Fluid circuit for cooling and lubricating hybrid drive assembly of vehicle

Abstract

The invention relates to a hybrid drive assembly (2) for a vehicle, comprising at least one transmission (12), a first electric machine (4) and a second electric machine (8), said first electric machine (4) being housed in a drive housing (6) of said hybrid drive assembly, said second electric machine (8) and said transmission (12) being housed in a transmission housing (10), said hybrid drive assembly comprising a heat exchanger (13) and a lubrication system, the lubrication system comprises at least one pump (36) and a lubrication circuit (38), the lubrication circuit (38) extending at least partially through the heat exchanger (13) and the transmission housing (10).

Description

[0001] The present invention relates to the field of cooling and lubrication systems for hybrid drive components of vehicles. The present invention more particularly relates to cooling and lubricating such hybrid drive components by means of the same fluid.

[0002] Vehicles, especially motor vehicles, are increasingly being used as hybrid vehicles. These hybrid vehicles are driven by a hybrid power assembly, wherein a main electric machine and a generator participate in driving the vehicle, and the main electric machine and the generator participate together or separately in transmitting torque to a transmission, for example, a gear in the transmission transmits the generated torque to a drive shaft.

[0003] The main motor and the generator are components that generate heat during operation. This heat is too great to be conducive to the proper operation of the main motor and the generator. It is therefore known to cool them using a cooling fluid circuit around each of these components, each of which is usually housed in its own housing that needs to be cooled separately.

[0004] The transmission is a component of a hybrid powertrain assembly in which many gears mesh and rub against each other, so lubrication of the transmission is necessary both to limit wear of the parts and also to limit the friction between these parts. It is therefore known to use a lubricating fluid circuit inside the transmission to lubricate the various parts.

[0005] The use of these circuits typically involves a water circuit for cooling the main motor, another water circuit for cooling the generator, and an oil circuit for lubricating the transmission. The accumulation of these circuits significantly increases the size of the hybrid components, the complexity of the circuits used, and the risk of leakage.

[0006] The present invention is based on this background and aims to overcome at least some of the drawbacks of the prior art. In particular, the present invention is concerned with reducing the number of circuits used to cool and lubricate hybrid components.

[0007] Therefore, the present invention relates to a vehicle hybrid drive component, comprising at least one transmission, a first motor and a second motor, wherein the first motor is accommodated in a drive housing of the hybrid component, the second motor and the transmission are accommodated in a transmission housing of the hybrid component, the drive housing and the transmission housing are separated from each other, the hybrid component comprises a heat exchanger outside the drive housing and the transmission housing, the hybrid component comprises a lubrication system, the lubrication system comprises at least one pump and a lubrication circuit, the pump is configured to circulate a lubrication fluid in the lubrication circuit, and the lubrication circuit extends at least partially through the heat exchanger, the drive housing and the transmission housing.

[0008] It is understood that the first motor is housed in the internal space defined by the wall of the drive housing, while the second motor and the transmission are housed in the internal space defined by the wall of the transmission housing. In other words, the first motor is located in one compartment, while the second motor and the transmission are located in another compartment.

[0009] It should be noted that the heat exchanger is a component of the hybrid power assembly, which is separated from the drive housing and the transmission housing, that is, the heat exchanger is a component outside the internal space defined by each of these housings.

[0010] The pump of the lubrication system is fluidically connected to the transmission housing, so that the lubricating fluid present in the transmission housing can be circulated in the lubrication circuit by the pump. The pump can be located inside the transmission housing, in particular, close to the bottom wall of the housing, or outside the transmission housing and fluidically connected to the housing through an orifice provided near the bottom wall of the housing.

[0011] The lubrication circuit passes through both the heat exchanger and the transmission housing and allows the lubricating fluid to be directed over the electric machine in the transmission housing. In this way, the temperature regulation of the electric machine and the lubrication of the transmission are advantageously achieved with the same fluid. More specifically, the lubricating fluid can be cooled in the external heat exchanger to a temperature suitable for cooling the electric machine, and this heat exchange has the advantage of raising the temperature of the lubricating fluid to a viscosity characteristic suitable for lubricating the transmission components, and directing the lubricating fluid over said transmission at the outlet of the electric machine in the transmission housing.

