrical machine. The third cooler module variant allows open air cooling flowing longitudinally through the electrical machine. The fourth cooler module variant allows closed air cooling flowing longitudinally through the electrical machine, with a heat exchanger. Depending on the ingress protection class of the electrical machine, it is then possible, for example to choose an open or closed type of cooling. A closed electrical machine can be operated with an air-air heat exchanger or with an air-water heat exchanger. The maximum cooling power based on VDE 0530 and thus the maximum machine power are achieved with an open machine with forced- draft ventilation and with air-water cooling. With a correspondingly reduced power, an air-air cooled machine offers the advantage of a closed type in combination with air cooling. Electrical machines are manufactured with different numbers of poles and are therefore designed for different rotation speeds. These machines can then the operated with a power supply system with a fixed rotation speed or from a converter with a variable rotation speed. Depending on the number of pole pairs and when converters are used for operation, it may also be advantageous, depending on the desired rotation-speed range, to cool the machine with the air flow from both ends, or from one end. In this case, the air resistance of the cooler module also plays an important role. Depending on the cooling type and number of pole pairs and the rotation speed it is possible according to the invention to choose the most efficient cooling variant with one and the same machine housing. Cooler modules with cooling air guides which do not require the third cooling fluid connection zone for the machine housing, seal them simply with the respective sealing device, so that the cooling air flows solely through the two remaining cooling fluid connection zones to the machine housing. A refinement of cooler module variants as claimed in claim 2 is particularly advantageous for cost-effective production of these cooler module variants. Alternatively it is possible to provide a tube connection in order to supply cooling air to the machine housing. When air is supplied at one end, that is to say it flows longitudinally through the electrical machine, the third cooling fluid connection zone is closed with the aid of the sealing device. In the case of air cooling of both ends, the air is supplied via tube connections to the first and second cooling fluid connection zone, and the air is carried away via the tube connection to the third cooling fluid connection zone. Heat exchangers as claimed in claims 3 and 4 are adequate for many cooling requirements, even relatively demanding cooling requirements. The design of the machine housing of the machine module with three cooling fluid connection zones makes it possible to produce different variants of the cooling air guidance in the machine housing. These different cooling air guidance variants can then be combined with appropriate cooler modules, so that it is possible to take account of individual cooling requirements. The electrical appliance according to claim 5 can thus be equipped with different cooling techniques for the respective cooler module, without any need to make any physical changes for this purpose to the machine module, in particular without having to make any physical changes to the machine housing. By way of example, the following cooling techniques can be implemented with the same machine housing, just by adaptation of the cooler module: open air cooling from both ends of the electrical machine, closed air cooling with an air- air heat exchanger from both ends of the electrical machine, closed air cooling with an air-water heat exchanger from both ends of the electrical machine, open air cooling flowing longitudinally through the electrical machine, closed air cooling flowing longitudinally through the electrical machine with an air-air heat exchanger, closed air cooling flowing longitudinally through the electrical machine with an air-water heat exchanger. The cooler module either has only the function of cooling fluid guidance or includes active cooling elements such as heat exchangers. A standardized machine housing can be used for all of these cooling techniques. An electric motor, or alternatively a generator, may be used as the electrical machine. A machine housing as claimed in claim 6 provides effective stator cooling. A machine housing as claimed in claim 7 allows cooling fluid guidance in which cooling fluid is not only supplied to or carried away from the ends of the machine, but is also passed via a central section of the machine housing. The cooling fluid can be supplied to this central section of the machine housing via the circulating and tangential cooling fluid flow component. This allows on the one hand cooling from both ends, and as well as cooling which flows through the machine from one end, on the other hand to be provided with one and the same machine housing. Webs as claimed in claim 8 offer a simple design capability to ensure a circulating cooling fluid flow. t Aperture openings in the webs as claimed in claim 9 result in defined tangential cooling fluid guidance. Air as the cooling fluid as claimed in claim 10 represents the simplest variant for cooling within the machine housing. Alternatively, it is also possible to use a different cooling fluid, in particular a cooling gas other than air. In principle, it is also possible to use a cooling liquid. A fan as claimed in claim 11 is advantageous when the rotor movement itself does not preset or does not adequately preset the desired flow direction of the cooling fluid. Exemplary embodiments of the invention will be explained in more detail in the following text with reference to the accompanying drawing, in which: Figure 1 shows a perspective view of a detail of an electrical appliance having a machined module and a first cooler module variant, which represents part of a set comprising a plurality of cooler modules for assembly FIGURE 2 shows a perspective view of a detail of a further electrical appliance having the machine module as shown in FIGURE 1 and of a second cooler module variant of the cooler module set, which has an air- air heat exchanger; FIGURES 3-6 show perspective views of a detail of the machine module as shown in FIGURE 1, with further cooler module variants, and FIGURE 7 shows a perspective, enlarged view, of a detail of a machine housing for the machine module. FIGURE 1 shows a perspective view of a detail of a drive appliance 1 as an example of an electrical appliance. This is a machine with a cooling circuit. The electrical appliance 1 has a motor module 2 illustrated at the bottom of FIGURE 1, as an example of a machine module. This has an electric motor 3 as an example of an electrical machine of which only a stator 4 to be precise the right-hand cutaway half of it, is illustrated in FIGURE 1. The stator 4 is in the form of a laminated core. As is known per se, the stator 4 has a plurality of aperture openings 5 through which fluid can flow radially through the stator 4. The rotor, which is not illustrated, also has corresponding aperture openings, which are known per se. Furthermore both the stator 4 and the rotor have passages 6 which run both through the stator 4 and through the rotor in the axial direction and through which fluid can likewise flow. The electric motor 3 is accommodated in a machine or motor housing 7. The drawing shows only a vertically longitudinally sectioned rear half of this housing. The machine housing 7 has a first end wall 8, on the left in the drawing, and a second end wall 9 on the right in the drawing. Adjacent to the first end wall 8 and at a distance from it, the machine housing 7 has a first intermediate wall 10, in the left in the drawing. Adjacent to the second end wall 9, the machine housing 7 has a second intermediate wall 11, on the right in Figure 7. When the electric motor is assembled, an end shield which is not illustrated, in each case seals the electric motor 3 from the end walls 8, 9, such that it is not possible for any fluid to flow into or out of the machine housing 7 at the end, that is to say at the two ends of the electric motor 3. When the electric motor 3 is assembled, a casing wall 12 of the stator 4 also rests on the intermediate walls 10, 11. The stator casing is sealed on the housing walls via guide walls, which are not illustrated. When the electric motor 3 is assembled, the machine housing 7 is thus subdivided into an axial central section 13 between the two intermediate walls 10, 11 into a first edge section 14 which is shown on the left in the drawing between the first end wall 8 and the first intermediate wall 10, and into a second edge section 15 which is shown on the right in FIGURE 7 between the second intermediate wall 11 and the second end wall 9. In the area of the central section 13, the machine housing 7 has an octagonal cross section at right angles to its longitudinal axis. In the central section 13, the casing wall 12 of the stator 4 rests on the machine housing 7 via webs 16 which run axially between the intermediate walls 10, 11 and are firmly connected to a housing casing wall 17 of the machine housing 7. The external circumference of the stator 4 is fixed to the webs 16. The webs 16 have fluid aperture openings 18 at right angles to their extent direction and parallel to the adjacent section of the housing wall 17. In the illustrated exemplary embodiment, six aperture openings 18 are provided for each web 16. In FIGURE 1, a cooler module 19 of the electrical appliance 1 is arranged above the machine housing 7 and is firmly connected to the machine module 2. The interior of a cooler housing 21 of the cooler module 19 is connected for fluid flow purposes to the first edge section 14 of the machine housing 7 via a first cooling fluid connection zone 20 in an upper section in the drawing, of the housing wall 17 which faces the cooler module 19 and is formed at the cooler end by a cooling fluid supply opening. For this purpose, the cooler housing 21 has an aperture opening 22 in the bottom face in FIGURE 1, which is aligned with the first cooling fluid connection zone 20 of the machine housing 7. Furthermore, the machine housing 7 has a second cooling connection zone 23, which is likewise formed on the motor side by a cooling fluid aperture opening in that housing wall section of the machine housing 7 which faces the cooler module 19. The second edge section 15 of the machine housing 7 is connected for fluid flow purposes to the cooler housing 21 via the second cooling fluid connection zone 23. For this purpose, the cooler housing 21 has a further aperture opening 24, on the bottom face on the right in FIGURE 1. Furthermore, the machine housing 7 has a third cooling fluid connection zone 25 in the housing wall section which faces the cooler module 19. This is located between the first two cooling fluid connection zones 20, 23. The third cooling fluid connection zone is formed on the motor side in the upper wall section in the drawing, that is to say the wall section facing the cooler housing 21, of the central section 13 which has an octagonal cross section, of the machine housing 7 and is subdivided into a plurality, in the illustrated exemplary embodiment into a total of 18, square aperture openings 2 6 arranged in a grid. The central section 13 is connected for fluid flow purposes to the interior of the cooler housing 21 via the third cooling fluid connection zone 25. For this purpose, on the bottom face, the cooler housing 21 has a central aperture opening 27 between the aperture openings 22 and 24. The interior of the cooler housing 21 is subdivided into a first cooler housing area 28, that is to say the upper cooling housing area in FIGURE 1 and into a second cooler housing area 29 which is illustrated centrally at the bottom in FIGURE 1. The two cooling housing areas 28, 29 are separated from one another in a fluid-tight manner by a partition wall 30 in the form of a platform. The latter extends from a bottom intermediate web of the cooler housing 21 which is arranged between the aperture openings 22 and 27, to a further bottom intermediate web of the cooler housing 21 between the aperture openings 27 and 24. The first cooler housing area 28 is connected for fluid flow purposes on the one hand by the aperture openings 22 and 24 to the first cooling fluid connection zone 20, and on the other hand to the second cooling fluid connection zone 23. The second cooler housing area 29 is connected for fluid flow purposes via the aperture opening 27 to the third cooling fluid connection zone 25. The first cooler housing area 28 is connected for fluid flow purposes to the area surrounding the cooler module 19 via inlet openings 31, 32 which are arranged opposite one another at the ends. The second cooler housing area 29 is connected to the area surrounding the cooler module 19 via a bottom outlet opening 33. The outlet opening 33 is aligned with a cutout 34 in the housing section of the machine housing 7 facing the cooler module 19, with this resulting from the octagonal cross section of the central section 13. Open air cooling of the electric motor 3 at both ends in the electrical appliance 1, as shown in FIGURE 1, operates as follows: Air is sucked in via the inlet openings 31, 32 into the first cooler housing area 28 of the cooler housing 21, as indicated by the flow direction arrows 35, 36 in FIGURE 1. A suction effect which results in this inward suction, is created by the rotation of the rotor on the electric motor 3 in the stator 4. The air that is sucked in passes through the first cooling fluid connection zone 20 and the second cooling fluid connection zone 23, that is to say on the one hand it enters the first edge section 14 of the machine housing 7 via the aperture openings 22 and 20, and on the other hand enters the second edge section 15 of the machine housing 7 via the aperture openings 24 and 