[0012] According to one feature of the invention, the lubrication circuit extends at least partially through the heat exchanger, the transmission housing and the drive housing. The lubrication fluid is thus circulated throughout the hybrid assembly. The lubrication circuit continuously passes through each of these different components of the hybrid assembly, allowing to ensure multiple functions by minimizing the number of fluid circuits required in these functions.

[0013] According to one feature of the invention, the lubrication circuit extends at least partially into the wall of the transmission housing, the lubrication circuit comprising injection means configured to inject lubricating fluid in the direction of the second electric machine. The arrangement of the lubrication circuit in the wall of the transmission housing allows limiting the use of external hydraulic connections where leakage may occur. It will be understood that the main part of the lubrication circuit is arranged directly in the wall of the housing, for example during the manufacture of the housing. The injection means can be formed by simple orifices through which the lubricating fluid flows in the direction of the second electric machine, or by injection nozzles which inject lubricating fluid at a determined pressure in the direction of the second electric machine.

[0014] According to one feature of the invention, the lubrication circuit comprises at least one diverging point, where a first portion of the lubrication circuit extends in the direction of the second electric machine and a second portion of the lubrication circuit extends in the direction of the drive housing.

[0015] According to one feature of the invention, the second part of the lubrication circuit circulates in the main shaft of the transmission, which extends at least partially into the drive housing and is connected in rotation with the first electric machine. It is understood that the main shaft of the transmission comprises a hollow portion through which the lubrication circuit, more specifically the second part of the lubrication circuit, passes. The main shaft of the transmission is arranged partly in the drive housing, where it is connected to the first electric machine, and partly in the transmission housing, where it is connected to the gears of the transmission. The lubricating fluid flowing in the main shaft is intended to pass through the drive housing to flow out of the transmission housing, the main shaft portion present in the transmission housing being radially perforated to allow the passage of the lubricating fluid.

[0016] According to one feature of the invention, the main shaft of the transmission extends in a longitudinal main extension direction, the longitudinal end of the main shaft of the transmission placed in the drive housing is covered by a cover plate attached to the drive housing, and the second part of the lubrication circuit partially extends into said cover plate. In particular, the cover plate has a sealing member that cooperates with the main shaft to ensure the circulation continuity between the part of the lubrication circuit extending into the wall of the cover plate and the part of the lubrication circuit extending into the interior of the main shaft.

[0017] According to one feature of the present invention, the first motor is an axial flow motor.

[0018] According to one feature of the invention, the first electric machine comprises a rotor and a stator, the stator comprising a first stator part housed in a first chamber and a second stator part housed in a second chamber, the second portion of the lubrication circuit extending at least partially through one of the chambers. It is understood that at least the first chamber or the second chamber belongs to the lubrication circuit. The lubrication fluid is in direct contact with the stator part connected to the chamber.

[0019] According to one feature of the present invention, the lubricating fluid is a dielectric fluid.

[0020] According to one feature of the invention, at least a portion of the second part of the lubrication circuit is located outside the drive housing and the transmission housing. This portion of the lubrication circuit is formed by a hydraulic connection (eg a hose).

[0021] According to one feature of the invention, the second part of the lubrication circuit is located at least in part of the connection cover plate outside the drive housing and the transmission housing. In other words, the part outside the drive housing extends from the divergence point to the connection end on the cover plate through a hose. The lubricating fluid then flows into the cover plate and then into the main shaft through the sealing part.

[0022] According to one feature of the invention, the second part of the lubricating circuit extends at least into the wall of the drive housing and into the wall of the transmission housing. In particular, the second part of the lubricating circuit has a portion extending sealed at the connection between the drive housing wall and the transmission housing wall.