23. As indicated by the direction of the flow arrows 37, 38, the cooling air enters the central section 13 of the machine housing 7 from there. In this case, the air flows from both ends of the electric motor 3 through the corresponding aperture openings and passages in the rotor and through the aperture openings 5 and the passages 6 in the stator 4. This therefore represents double-ended cooling of the electric motor 3. Furthermore, for example, the cooling air which emerges from the stator 4 passes over the outside of the casing wall 12 of the stator 4. The casing wall 12 is separated from the housing wall 17 by the webs 16, so that fluid can flow between the casing wall 12 and the housing wall 17. This provides efficient air-cooling for the rotor and the stator 4. In the central section 13, the cooling air can flow through the aperture openings 18 in the webs 16 to the aperture openings 26 in the third cooling fluid connection zone 25, as indicated by the flow direction arrows 39, the webs 16 therefore allow cooling air flow between the wall 17. The cooling air which 40. The aperture openings 18 in for circulating and tangential casing wall 12 and the housing transports the waste heat away enters the second cooling housing area 29 from the third cooling fluid connection zone 25 and flows out to the exterior again from the outlet opening 33, from this area, via the cutout 34. FIGURE 2 shows the machine module 2 with a second variant of a cooler module 41. The latter will be described in the following text only where it differs from the cooler module 19. Components which correspond to those which have already been explained above with reference to FIGURE 1 have the same reference numbers and will not be discussed in detail again. A cooler housing 42 of the cooler module 41 is subdivided into a first cooler housing section with two edge sections 43, 44 on the one hand, and the second cooler housing section 45 on the other hand. The edge sections 43, 44 of the cooler housing 42 are arranged above the edge sections 14, 15 of the machine housing 7 in FIGURE 2. The edge section 43 is connected for fluid flow purposes via the aperture opening 22 to the aperture opening in the first cooling fluid connection zone 20 in the machine housing 7. The edge section 44 is connected for fluid flow purposes via the aperture opening 24 to the aperture opening in the second cooling fluid connection zone 23 of the machine housing 7. The second cooler housing section 45 is connected for fluid flow purposes via the aperture opening 27 to the aperture openings 26 in the third cooling fluid connection zone 25 of the machine housing 7. Three supporting walls 48, 49, 50 are arranged parallel to end walls 46, 47 of the cooler housing 42, which are shown on the left and right in FIGURE 2 in the interior of the cooler housing 42. The first supporting wall 48, which is shown on the left in FIGURE 2, is mounted at the bottom on a supporting web of the cooler housing 42, which is arranged between the aperture openings 22 and 27. The supporting wall 48 separates the edge section 43, on the left in FIGURE 2, from the second cooler housing section 45. This separation is not complete, since the supporting wall 48 does not extend as far as the housing wall of the cooler housing 42 shown at the top in FIGURE 2. The second supporting wall 4 9 is mounted on the wall of the cooler housing 42 shown at the top in FIGURE 2, in the second cooler housing section 45. The second supporting wall 49 does not extend as far as the bottom of the cooler housing 42, so that the supporting wall 49 in the second cooler housing section 45 does not represent a barrier for cooling fluid. The third supporting wall 50 is mounted on a bottom supporting web of the cooler housing 42 which is arranged between the aperture openings 27 and 24, and its extend corresponds to that of the first supporting wall 48. Like the first supporting wall 48, the third supporting wall 50 represents a subdivision, which can be overcome for cooling fluid between the second cooler housing section 45 and the edge section 44 on the right in FIGURE 2. Cooling air tubes 51 for secondary cooling air are supported by the end walls 46, 47 and the supporting walls 48 to 50 and passed through the cooler housing 42 parallel to the axis of the electric motor 3. In the exemplary embodiment shown in FIGURE 2 there are a total of eighty cooling air tubes 51. These form an air-air heat exchanger 52. Closed air-circuit cooling is provided at both ends for the electrical appliance 1 shown in FIGURE 2 as follows: Primary cooling air enters the machine housing 7 via the first cooling fluid connection zone 20 and the second cooling fluid connection zone 23, as indicated by flow direction arrows 53, 54 in FIGURE 2 . The further cooling air flow in the machine housing 7 in the electrical appliance 1 as shown in FIGURE 2 corresponds to the cooling air flow for the cooling of the electrical appliance 1 shown in FIGURE 1 as indicated by the flow direction arrows 39, 40. After passing through the third cooling fluid connection zone 25, the cooling air which transports the heat away enters the second cooler housing section 45 of the cooler housing 42, as indicated by flow direction arrows 55. In the second cooler housing section 45 and in the two edge sections 43, 44 of the first cooler housing section of the cooler housing 42, heat is now exchanged from the heat-emitting primary cooling air to the heat-receiving secondary cooling air which flows through cooling air tubes 51. The primary cooling air in this case bypasses the separating walls 48, 50 and once again flows in the direction of the first cooling fluid connection zone 20 on the one hand, and the second cooling fluid connection zone 23 on the other hand, as indicated by flow direction arrows 56, 57. This completes the cooling circuit of the primary cooling air. The flow direction of this cooling circuit results from the suction effect of the electric motor 3. A further variant of a cooler module 58 will be described in the following text with reference to FIGURE 3. The description covers only the differences between the cooler module 58 and the cooler module 41 shown in FIGURE 2. Components which correspond to those which have already been explained above with reference to FIGURES 1 and 2 have the same reference numbers and will not be discussed in detail again. Instead of an air-air heat exchanger, the cooler module 58 has an air-water heat exchanger 59. This has two laminate modules 60, 61, which are illustrated schematically in FIGURE 3 as blocks with a rectangular cross section. As is known, for example, from motor vehicle radiators, the cooling laminates of the laminate modules 60, 61 through which cooling water flows are in the form of flat structures, which are all aligned essentially parallel to the main extent plane. This main extent plane is at the same time at right angles to the bottom of a cooler housing 62 of the cooler module 58, and on the other hand is at right angles to end walls 63, 64 of the cooler housing 62 with these being shown on the left and right in FIGURE 3. This alignment of the laminate results in the flows of the primary cooling air being impeded as little as possible. The water heat exchanger 59 is supported by a supporting wall 65 in the form of a platform. A contact wall 66 of the supporting wall 55 on which the water heat exchanger 59 rests is designed such that air can pass through it, that is to say it has aperture openings for the primary cooling air. These aperture openings distinguish the supporting wall 65 from the separating wall 30 in the cooler housing 21 of the cooler module 19 shown in FIGURE 1. Otherwise, the form and the installation of the supporting wall 65 correspond to those for the separating wall 30. The supporting wall 65 separates a first cooler housing section of the cooler housing 62 with the edge sections 43, 44 from the second, central cooler housing section 67, which is bounded at the top by the supporting wall 65 in FIGURE 3. Closed air-water cooling at both ends for the cooler module variant shown in FIGURE 3 operates as follows: The primary cooling air flow in the machine housing 7 corresponds to that which has been described in conjunction with the cooler module 41 shown in FIGURE 2. The heated cooling air enters the second cooler housing section 67 of the cooler housing 62 from the third cooling fluid connection zone 25, from where it enters the laminate modules 60, 61 through the contact wall 66 as indicated by flow direction arrows 68, 69. In the laminate modules 60, 61, the cooling air emits its heat to the cooling water of the water heat exchanger 59 as it flows through the laminates. From the laminate modules 60, 61 the cooling air that has been cooled down flows into the edge sections 43, 44 of the cooler housing 62 from where it once again flows in the direction of the aperture openings 22, 24 as indicated by flow direction arrows 70, 71. A third variant of a cooler module 72 will be described in the following text with reference to FIGURE 4 in which case this third variant can be mounted on the machine module 2 in order to complete an electrical appliance 1 instead of the cooler modules 19, 41 and 58. Components of the cooler module 72 which correspond to those which have already been explained above in conjunction with FIGURES 1 to 3 have the same reference numbers and will not be discussed in detail again. A cooler housing 73 of the cooler module 72 is subdivided into a first, bottom cooler housing area 74 and a second, cooler housing area 75, which is essentially arranged above it. The two cooler housing areas 74, 75 are separated from one another in a fluid-tight manner via a separating wall 7 6 within the cooler housing 73. The first cooler housing area 74 is connected for fluid flow purposes to the area surrounding the cooler module 72 via an inlet opening 77. The size and arrangement of the inlet arrangement 77 correspond to those of the outlet opening 33 of the cooler module 19 shown in FIGURE 1. The first cooler housing area 74 is connected for fluid flow purposes to the second cooling fluid connection zone 23 via the aperture opening 24. A section of the second cooler housing area 75 on the left in FIGURE 4 is connected for fluid flow purposes to the first cooling fluid connection zone 20 of the machine housing 7 via the aperture opening 22. The second cooler housing area 75 is connected to the area surrounding the cooler module 72 via an outlet opening 78. The size and arrangement of the outlet opening 78 correspond to those of the inlet opening 32 of the cooler housing 21 shown in FIGURE 1. The separating wall 76 has a first separating wall section 79, which is mounted on a bottom supporting web of the cooler housing 73 between the aperture opening 22 and the inlet opening 77, and rises steeply from the bottom, so that the second cooler housing area 75 initially widens continuously, starting from the aperture opening 22. A second separating wall section 80 of the separating wall 76 is adjacent to the first separating wall section 79. This is arranged such that it falls away slightly in the cooler housing 73 so that the second cooler housing area 75 widens continuously towards the outlet opening 78, starting from the connection between the two separating wall sections 79, 80. Apart from the bottom openings 22, 24 and 77, the bottom of the cooler housing 73 is in the form of a plate through which no fluid can pass. In particular, a sealing plate 81 is arranged above the third cooling fluid connection zone 25 of the machine housing 7 . The latter represents a sealing device which seals the third cooling fluid connection zone 25 in such a manner that no fluid can be exchanged between the machine module 2 and the cooler module 72 through this cooling fluid connection zone 25. Open air cooling of the electrical appliance 1 at one end with the cooler module 72 operates as follows: Cooling air is sucked into the first cooler housing area 74 from the outside via the inlet opening 77. The suction effect is once again produced by rotation of the rotor in the stator 4. Alternatively, this suction effect can be produced or assisted by a fan. No such fan is illustrated in FIGURE 4 but, for example this may be in the form of a radial fan arranged in the first edge section 14 of the machine housing 7. Alternatively, an axial fan can also be provided. A flow direction arrow 82 indicates the entry of the cooling air into the inlet opening 77. From the inlet opening 77, the cooling air initially flows through the first cooler housing area 74 as indicated by a flow direction arrow 83, and from there through the aperture opening 24 and the second cooling fluid connection zone 23 into the second edge section 15 of the machine housing 7, as indicated by a flow direction arrow 84. In FIGURE 4, the cooling air then flows from the right into the electric motor 3, and flows through the aperture openings and passages in the rotor on the one hand as well as the aperture openings 5 and the passages 6 in the stator 4 on the other hand, as described in conjunction with the cooling air flow for cooling in FIGURE 1. Since the cooling air cannot escape upward through the third cooling fluid connection zone 25, the cooling air flows completely through the electric motor 3 axially from right to left in FIGURE 4 as indicated by flow direction arrows 85, 86 and 87. This thus represents cooling of the electric motor 3 from one end. From the central section 13, the cooling air then flows into the first edge section 14 of the machine housing 7, and from there via the first cooling fluid connection zone 20 and the aperture opening 22 into the second cooler housing area 75 of the cooler housing 73, as indicated by a flow direction arrow 88. The heated cooling air then flows from the aperture opening 22 through the continuously widening second cooler housing area 75 to the junction between the separating wall sections 79, 80 as indicated by a