[0023] According to one feature of the invention, one of the chambers communicates with a discharge duct leading into the cover plate. The second part of the lubrication circuit thus passes through one of the chambers, which forms a relay point between the duct formed in the drive housing and the duct formed in the cover plate, and is mainly used to fill the interior of the transmission main shaft arranged facing the cover plate with lubricating fluid.

[0024] According to one feature of the invention, one of the chambers communicates with a communication duct that opens into the transmission housing. In this way, a third portion of the lubrication circuit is formed, which extends parallel to the second portion of the lubrication circuit and is intended to regulate the temperature of the other chambers of the electric machine and to lubricate other areas of the transmission.

[0025] The invention also relates to a vehicle comprising a hybrid power assembly according to any of the above features.

[0026] Other characteristics, details and advantages of the invention will become more clearly understood on reading the following description and the examples given as non-limiting examples, taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 Schematically shows a cross-sectional view of a hybrid power assembly according to an embodiment of the present invention, wherein the lubrication system is configured to cool the second motor and lubricate the transmission, and the first motor is cooled by a separate water circuit;

[0028] Figure 2 The schematic diagram shows the lubrication fluid in Figure 1 The circulation conditions within the lubrication system of the illustrated embodiment;

[0029] Figure 3 Schematically shows a cross-sectional view of a hybrid power assembly according to another embodiment of the present invention, wherein the lubrication system is configured here to cool the first motor and the second motor and lubricate the transmission;

[0030] Figure 4 yes Figure 3 Detail of the drawing, showing in more detail the lubrication system at the first motor;

[0031] Figure 5 The schematic diagram shows the lubrication fluid in Figure 3 Circulation conditions within the lubrication system of the illustrated embodiment.

[0032] The features, variants and various embodiments of the invention can be combined with each other according to various combinations, as long as they are not mutually contradictory or mutually exclusive. In particular, it is conceivable that the variant of the invention only includes the selection of features described below separately from other features described, if this feature selection is sufficient to give a technical advantage or distinguish the invention from the prior art.

[0033] In the drawings, the same components in multiple drawings are denoted by the same component numbers.

[0034] In the following description, the longitudinal axis L, the vertical axis V and the transverse axis T are used to indicate the orientation. Figures 1 to 4 The trihedrons L, V, and T shown in are arbitrarily defined.

[0035] Figure 1 and Figure 2 A hybrid power assembly 2 according to a first embodiment of the present invention is shown. More specifically, Figure 1 shows a cross-sectional view of a hybrid power assembly 2, Figure 2 At least one lubricating fluid is shown in Figure 1 The schematic diagram of the internal cycle of the hybrid power assembly 2 is shown in FIG. Figure 2 In FIG. 2 , the circulation of the fluids involved in the hybrid component 2 is indicated by solid arrows.

[0036] Such a hybrid assembly 2 comprises, in particular, a first electric machine 4 accommodated in a drive housing 6 , a second electric machine 8 and a transmission 12 accommodated in a transmission housing 10 , and a heat exchanger 13 outside the drive housing 6 and the transmission housing 10 .

[0037] The first motor 4 is an axial flow motor, which comprises a rotor formed by a rotating disk 14, which is rotatably connected to the main shaft of a transmission 16, and a stator 18, which comprises a first stator component 20 and a second stator component 22 axially arranged on both sides of the rotating disk 14 in sequence.

[0038] The first stator part 20 comprises a winding stator body housed in a first chamber 24, the second stator part 22 comprises a winding stator body housed in a second chamber 26, the turntable 14 being interposed between the stator parts, said stator parts contributing to defining each of the two chambers 24, 26. Figure 4 As can be seen in the figure, which is a detailed view of the hybrid power assembly specifically for the first motor, a gasket 25, 27 is provided in each of the first and second chambers 24, 26 to prevent the cooling fluid present in the chamber from flowing from the center of the drive housing 6 to the main shaft 16 under the action of gravity.

[0039] Therefore, the first chamber 24 extends around the main shaft 16 on the periphery of the internal space of the drive housing, radially, on one side it is limited by its own gasket 25, on the other side by the axial wall 61 of the drive housing 6, and axially, by the turntable 14 and the first radial wall 62 of the drive housing, rotating towards the outside of the hybrid power assembly.