flow direction arrow 89, to the outlet opening 78, and from there out of the cooler housing 73. FIGURE 5 shows the electrical appliance 1 of a fourth variant of a cooler module 90, which can be mounted on the machine module 2. The design of the cooler module 90 will be described in the following text only where it differs from the design of the cooler module 41 shown in FIGURE 2. Components which correspond to those which have already been explained with reference to FIGURES 1 to 4, have the same reference numbers and will not be discussed in detail again. A cooler housing 91 of the cooler module 90 does not have the aperture opening 27, but is closed by a sealing plate 92 . The latter therefore represents a sealing device which seals the third cooling fluid connection zone 25 of the machine housing 7, so that no fluid can be exchanged between the machine module 2 and the cooler module 90 through the third cooling fluid connection zone 25. A closed cooling air circuit from one end for primary cooling air has the following profile in the cooler module 90: The cooling air profile in the machine housing 7 in the embodiment of the electrical appliance 1 as shown in FIGURE 5 corresponds to that in the embodiment shown in FIGURE 4, as indicated by the flow direction arrows 85, 86 and 87. Heated cooling air then enters the edge section 43 on the left in FIGURE 5, of the cooler housing 91 via the first cooling fluid connection zone 20 and the aperture opening 22. Heat is initially exchanged between the heated primary cooling air and the secondary cooling air in the edge section 43, which secondary cooling air flows through the cooling air tubes 51 of the air heat exchanger 52 of the cooler module 90. A flow direction arrow 93 indicates the heated cooling air entering the edge section 43. The cooling air which has been cooled down then bypasses the supporting wall 48 as indicated by a flow direction arrow 94, flows through the second cooler housing section 45, as indicated by a flow direction arrow 95, and then bypasses the supporting wall 50 as indicated by a flow direction arrow 96, with the cooling air that has now been cooled down flowing into the edge section 44 on the right in FIGURE 5. The cooling air that has been cooled down therefore then once again flows through the aperture opening 24 and the second cooling fluid connection zone 23 into the machine housing 7, thus closing the primary air circuit. FIGURE 6 shows a further variant of a cooler module 97 for mounting on the machine module 2 . Components which correspond to those which have already been explained above with reference to FIGURES 1 to 5 have the same reference numbers and will not be discussed in detail again. An air-water heat exchanger 99 is arranged in a cooler housing 98 of the cooler module 97, centrally and parallel to the end wall of the cooler housing 91, as shown on the left and right in FIGURE 6. The air-water heat exchanger 99 has two laminate modules 100, 101. Air flows through the laminates of the laminate modules 100, 101. This cooling air itself exchanges heat with the cooling water which is flowing through cooling water tubes which are accommodated in the laminate modules 100, 101. These modules have laminates through which cooling water flows corresponding to the laminates in the water heat exchanger 59 in the embodiment shown in FIGURE 3. The main extent plane of the laminates of the water heat exchanger 99 in this case corresponds to that of the water heat exchanger 59. In principle, the embodiment of the water heat exchanger 59 shown in FIGURE 3 can also be used instead of the water heat exchanger 99. The water heat exchanger 99 subdivides the interior of the cooler housing 98 into a first cooler housing section 102, shown on the left in FIGURE 6, and a second cooler housing section 103, shown on the right in FIGURE 6. The first cooler housing section 102 is connected for fluid flow purposes via the aperture opening 22 to the first cooling fluid connection zone 20 of the machine housing 7. The second cooler housing section 103 is connected for fluid flow purposes via the aperture opening 24 to the second cooling fluid connection zone 22 of the machine housing 7. A fluid connection is provided between the two cooler housing sections 102, 103 via the water heat exchanger 99. At the bottom, the cooler housing 91 of the cooler module 90 has a sealing plate 104 between the aperture openings 22 and 24. The latter represented a sealing device, which seals the third cooling fluid connection zone 25 of the machine housing 7, such that no fluid can be exchanged between the machine module 2 and the cooler module 97 through the third cooling fluid connection zone 25. Air-water circuit cooling from one end is provided with the cooler module 97 for the electrical appliance 1 shown in FIGURE 6 as follows: The air flow in the machine housing 7 in the embodiment shown in FIGURE 6 corresponds to that in the embodiment shown in FIGURES 4 and 5, as indicated by the flow direction arrows 85, 86 and 87. The heated cooling air enters the first cooler housing section 102 from the first edge section 14 via the first cooling fluid connection zone 20 and the aperture opening 22, as indicated by a flow direction arrow 105. From the first cooler housing section 102, the cooling air passes through the water heat exchanger 99, during which process it is cooled down by exchanging heat with the cooling air and the water, which is flowing through the laminate modules 100, 101. The cooling air that has been cooled down then flows from the second cooler housing section 103 through the aperture opening 24 and the second cooling fluid connection zone 23 into the second edge section 15 of the machine housing 7. This completes the cooling circuit for the primary cooling air. The various variants of cooler modules 19, 41, 58, 72, 90, 97 represent a set, in which case, optionally a cooler module 19, 41, 58, 72, 90, 97 forming this set can be mounted on the machine module 2, whose design on the housing side is always the same, depending on the cooling requirements and the existing circumstances. Wherever an aperture opening for connection to the outside is provided for the primary cooling air guides as described above, this can be designed such that it is protected against the ingress of water and dust. As an alternative to or in addition to the aperture openings 18 in the webs 16, a tangential flow of cooling fluid between the stator casing 12 and the housing wall 17 can be achieved by the webs 16 being shaped such that the stator casing 12 rests on it only in places, so that intermediate spaces are created between the stator casing 12 and the webs 16, allowing a tangential flow through them. WE CLAIM : 1. A set comprising a plurality of cooler modules (19;41;58;72;90;97) and a machine housing (7), wherein the machine housing (7) can be assembled with each of the cooler modules (19;41;58;72;90;97), wherein each cooler module (19;41;58;72;90;97) comprises a cooler housing (21;42;62;73;91;98), which can be connected for fluid flow purposes to the interior of the machine housing (7) via - a first cooling fluid connection zone (20) in a housing wall (17) of a machine housing (7), and; - at least one second cooling fluid connection zone (23) in the housing wall (17) of the machine housing (7); wherein the interior of the machine housing (7) can be connected for fluid flow purposes, in a section of the housing wall (17) which faces the cooler housing (21;42;62;73;91;98) via at least one third cooling fluid connection zone (25) by means of at least one cooling fluid aperture opening (26) to the interior of the cooler housing (21;42;62;73;91;98), wherein the machine housing (7) can hold an electrical machine (3) in such a manner that an axial cooling fluid flow is produced between a stator casing (12) of the electrical machine (3) and the housing wall (17) and a cooling fluid flow which surrounds the stator casing (12) is produced between the stator casing (12) and the housing wall (17), wherein the housing wall (17) has webs (16) which run internally parallel to the stator axis and serve for resting on the stator casing (12) at least in places and which release aperture openings (18) for circulating cooling fluid flow when the stator (4) is fitted, wherein the plurality of cooler modules (19;41;58;72;90;97) comprise at least two cooler modules (19;41;58;72;90;97) from the following cooler module variants: - a first cooler module variant (19) - having a first cooler housing area (28) which is connected for fluid flow purposes via at least one inlet opening (31,32) to the surrounding area, and is connected for fluid flow purposes via corresponding aperture openings (22,24) to the first (20) and to the second (23) cooling fluid connection zone, - having a second cooler housing area (29) which is separated in a fluid- tight manner from the first cooler housing area (28), is connected for fluid flow purposes via at least one aperture opening (27) to the third cooling fluid connection zone (25) and is connected for fluid flow purposes via an outlet opening (33) to the surrounding area; - a second cooler module variant (41;58) - having a first cooler housing section (43,44) which is connected for fluid flow purposes via corresponding aperture openings (22,24) to the first (20) and to the second (23) cooling fluid connection zone; - having a second cooler housing section (45;67) which is connected for fluid flow purposes to t he first cooler housing section (43,44) and is connected for fluid flow purposes via at least one aperture opening (27) to the third cooling fluid connection zone (25); - having a heat exchanger (52;59), which makes thermal contact with the two cooler housing sections (43,44); - a third cooler module variant (72); - having a first cooler housing area (74) which is connected for fluid flow purposes via at least one inlet opening (77) to the surrounding area, and is connected for fluid flow purposes via at least one aperture opening (24) to the second cooling fluid connection zone (23); - having a second cooling housing area (75) which is separated in a fluid- tight manner from the first cooling housing area (74) is connected for fluid flow purposes via at least one aperture opening (22) to the first cooling fluid connection zone (20) and is connected for fluid flow purposes via at least one outlet opening (78) to the surrounding area; - having a sealing device (81) which seals the third cooling fluid connection zone (25) such that no cooling fluid can be exchanged between the machine housing (7) and the cooler module (72); - a fourth cooler module variant (90;97); - Having a fist cooler housing area (43; 102) which is connected for fluid flow purposes via at least one aperture opening (22) to the first cooling fluid connection zone (20); - Having a second cooler housing section (44; 103) which is connected for fluid flow purposes to the first cooler housing section (43; 102) and is connected for fluid flow purposes via at least one aperture opening (24) to the second cooling fluid connection zone (23); - having a heat exchanger (52;99) which makes thermal contact with the two cooler housing sections (43;44;102;103); - having a sealing device (92; 104), which seals the third cooling fluid connection zone (25) such that no cooling fluid can be exchanged between the machine housing (7) and the cooler module (90;97) through the third cooling fluid connection zone (25). 2. The set as claimed in claim 1, wherein the aperture openings (18) are formed in the webs (16). 3. The set as claimed in one of Claims 1 to 2, wherein at least one axial or radial fan in the cooler housing (21;42;62;73;91;98) and/or in the machine housing is provided (7) in order to preset an air flow direction. 4. The set as claimed in claim 1 wherein at least one cooler module (41;90) of the second and fourth cooler module variant is in each case provided with the cooler housing (91) of the fourth cooler module variant (90) being identical to the cooler housing (42) of the second cooler module variant (41), apart from the additional sealing device (92). 5. The set as claimed in claim 1 or 4, wherein the heat exchanger (52) for the second (41) or fourth (90) cooler module variant is a gas-gas heat exchanger, in particular an air-air heat exchanger. 6. The set as claimed in claim 1 or 4 wherein the heat exchanger (52;99) for the second (58) or fourth (97) cooler module variant is a gas-liquid heat exchanger, in particular an air-water heat exchanger. ABSTRACT A SET COMPRISING A PLURALITY OF COOLER MODULES FOR ASSEMBLY WITH A MACHINE MODULE The invention relates to an electric unit (1) which comprises a machine module (2) provided with an electric machine (3) comprising a stator (4) and a rotor. A machine housing (7) of the machine module (2) receives the electric machine (3). A cooling module (19) comprises a cooling housing (21), which is fluidically connected to the machine housing (7) by means of a first cooling fluid connection area (20) in a housing wall (17) of the machine housing (7) and to at least one second cooling fluid connection area (23) in the housing wall (17) of the machine housing (7). The inside of the machine housing (7) can be fluidically connected to the inside of the cooling housing (21) in one section of the housing wall (17), which is oriented towards the cooling housing (21), by means of at least one third cooling fluid connection area (25) comprising at least one cooling fluid through-opening (26). Various cooling module variants can use said third cooling fluid connection area (25) when other cooling module variants, which can be used in exchange with the cooling module (19) in the machine module (2), do not use the third cooling fluid connection area (25). As a result, an electric unit (1), a machine module (2) therefore and a set comprising a plurality of different cooling modules, which can meet altered cooling requirements having reduced structural and constructural costs, can be produced.

Full Text

Description
Title of the invention: Set comprising a plurality of cooler
modules for assembly with a machine module
Text: The invention relates to a set comprising a plurality of
cooler modules, for assembly with a machine module.
An electrical appliance having a machine module and a cooler
module is known from JP 60-219 939 A. There, the electrical
appliance has a heat exchanger through which a flow passes
along a zigzag path, starting from the first cooling fluid
connection zone, to the second cooling fluid connection zone.
The cooling of known electrical appliances such as these in
each case is matched to the machine module that is used. As
soon as it is found that a specific cooling technique is no
longer adequate for the machine module, the cooling for the
electrical appliance must be completely redesigned.
Further electrical appliances are known from JP 57-040344 A,
JP 61-285039 A and WO 01/17094 Al.
One object of the present invention is to provide a choice of
cooling variants matched to the particular application, for a
machine module, without having to make any design changes to
the machine module for this purpose.
According to the invention, this object is achieved by a set
comprising a plurality of cooler modules as claimed in claim 1.
The first cooler module variant allows open air cooling from
both ends of the electrical machine. The second cooler module
variant allows closed air cooling with a heat exchanger from
both ends of the electrical machine. The third cooler module
variant allows open air cooling flowing longitudinally through

the electrical machine. The fourth cooler module variant allows
closed air cooling flowing longitudinally through the