[0040] The second chamber 26 also extends around the main shaft 16 on the periphery of the internal space of the drive housing, radially, in the extension of the axial wall 61 that participates in defining the first chamber 24, by its own gasket 27 and the axial wall of the drive housing, and axially, facing the transmission housing 10, by the turntable 14 and the second radial wall 63 of the drive housing.

[0041] The windings of the stator 18 are powered via electrical connections, not shown here, so that a magnetic field is generated at the first stator part 20 and the second stator part 22. The magnetic field is configured to move the rotating disk 14 about the axis of rotation 28.

[0042] The rotating disk 14 is rotatably connected to the main shaft of the transmission 16, so that the rotation axis 28 of the rotating disk 14 is coaxial with the rotation axis of the main shaft of the transmission 16. It can be understood that the rotation of the rotating disk 14 drives the main shaft of the transmission 16 to rotate.

[0043] like Figure 1 As shown, the main shaft of the transmission 16 extends in the longitudinal main extension direction, that is, parallel to the L axis, partly in the drive housing 6 and partly in the transmission housing 10. More specifically, the main shaft of the transmission 16 is connected in rotation with the first motor 4 at the longitudinal end, and more specifically, is connected with the rotary disc 14 via the longitudinal end opposite to the transmission 12. For this purpose, the main shaft 16 passes through the second radial wall 63 of the drive housing, as well as the radial wall of the transmission housing 10 arranged facing the second radial wall 63.

[0044] In the example shown, without limiting the invention, the transmission 12 comprises a first auxiliary drive shaft 30 and a second auxiliary drive shaft 32, each extending parallel to the main shaft of the transmission 16. The first auxiliary drive shaft 30 is adapted to be connected in rotation with the main shaft of the transmission 16 and the second electric machine 8. The second auxiliary drive shaft 32 is adapted to be connected in rotation with the main shaft of the transmission 16 and a transmission shaft 34. The transmission shaft 34 allows the torque generated by the first electric machine 4 and the second electric machine 8 to be transmitted to the wheels of the vehicle to move them.

[0045] It should be noted that the transmission 12 includes a plurality of claws, fixed gears and idler gears, which ensure that the torque generated by the first motor 4 and the second motor 8 passes through the transmission shaft 34n, and these claws and gears are schematically shown or not shown here, especially in Figure 1 and Figure 3This torque is transmitted to the drive shaft 34, where necessary by increasing or decreasing the rotational speed of the drive shaft 34, depending on whether the fixed gear or the idler gear is engaged by the dog.

[0046] It will be appreciated that the movement of all of these elements within the transmission 12 requires adequate lubrication to limit the effects of friction between the parts on one another.

[0047] To this end, the hybrid assembly 2 comprises a lubrication system comprising at least one pump 36 and a lubrication circuit 38, as shown in detail. Figure 2 The pump 36 is configured to allow lubrication fluid to circulate in the lubrication circuit 38. In the embodiment shown, the pump 36 allows recirculation of lubrication fluid that falls to the bottom of the transmission case 10 due to gravity, ie, in the embodiment shown at the drive shaft 34.

[0048] The lubricating fluid circulated by the pump 36 is sent into the lubricating circuit 38 in the direction of the heat exchanger 13. At the heat exchanger 13, heat exchange occurs between the lubricating fluid and the heat carrier fluid. It should be noted that the part of the lubricating circuit 38 connecting the pump 36 and the heat exchanger 13 is outside the transmission housing 10.

[0049] The lubricating fluid that has exchanged heat within the heat exchanger 13 circulates in the lubricating circuit 38 until it reaches a diverging point 40 where the lubricating circuit 38 is divided into a first portion 42 and a second portion 44. Figure 1 and Figure 2 In the embodiment shown, the divergence point 40 is formed outside the transmission housing 10, and Figures 2 to 5 In the embodiment shown, the divergence point is formed in the transmission housing.