electrical machine, with a heat exchanger. Depending on the
ingress protection class of the electrical machine, it is then
possible, for example to choose an open or closed type of
cooling. A closed electrical machine can be operated with an
air-air heat exchanger or with an air-water heat exchanger. The
maximum cooling power based on VDE 0530 and thus the maximum
machine power are achieved with an open machine with forced-
draft ventilation and with air-water cooling. With a
correspondingly reduced power, an air-air cooled machine offers
the advantage of a closed type in combination with air cooling.
Electrical machines are manufactured with different numbers of
poles and are therefore designed for different rotation speeds.
These machines can then the operated with a power supply system
with a fixed rotation speed or from a converter with a variable
rotation speed. Depending on the number of pole pairs and when
converters are used for operation, it may also be advantageous,
depending on the desired rotation-speed range, to cool the
machine with the air flow from both ends, or from one end. In
this case, the air resistance of the cooler module also plays
an important role. Depending on the cooling type and number of
pole pairs and the rotation speed it is possible according to
the invention to choose the most efficient cooling variant with
one and the same machine housing. Cooler modules with cooling
air guides which do not require the third cooling fluid
connection zone for the machine housing, seal them simply with
the respective sealing device, so that the cooling air flows
solely through the two remaining cooling fluid connection zones
to the machine housing.
A refinement of cooler module variants as claimed in claim 2 is
particularly advantageous for cost-effective production of
these cooler module variants. Alternatively it is possible to
provide a tube connection in order to supply cooling air to the
machine housing. When air is supplied at one end, that is to
say it flows longitudinally through the electrical machine,

the third cooling fluid connection zone is closed with the aid
of the sealing device. In the case of air cooling of

both ends, the air is supplied via tube connections to the
first and second cooling fluid connection zone, and the air is
carried away via the tube connection to the third cooling fluid
connection zone.
Heat exchangers as claimed in claims 3 and 4 are adequate for
many cooling requirements, even relatively demanding cooling
requirements.
The design of the machine housing of the machine module with
three cooling fluid connection zones makes it possible to
produce different variants of the cooling air guidance in the
machine housing. These different cooling air guidance variants
can then be combined with appropriate cooler modules, so that
it is possible to take account of individual cooling
requirements. The electrical appliance according to claim 5 can
thus be equipped with different cooling techniques for the
respective cooler module, without any need to make any physical
changes for this purpose to the machine module, in particular
without having to make any physical changes to the machine
housing. By way of example, the following cooling techniques
can be implemented with the same machine housing, just by
adaptation of the cooler module: open air cooling from both
ends of the electrical machine, closed air cooling with an air-
air heat exchanger from both ends of the electrical machine,
closed air cooling with an air-water heat exchanger from both
ends of the electrical machine, open air cooling flowing
longitudinally through the electrical machine, closed air
cooling flowing longitudinally through the electrical machine
with an air-air heat exchanger, closed air cooling flowing
longitudinally through the electrical machine with an air-water
heat exchanger. The cooler module either has only the function
of cooling fluid guidance or includes active cooling elements
such as heat exchangers. A standardized machine housing can be
used for all of these cooling techniques. An electric motor, or

alternatively a generator, may be used as the electrical
machine.
A machine housing as claimed in claim 6 provides effective
stator cooling.

A machine housing as claimed in claim 7 allows cooling fluid guidance in which
cooling fluid is not only supplied to or carried away from the ends of the
machine, but is also passed via a central section of the machine housing. The
cooling fluid can be supplied to this central section of the machine housing via
the circulating and tangential cooling fluid flow component. This allows on the
one hand cooling from both ends, and as well as cooling which flows through the
machine from one end, on the other hand to be provided with one and the same
machine housing.
Webs as claimed in claim 8 offer a simple design capability to ensure a
circulating cooling fluid flow.
t
Aperture openings in the webs as claimed in claim 9 result in defined tangential
cooling fluid guidance.

Air as the cooling fluid as claimed in claim 10 represents the simplest variant for
cooling within the machine housing. Alternatively, it is also possible to use a
different cooling fluid, in particular a cooling gas other than air. In principle, it is
also possible to use a cooling liquid.

A fan as claimed in claim 11 is advantageous when the rotor movement itself
does not preset or does not adequately preset the desired flow direction of the
cooling fluid.

Exemplary embodiments of the invention will be explained in more detail in the
following text with reference to the accompanying drawing, in which:
Figure 1 shows a perspective view of a detail of an electrical appliance having a
machined module and a first cooler module variant, which represents part of a
set comprising a plurality of cooler modules for assembly

FIGURE 2 shows a perspective view of a detail of a further
electrical appliance having the machine module as
shown in FIGURE 1 and of a second cooler module
variant of the cooler module set, which has an air-
air heat exchanger;
FIGURES 3-6 show perspective views of a detail of the
machine module as shown in FIGURE 1, with further
cooler module variants, and
FIGURE 7 shows a perspective, enlarged view, of a detail of a
machine housing for the machine module.

FIGURE 1 shows a perspective view of a detail of a drive
appliance 1 as an example of an electrical appliance. This is a
machine with a cooling circuit. The electrical appliance 1 has
a motor module 2 illustrated at the bottom of FIGURE 1, as an
example of a machine module. This has an electric motor 3 as an
example of an electrical machine of which only a stator 4 to be
precise the right-hand cutaway half of it, is illustrated in
FIGURE 1. The stator 4 is in the form of a laminated core. As
is known per se, the stator 4 has a plurality of aperture
openings 5 through which fluid can flow radially through the
stator 4. The rotor, which is not illustrated, also has
corresponding aperture openings, which are known per se.
Furthermore both the stator 4 and the rotor have passages 6
which run both through the stator 4 and through the rotor in
the axial direction and through which fluid can likewise flow.
The electric motor 3 is accommodated in a machine or motor
housing 7. The drawing shows only a vertically longitudinally
sectioned rear half of this housing. The machine housing 7 has
a first end wall 8, on the left in the drawing, and a second
end wall 9 on the right in the drawing. Adjacent to the first
end wall 8 and at a distance from it, the machine housing 7 has
a first intermediate wall 10, in the left in the drawing.
Adjacent to the second end wall 9, the machine housing 7 has a
second intermediate wall 11, on the right in Figure 7. When the
electric motor is assembled, an end shield which is not
illustrated, in each case seals the electric motor 3 from the
end walls 8, 9, such that it is not possible for any fluid to
flow into or out of the machine housing 7 at the end, that is
to say at the two ends of the electric motor 3. When the
electric motor 3 is assembled, a casing wall 12 of the stator 4
also rests on the intermediate walls 10, 11. The stator casing
is sealed on the housing walls via guide walls, which are not
illustrated. When the electric motor 3 is assembled, the
machine housing 7 is thus subdivided into an axial central
section 13

between the two intermediate walls 10, 11 into a first edge
section 14 which is shown on the left in the drawing

between the first end wall 8 and the first intermediate wall
10, and into a second edge section 15 which is shown on the
right in FIGURE 7 between the second intermediate wall 11 and
the second end wall 9.
In the area of the central section 13, the machine housing 7
has an octagonal cross section at right angles to its
longitudinal axis. In the central section 13, the casing wall
12 of the stator 4 rests on the machine housing 7 via webs 16
which run axially between the intermediate walls 10, 11 and are
firmly connected to a housing casing wall 17 of the machine
housing 7. The external circumference of the stator 4 is fixed
to the webs 16. The webs 16 have fluid aperture openings 18 at
right angles to their extent direction and parallel to the
adjacent section of the housing wall 17. In the illustrated
exemplary embodiment, six aperture openings 18 are provided for
each web 16.
In FIGURE 1, a cooler module 19 of the electrical appliance 1
is arranged above the machine housing 7 and is firmly connected
to the machine module 2. The interior of a cooler housing 21 of
the cooler module 19 is connected for fluid flow purposes to
the first edge section 14 of the machine housing 7 via a first
cooling fluid connection zone 20 in an upper section in the
drawing, of the housing wall 17 which faces the cooler module
19 and is formed at the cooler end by a cooling fluid supply
opening. For this purpose, the cooler housing 21 has an
aperture opening 22 in the bottom face in FIGURE 1, which is
aligned with the first cooling fluid connection zone 20 of the
machine housing 7. Furthermore, the machine housing 7 has a
second cooling connection zone 23, which is likewise formed on
the motor side by a cooling fluid aperture opening in that
housing wall section of the machine housing 7 which faces the
cooler module 19. The second edge section 15 of the machine
housing 7 is connected for fluid flow purposes to the cooler
housing 21 via the second cooling fluid connection zone 23.

For this purpose, the cooler housing 21 has a further aperture
opening 24, on the bottom face on the right in FIGURE 1.
Furthermore, the machine housing 7 has a third

cooling fluid connection zone 25 in the housing wall section
which faces the cooler module 19. This is located between the
first two cooling fluid connection zones 20, 23. The third
cooling fluid connection zone is formed on the motor side in
the upper wall section in the drawing, that is to say the wall
section facing the cooler housing 21, of the central section 13
which has an octagonal cross section, of the machine housing 7
and is subdivided into a plurality, in the illustrated
exemplary embodiment into a total of 18, square aperture
openings 2 6 arranged in a grid.
The central section 13 is connected for fluid flow purposes to
the interior of the cooler housing 21 via the third cooling
fluid connection zone 25. For this purpose, on the bottom face,
the cooler housing 21 has a central aperture opening 27 between
the aperture openings 22 and 24.
The interior of the cooler housing 21 is subdivided into a
first cooler housing area 28, that is to say the upper cooling
housing area in FIGURE 1 and into a second cooler housing area
29 which is illustrated centrally at the bottom in FIGURE 1.
The two cooling housing areas 28, 29 are separated from one
another in a fluid-tight manner by a partition wall 30 in the
form of a platform. The latter extends from a bottom
intermediate web of the cooler housing 21 which is arranged
between the aperture openings 22 and 27, to a further bottom
intermediate web of the cooler housing 21 between the aperture
openings 27 and 24. The first cooler housing area 28 is
connected for fluid flow purposes on the one hand by the
aperture openings 22 and 24 to the first cooling fluid
connection zone 20, and on the other hand to the second cooling
fluid connection zone 23. The second cooler housing area 29 is
connected for fluid flow purposes via the aperture opening 27
to the third cooling fluid connection zone 25. The first cooler
housing area 28 is connected for fluid flow purposes to the
area surrounding the cooler module 19 via inlet openings 31, 32

which are arranged opposite one another at the ends. The second
cooler housing area 29 is connected to the area surrounding the
cooler module 19 via a bottom outlet opening 33. The outlet
opening 33 is aligned with

a cutout 34 in the housing section of the machine housing 7
facing the cooler module 19, with this resulting from the
octagonal cross section of the central section 13.
Open air cooling of the electric motor 3 at both ends in the
electrical appliance 1, as shown in FIGURE 1, operates as
follows:
Air is sucked in via the inlet openings 31, 32 into the first
cooler housing area 28 of the cooler housing 21, as indicated
by the flow direction arrows 35, 36 in FIGURE 1. A suction
effect which results in this inward suction, is created by the
rotation of the rotor on the electric motor 3 in the stator 4.
The air that is sucked in passes through the first cooling
fluid connection zone 20 and the second cooling fluid
connection zone 23, that is to say on the one hand it enters
the first edge section 14 of the machine housing 7 via the
aperture openings 22 and 20, and on the other hand enters the
second edge section 15 of the machine housing 7 via the
aperture openings 24 and 23. As indicated by the direction of
the flow arrows 37, 38, the cooling air enters the central
section 13 of the machine housing 7 from there. In this case,
the air flows from both ends of the electric motor 3 through
the corresponding aperture openings and passages in the rotor
and through the aperture openings 5 and the passages 6 in the
stator 4. This therefore represents double-ended cooling of the
electric motor 3. Furthermore, for example, the cooling air
which emerges from the stator 4 passes over the outside of the
casing wall 12 of the stator 4. The casing wall 12 is separated
from the housing wall 17 by the webs 16, so that fluid can flow
between the casing wall 12 and the housing wall 17. This
provides efficient air-cooling for the rotor and the stator 4.
In the central section 13, the cooling air can flow through the
aperture openings 18 in the webs 16 to the aperture openings 26
in the third cooling fluid connection zone 25, as indicated by

the flow direction arrows 39,
the webs 16 therefore allow
cooling air flow between the
wall 17. The cooling air which

40. The aperture openings 18 in
for circulating and tangential
casing wall 12 and the housing
transports the waste heat away

enters the second cooling housing area 29 from the third
cooling fluid connection zone 25 and flows out to the exterior
again from the outlet opening 33, from this area, via the
cutout 34.
FIGURE 2 shows the machine module 2 with a second variant of a
cooler module 41. The latter will be described in the following
text only where it differs from the cooler module 19.
Components which correspond to those which have already been
explained above with reference to FIGURE 1 have the same
reference numbers and will not be discussed in detail again.
A cooler housing 42 of the cooler module 41 is subdivided into
a first cooler housing section with two edge sections 43, 44 on
the one hand, and the second cooler housing section 45 on the
other hand. The edge sections 43, 44 of the cooler housing 42
are arranged above the edge sections 14, 15 of the machine
housing 7 in FIGURE 2. The edge section 43 is connected for
fluid flow purposes via the aperture opening 22 to the aperture
opening in the first cooling fluid connection zone 20 in the
machine housing 7. The edge section 44 is connected for fluid
flow purposes via the aperture opening 24 to the aperture
opening in the second cooling fluid connection zone 23 of the
machine housing 7. The second cooler housing section 45 is
connected for fluid flow purposes via the aperture opening 27
to the aperture openings 26 in the third cooling fluid
connection zone 25 of the machine housing 7.
Three supporting walls 48, 49, 50 are arranged parallel to end
walls 46, 47 of the cooler housing 42, which are shown on the
left and right in FIGURE 2 in the interior of the cooler
housing 42. The first supporting wall 48, which is shown on the
left in FIGURE 2, is mounted at the bottom on a supporting web
of the cooler housing 42, which is arranged between the
aperture openings 22 and 27. The supporting wall 48 separates
the edge section 43, on the left in FIGURE 2, from the second

cooler housing section 45. This separation is not complete,
since the supporting wall 48 does not extend

as far as the housing wall of the cooler housing 42 shown at
the top in FIGURE 2. The second supporting wall 4 9 is mounted
on the wall of the cooler housing 42 shown at the top in
FIGURE 2, in the second cooler housing section 45. The second
supporting wall 49 does not extend as far as the bottom of the
cooler housing 42, so that the supporting wall 49 in the second
cooler housing section 45 does not represent a barrier for
cooling fluid. The third supporting wall 50 is mounted on a
bottom supporting web of the cooler housing 42 which is
arranged between the aperture openings 27 and 24, and its
extend corresponds to that of the first supporting wall 48.
Like the first supporting wall 48, the third supporting wall 50
represents a subdivision, which can be overcome for cooling
fluid between the second cooler housing section 45 and the edge
section 44 on the right in FIGURE 2.
Cooling air tubes 51 for secondary cooling air are supported by
the end walls 46, 47 and the supporting walls 48 to 50 and
passed through the cooler housing 42 parallel to the axis of
the electric motor 3. In the exemplary embodiment shown in
FIGURE 2 there are a total of eighty cooling air tubes 51.
These form an air-air heat exchanger 52.
Closed air-circuit cooling is provided at both ends for the
electrical appliance 1 shown in FIGURE 2 as follows:
Primary cooling air enters the machine housing 7 via the first
cooling fluid connection zone 20 and the second cooling fluid
connection zone 23, as indicated by flow direction arrows 53,
54 in FIGURE 2 . The further cooling air flow in the machine
housing 7 in the electrical appliance 1 as shown in FIGURE 2
corresponds to the cooling air flow for the cooling of the
electrical appliance 1 shown in FIGURE 1 as indicated by the
flow direction arrows 39, 40. After passing through the third
cooling fluid connection zone 25, the cooling air which
transports the heat away enters the second cooler housing

section 45 of the cooler housing 42, as indicated by flow
direction arrows 55. In the second cooler housing section 45
and in the two edge sections 43, 44 of the first cooler housing

section of the cooler housing 42, heat is now exchanged from
the heat-emitting primary cooling air to the heat-receiving
secondary cooling air which flows through cooling air tubes 51.
The primary cooling air in this case bypasses the separating
walls 48, 50 and once again flows in the direction of the first
cooling fluid connection zone 20 on the one hand, and the
second cooling fluid connection zone 23 on the other hand, as
indicated by flow direction arrows 56, 57. This completes the
cooling circuit of the primary cooling air. The flow direction
of this cooling circuit results from the suction effect of the
electric motor 3.
A further variant of a cooler module 58 will be described in
the following text with reference to FIGURE 3. The description
covers only the differences between the cooler module 58 and
the cooler module 41 shown in FIGURE 2. Components which
correspond to those which have already been explained above
with reference to FIGURES 1 and 2 have the same reference
numbers and will not be discussed in detail again.
Instead of an air-air heat exchanger, the cooler module 58 has
an air-water heat exchanger 59. This has two laminate modules
60, 61, which are illustrated schematically in FIGURE 3 as
blocks with a rectangular cross section. As is known, for
example, from motor vehicle radiators, the cooling laminates of
the laminate modules 60, 61 through which cooling water flows
are in the form of flat structures, which are all aligned
essentially parallel to the main extent plane. This main extent
plane is at the same time at right angles to the bottom of a
cooler housing 62 of the cooler module 58, and on the other
hand is at right angles to end walls 63, 64 of the cooler
housing 62 with these being shown on the left and right in
FIGURE 3. This alignment of the laminate results in the flows
of the primary cooling air being impeded as little as possible.
The water heat exchanger 59 is supported by a supporting wall
65 in the form of a platform. A contact wall 66

of the supporting wall 55 on which the water heat exchanger 59
rests is designed such that air can pass through it, that is to
say it has aperture openings for the primary cooling air.