[0050] The first portion 42 of the lubrication circuit 38 extends in the form of a duct at least partially into the wall of the transmission housing 10, which defines an interior space in which the second electric machine 8 and the transmission 12 are located. Furthermore, the wall of the transmission housing 10 comprises an injection device 46 configured to inject lubrication fluid which circulates in the first portion 42 of the lubrication circuit 38 in the direction of the second electric machine 8.

[0051] As shown, these injection means 46 may be orifices provided in the wall of the transmission housing 10. More specifically, one end of these orifices opens into the first portion 42 of the lubrication circuit 38 and the opposite end opens into the transmission housing 10. It will be understood that these injection means 46 allow the lubricating fluid to flow from the first portion 42 of the lubrication circuit 38 towards the second electric machine 8. Alternatively, these injection means 46 may be formed by injection nozzles which spray the lubricating fluid in the direction of the second electric machine 8. It should be noted that the lubricating fluid is a dielectric fluid which allows the operation of the second electric machine 8 to be modified.

[0052] The second portion 42 of the lubrication circuit 38 thus extends from the divergence point 40 to the injection device 46 .

[0053] At the outlet of these injection devices 46, the lubricating fluid comes into contact with the second electric machine 8, causing an exchange of heat between the lubricating fluid and the second electric machine 8. This heat exchange allows the temperature of the second electric machine 8 to be adjusted, if necessary, while changing the temperature of the lubricating fluid in the desired proportion. In particular, the lubricating fluid can cool the second electric machine, even when the lubricating fluid has previously been cooled in the heat exchanger 13. The lubricating fluid, which is heated by this heat exchange with the second electric machine and becomes less viscous, flows under the action of gravity towards the transmission 12, so that the lubricating fluid allows the transmission 12 to be lubricated. It should be noted that the increase in the temperature of the lubricating fluid allows the lubricating fluid to have an appropriate viscosity to lubricate the transmission 12.

[0054] It is understood that when the vehicle is equipped with the hybrid power assembly 2 , the transmission 12 is placed below the second motor 8 relative to the vertical axis V, so that the lubricating fluid flows from the second motor to the gears of the transmission under the action of gravity.

[0055] The lubricating fluid is then collected from the bottom of the housing by pump 36 and reinjected into the lubrication circuit.

[0056] The second portion 44 of the lubrication circuit 38 extends from the divergence point 40 to the drive housing 6. More specifically, Figure 1 and Figure 2 In the embodiment shown, the second portion 44 of the lubrication circuit 38 extends outwardly to the drive housing 6 and the transmission housing 10 and is formed, for example, by a hose. Figures 3 to 5 In the embodiment shown, the second portion 44 of the lubrication circuit extends towards the interior, in particular through several consecutive walls forming the drive housing 6 and the transmission housing 10 .

[0057] Will first refer to Figure 1 and Figure 2The second part 44 of the lubrication circuit 38 is described. The second part 44 of the lubrication circuit 38, in particular in the form of a hose, extends from the convergence point to the outside of the housing and reaches the drive housing 6 at a cover plate 48 connected to the drive housing. The cover plate 48 is fixed to the first radial wall 62 of the drive housing 6, thereby covering the main shaft of the transmission 16 in the longitudinal direction.

[0058] The hose forming the second portion 44 is connected to a head integral with the cover plate and allowing fluid communication between the hose and an internal channel of the cover plate extending the second portion 44 of the lubrication circuit 38. This internal channel opens into a hollow 50 of the main shaft of the transmission 16, the connection being leaktight thanks to a sealing member fixed to the cover plate and formed by a ring with a lip 51 in the embodiment shown.

[0059] In other words, in this embodiment, the second portion 44 of the lubrication circuit 38 extends from the diverging point 40 to a sealing component connected to the cover plate 48 and the hollow portion 50 of the main shaft, which is achieved in sequence through the hoses on the outside of each shell of the hybrid power component of the present invention and the pipeline formed in the cover plate covering the main shaft.