These aperture openings distinguish the supporting wall 65 from
the separating wall 30 in the cooler housing 21 of the cooler
module 19 shown in FIGURE 1. Otherwise, the form and the
installation of the supporting wall 65 correspond to those for
the separating wall 30. The supporting wall 65 separates a
first cooler housing section of the cooler housing 62 with the
edge sections 43, 44 from the second, central cooler housing
section 67, which is bounded at the top by the supporting wall
65 in FIGURE 3.
Closed air-water cooling at both ends for the cooler module
variant shown in FIGURE 3 operates as follows:
The primary cooling air flow in the machine housing 7
corresponds to that which has been described in conjunction
with the cooler module 41 shown in FIGURE 2. The heated cooling
air enters the second cooler housing section 67 of the cooler
housing 62 from the third cooling fluid connection zone 25,
from where it enters the laminate modules 60, 61 through the
contact wall 66 as indicated by flow direction arrows 68, 69.
In the laminate modules 60, 61, the cooling air emits its heat
to the cooling water of the water heat exchanger 59 as it flows
through the laminates. From the laminate modules 60, 61 the
cooling air that has been cooled down flows into the edge
sections 43, 44 of the cooler housing 62 from where it once
again flows in the direction of the aperture openings 22, 24 as
indicated by flow direction arrows 70, 71.
A third variant of a cooler module 72 will be described in the
following text with reference to FIGURE 4 in which case this
third variant can be mounted on the machine module 2 in order
to complete an electrical appliance 1 instead of the cooler
modules 19, 41 and 58. Components of the cooler module 72 which
correspond to those which have already been explained above in
conjunction with FIGURES 1 to 3 have the same reference numbers
and will not be discussed in detail again. A cooler housing 73

of the cooler module 72 is subdivided into a first, bottom
cooler housing area 74 and a second, cooler

housing area 75, which is essentially arranged above it. The
two cooler housing areas 74, 75 are separated from one another
in a fluid-tight manner via a separating wall 7 6 within the
cooler housing 73.
The first cooler housing area 74 is connected for fluid flow
purposes to the area surrounding the cooler module 72 via an
inlet opening 77. The size and arrangement of the inlet
arrangement 77 correspond to those of the outlet opening 33 of
the cooler module 19 shown in FIGURE 1. The first cooler
housing area 74 is connected for fluid flow purposes to the
second cooling fluid connection zone 23 via the aperture
opening 24.
A section of the second cooler housing area 75 on the left in
FIGURE 4 is connected for fluid flow purposes to the first
cooling fluid connection zone 20 of the machine housing 7 via
the aperture opening 22. The second cooler housing area 75 is
connected to the area surrounding the cooler module 72 via an
outlet opening 78. The size and arrangement of the outlet
opening 78 correspond to those of the inlet opening 32 of the
cooler housing 21 shown in FIGURE 1.
The separating wall 76 has a first separating wall section 79,
which is mounted on a bottom supporting web of the cooler
housing 73 between the aperture opening 22 and the inlet
opening 77, and rises steeply from the bottom, so that the
second cooler housing area 75 initially widens continuously,
starting from the aperture opening 22. A second separating wall
section 80 of the separating wall 76 is adjacent to the first
separating wall section 79. This is arranged such that it falls
away slightly in the cooler housing 73 so that the second
cooler housing area 75 widens continuously towards the outlet
opening 78, starting from the connection between the two
separating wall sections 79, 80.

Apart from the bottom openings 22, 24 and 77, the bottom of the
cooler housing 73 is in the form of a plate through which no
fluid can pass. In particular, a sealing plate 81 is arranged
above the third cooling fluid connection zone 25 of the machine

housing 7 . The latter represents a sealing device which seals
the third cooling fluid connection zone 25 in such a manner
that no fluid can be exchanged between the machine module 2 and
the cooler module 72 through this cooling fluid connection zone
25.
Open air cooling of the electrical appliance 1 at one end with
the cooler module 72 operates as follows:
Cooling air is sucked into the first cooler housing area 74
from the outside via the inlet opening 77. The suction effect
is once again produced by rotation of the rotor in the stator
4. Alternatively, this suction effect can be produced or
assisted by a fan. No such fan is illustrated in FIGURE 4 but,
for example this may be in the form of a radial fan arranged in
the first edge section 14 of the machine housing 7.
Alternatively, an axial fan can also be provided. A flow
direction arrow 82 indicates the entry of the cooling air into
the inlet opening 77. From the inlet opening 77, the cooling
air initially flows through the first cooler housing area 74 as
indicated by a flow direction arrow 83, and from there through
the aperture opening 24 and the second cooling fluid connection
zone 23 into the second edge section 15 of the machine housing
7, as indicated by a flow direction arrow 84. In FIGURE 4, the
cooling air then flows from the right into the electric motor
3, and flows through the aperture openings and passages in the
rotor on the one hand as well as the aperture openings 5 and
the passages 6 in the stator 4 on the other hand, as described
in conjunction with the cooling air flow for cooling in
FIGURE 1. Since the cooling air cannot escape upward through
the third cooling fluid connection zone 25, the cooling air
flows completely through the electric motor 3 axially from
right to left in FIGURE 4 as indicated by flow direction arrows
85, 86 and 87. This thus represents cooling of the electric
motor 3 from one end. From the central section 13, the cooling
air then flows into the first edge section 14 of the machine

housing 7, and from there via the first cooling fluid
connection zone

20 and the aperture opening 22 into the second cooler housing
area 75 of the cooler housing 73, as indicated by a flow
direction arrow 88. The heated cooling air then flows from the
aperture opening 22 through the continuously widening second
cooler housing area 75 to the junction between the separating
wall sections 79, 80 as indicated by a flow direction arrow 89,
to the outlet opening 78, and from there out of the cooler
housing 73.
FIGURE 5 shows the electrical appliance 1 of a fourth variant
of a cooler module 90, which can be mounted on the machine
module 2. The design of the cooler module 90 will be described
in the following text only where it differs from the design of
the cooler module 41 shown in FIGURE 2. Components which
correspond to those which have already been explained with
reference to FIGURES 1 to 4, have the same reference numbers
and will not be discussed in detail again. A cooler housing 91
of the cooler module 90 does not have the aperture opening 27,
but is closed by a sealing plate 92 . The latter therefore
represents a sealing device which seals the third cooling fluid
connection zone 25 of the machine housing 7, so that no fluid
can be exchanged between the machine module 2 and the cooler
module 90 through the third cooling fluid connection zone 25.
A closed cooling air circuit from one end for primary cooling
air has the following profile in the cooler module 90:
The cooling air profile in the machine housing 7 in the
embodiment of the electrical appliance 1 as shown in FIGURE 5
corresponds to that in the embodiment shown in FIGURE 4, as
indicated by the flow direction arrows 85, 86 and 87.
Heated cooling air then enters the edge section 43 on the left
in FIGURE 5, of the cooler housing 91 via the first cooling
fluid connection zone 20 and the aperture opening 22. Heat is

initially exchanged between the heated primary cooling air and
the secondary cooling air in the edge section 43, which

secondary cooling air flows through the cooling air tubes 51 of
the air heat exchanger 52 of the cooler module 90. A flow
direction arrow 93 indicates the heated cooling air entering
the edge section 43.
The cooling air which has been cooled down then bypasses the
supporting wall 48 as indicated by a flow direction arrow 94,
flows through the second cooler housing section 45, as
indicated by a flow direction arrow 95, and then bypasses the
supporting wall 50 as indicated by a flow direction arrow 96,
with the cooling air that has now been cooled down flowing into
the edge section 44 on the right in FIGURE 5. The cooling air
that has been cooled down therefore then once again flows
through the aperture opening 24 and the second cooling fluid
connection zone 23 into the machine housing 7, thus closing the
primary air circuit.
FIGURE 6 shows a further variant of a cooler module 97 for
mounting on the machine module 2 . Components which correspond
to those which have already been explained above with reference
to FIGURES 1 to 5 have the same reference numbers and will not
be discussed in detail again. An air-water heat exchanger 99 is
arranged in a cooler housing 98 of the cooler module 97,
centrally and parallel to the end wall of the cooler housing
91, as shown on the left and right in FIGURE 6. The air-water
heat exchanger 99 has two laminate modules 100, 101. Air flows
through the laminates of the laminate modules 100, 101. This
cooling air itself exchanges heat with the cooling water which
is flowing through cooling water tubes which are accommodated
in the laminate modules 100, 101. These modules have laminates
through which cooling water flows corresponding to the
laminates in the water heat exchanger 59 in the embodiment
shown in FIGURE 3. The main extent plane of the laminates of
the water heat exchanger 99 in this case corresponds to that of
the water heat exchanger 59. In principle, the embodiment of

the water heat exchanger 59 shown in FIGURE 3 can also be used
instead of the water heat exchanger 99.

The water heat exchanger 99 subdivides the interior of the
cooler housing 98 into a first cooler housing section 102,
shown on the left in FIGURE 6, and a second cooler housing
section 103, shown on the right in FIGURE 6. The first cooler
housing section 102 is connected for fluid flow purposes via
the aperture opening 22 to the first cooling fluid connection
zone 20 of the machine housing 7. The second cooler housing
section 103 is connected for fluid flow purposes via the
aperture opening 24 to the second cooling fluid connection zone
22 of the machine housing 7. A fluid connection is provided
between the two cooler housing sections 102, 103 via the water
heat exchanger 99.
At the bottom, the cooler housing 91 of the cooler module 90
has a sealing plate 104 between the aperture openings 22 and
24. The latter represented a sealing device, which seals the
third cooling fluid connection zone 25 of the machine housing
7, such that no fluid can be exchanged between the machine
module 2 and the cooler module 97 through the third cooling
fluid connection zone 25.
Air-water circuit cooling from one end is provided with the
cooler module 97 for the electrical appliance 1 shown in
FIGURE 6 as follows:
The air flow in the machine housing 7 in the embodiment shown
in FIGURE 6 corresponds to that in the embodiment shown in
FIGURES 4 and 5, as indicated by the flow direction arrows 85,
86 and 87. The heated cooling air enters the first cooler
housing section 102 from the first edge section 14 via the
first cooling fluid connection zone 20 and the aperture opening
22, as indicated by a flow direction arrow 105. From the first
cooler housing section 102, the cooling air passes through the
water heat exchanger 99, during which process it is cooled down
by exchanging heat with the cooling air and the water, which is
flowing through the laminate modules 100, 101. The cooling air

that has been cooled down then flows from the second cooler
housing section 103 through the aperture opening 24

and the second cooling fluid connection zone 23 into the second
edge section 15 of the machine housing 7. This completes the
cooling circuit for the primary cooling air.
The various variants of cooler modules 19, 41, 58, 72, 90, 97
represent a set, in which case, optionally a cooler module 19,
41, 58, 72, 90, 97 forming this set can be mounted on the
machine module 2, whose design on the housing side is always
the same, depending on the cooling requirements and the
existing circumstances.
Wherever an aperture opening for connection to the outside is
provided for the primary cooling air guides as described above,
this can be designed such that it is protected against the
ingress of water and dust.
As an alternative to or in addition to the aperture openings 18
in the webs 16, a tangential flow of cooling fluid between the
stator casing 12 and the housing wall 17 can be achieved by the
webs 16 being shaped such that the stator casing 12 rests on it
only in places, so that intermediate spaces are created between
the stator casing 12 and the webs 16, allowing a tangential
flow through them.

WE CLAIM :
1. A set comprising a plurality of cooler modules (19;41;58;72;90;97) and a
machine housing (7), wherein the machine housing (7) can be assembled
with each of the cooler modules (19;41;58;72;90;97), wherein each
cooler module (19;41;58;72;90;97) comprises a cooler housing
(21;42;62;73;91;98), which can be connected for fluid flow purposes to
the interior of the machine housing (7) via
- a first cooling fluid connection zone (20) in a housing wall (17) of a
machine housing (7), and;
- at least one second cooling fluid connection zone (23) in the housing wall
(17) of the machine housing (7);
wherein the interior of the machine housing (7) can be connected for fluid
flow purposes, in a section of the housing wall (17) which faces the cooler
housing (21;42;62;73;91;98) via at least one third cooling fluid
connection zone (25) by means of at least one cooling fluid aperture
opening (26) to the interior of the cooler housing (21;42;62;73;91;98),
wherein the machine housing (7) can hold an electrical machine (3) in
such a manner that an axial cooling fluid flow is produced between a
stator casing (12) of the electrical machine (3) and the housing wall (17)
and a cooling fluid flow which surrounds the stator casing (12) is
produced between the stator casing (12) and the housing wall (17),
wherein the housing wall (17) has webs (16) which run internally parallel
to the stator axis and serve for resting on the stator casing (12) at least in
places and which release aperture openings (18) for circulating cooling
fluid flow when the stator (4) is fitted, wherein the plurality of cooler
modules (19;41;58;72;90;97) comprise at least two cooler modules
(19;41;58;72;90;97) from the following cooler module variants:

- a first cooler module variant (19)
- having a first cooler housing area (28) which is connected for fluid flow
purposes via at least one inlet opening (31,32) to the surrounding area,
and is connected for fluid flow purposes via corresponding aperture
openings (22,24) to the first (20) and to the second (23) cooling fluid
connection zone,
- having a second cooler housing area (29) which is separated in a fluid-
tight manner from the first cooler housing area (28), is connected for fluid
flow purposes via at least one aperture opening (27) to the third cooling
fluid connection zone (25) and is connected for fluid flow purposes via an
outlet opening (33) to the surrounding area;
- a second cooler module variant (41;58)
- having a first cooler housing section (43,44) which is connected for fluid
flow purposes via corresponding aperture openings (22,24) to the first
(20) and to the second (23) cooling fluid connection zone;
- having a second cooler housing section (45;67) which is connected for
fluid flow purposes to t he first cooler housing section (43,44) and is
connected for fluid flow purposes via at least one aperture opening (27) to
the third cooling fluid connection zone (25);
- having a heat exchanger (52;59), which makes thermal contact with the
two cooler housing sections (43,44);
- a third cooler module variant (72);
- having a first cooler housing area (74) which is connected for fluid flow
purposes via at least one inlet opening (77) to the surrounding area, and
is connected for fluid flow purposes via at least one aperture opening (24)
to the second cooling fluid connection zone (23);

- having a second cooling housing area (75) which is separated in a fluid-
tight manner from the first cooling housing area (74) is connected for fluid
flow purposes via at least one aperture opening (22) to the first cooling
fluid connection zone (20) and is connected for fluid flow purposes via at
least one outlet opening (78) to the surrounding area;
- having a sealing device (81) which seals the third cooling fluid connection
zone (25) such that no cooling fluid can be exchanged between the
machine housing (7) and the cooler module (72);
- a fourth cooler module variant (90;97);
- Having a fist cooler housing area (43; 102) which is connected for fluid
flow purposes via at least one aperture opening (22) to the first cooling
fluid connection zone (20);
- Having a second cooler housing section (44; 103) which is connected for
fluid flow purposes to the first cooler housing section (43; 102) and is
connected for fluid flow purposes via at least one aperture opening (24) to
the second cooling fluid connection zone (23);
- having a heat exchanger (52;99) which makes thermal contact with the
two cooler housing sections (43;44;102;103);
- having a sealing device (92; 104), which seals the third cooling fluid
connection zone (25) such that no cooling fluid can be exchanged
between the machine housing (7) and the cooler module (90;97) through
the third cooling fluid connection zone (25).
2. The set as claimed in claim 1, wherein the aperture openings (18) are
formed in the webs (16).

3. The set as claimed in one of Claims 1 to 2, wherein at least one axial or
radial fan in the cooler housing (21;42;62;73;91;98) and/or in the
machine housing is provided (7) in order to preset an air flow direction.
4. The set as claimed in claim 1 wherein at least one cooler module (41;90)
of the second and fourth cooler module variant is in each case provided
with the cooler housing (91) of the fourth cooler module variant (90)
being identical to the cooler housing (42) of the second cooler module
variant (41), apart from the additional sealing device (92).
5. The set as claimed in claim 1 or 4, wherein the heat exchanger (52) for
the second (41) or fourth (90) cooler module variant is a gas-gas heat
exchanger, in particular an air-air heat exchanger.
6. The set as claimed in claim 1 or 4 wherein the heat exchanger (52;99) for
the second (58) or fourth (97) cooler module variant is a gas-liquid heat
exchanger, in particular an air-water heat exchanger.

ABSTRACT

A SET COMPRISING A PLURALITY OF COOLER MODULES FOR
ASSEMBLY WITH A MACHINE MODULE
The invention relates to an electric unit (1) which comprises a machine module (2)
provided with an electric machine (3) comprising a stator (4) and a rotor. A machine
housing (7) of the machine module (2) receives the electric machine (3). A cooling
module (19) comprises a cooling housing (21), which is fluidically connected to the
machine housing (7) by means of a first cooling fluid connection area (20) in a housing
wall (17) of the machine housing (7) and to at least one second cooling fluid connection
area (23) in the housing wall (17) of the machine housing (7). The inside of the machine
housing (7) can be fluidically connected to the inside of the cooling housing (21) in one
section of the housing wall (17), which is oriented towards the cooling housing (21), by
means of at least one third cooling fluid connection area (25) comprising at least one
cooling fluid through-opening (26). Various cooling module variants can use said third
cooling fluid connection area (25) when other cooling module variants, which can be
used in exchange with the cooling module (19) in the machine module (2), do not use the
third cooling fluid connection area (25). As a result, an electric unit (1), a machine
module (2) therefore and a set comprising a plurality of different cooling modules, which
can meet altered cooling requirements having reduced structural and constructural costs,
can be produced.

ELECTRIC UNIT

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