[0060] The lubrication circuit 38 also extends into the hollow portion 50 of the main shaft of the transmission 16, driven in rotation by the first electric machine 4. The hollow portion 50 of the main shaft of the transmission 16 comprises an opening, not shown here, one end of which opens into the hollow portion 50 of the main shaft of the transmission 16 and the opposite end opens into the transmission housing 10.

[0061] It is understood that the lubricating fluid is injected into the transmission case 10 through the opening and then flows to the bottom of the transmission case 10 mentioned above. The lubricating fluid is then extracted by the pump 36 and circulated back to the lubrication circuit 38.

[0062] It should be noted that when the main shaft of the transmission 16 is driven to rotate, the centrifugal force exerted by the main shaft of the transmission 16 on the lubricating fluid promotes the lubricating fluid to be ejected from the hollow portion 50. In addition, the rotation of the main shaft of the transmission 16 allows the lubricating fluid to be evenly ejected throughout the transmission case 10.

[0063] As mentioned above, in Figure 1 and Figure 2 In the embodiment shown, the lubricating fluid can exchange heat with the second motor 8 and lubricate the transmission 12. As for the lubrication of the transmission 12, the lubricating fluid can achieve this function by flowing out of the second motor 8 under the action of gravity on the one hand, and by spraying out from the hollow part 50 of the main shaft of the transmission 16 through the above-mentioned opening on the other hand.

[0064] In the embodiment shown, cooling of the first electric machine 4 is provided by a water circuit 52 which is independent of the lubrication circuit and in which a cooling fluid circulates. The cooling fluid circulates in the wall of the drive housing 6, and more specifically in the wall of the drive housing 6 which is adjacent to the first stator assembly 20 and the second stator assembly 22.

[0065] Now refer to Figures 3 to 5 A specific embodiment of the present invention is described, wherein cooling of the second motor 8 and lubrication of the transmission are always provided by the lubricating fluid circulating in the lubrication circuit 38, but wherein cooling of the first motor 4 is also provided by the lubricating fluid by structural modification of the lubrication circuit.

[0066] In particular, the lubrication circuit 38 is transformed so as to no longer have a hose located outside the housing, but is integrated into the housing, in particular with a second portion 44 of the lubrication circuit 38 which circulates, starting from the divergence point 40, in the wall limiting the housing and in the chambers 24, 26 of the first electric machine 4.

[0067] like Figure 3 As shown, the divergence point 40 of the lubrication system 38 is located in the wall of the transmission housing 10. Figure 1 In the embodiment shown, the first portion 42 of the lubrication circuit 38 extends into the wall of the transmission housing 10 in the direction of the second electric machine 8. The lubricating fluid is sprayed from the spray device 46 in the direction from the second electric machine 8. The lubricating fluid exchanges heat with the second electric machine 8 and then flows to the gears of the transmission under the action of gravity to perform its lubrication function.

[0068] In this case, the second portion 44 of the lubricating fluid circuit extends within the wall of the transmission housing 10 , between the divergence point 40 and the wall of the drive housing 6 .

[0069] At the connection between the drive housing 6 and the transmission housing 10 , a sealing device is used to provide continuity of the second portion 44 of the lubrication circuit 38 from the wall of the transmission housing 10 to the wall of the drive housing 6 , and more specifically, the axial wall 61 participates in radially defining the first chamber 24 and the second chamber 26 .

[0070] The portion of the second portion 44 of the lubrication circuit 38 entering the wall of the drive housing 6 is divided into a first branch 54 and a second branch 56. The first branch 54 is fluidically connected to the first chamber 24 of the stator 18 of the first electric machine 4, while the second branch 56 is connected to the second chamber 26 of the stator.

[0071] It should be noted that the first branch 54 includes at least one first hole, one end of which opens into the first branch 54 and the opposite end opens into the first chamber 24. Similar to the first branch 54, the second branch 56 includes a second hole, one end of which opens into the second branch 56 and the opposite end opens into the second chamber 26. If necessary, a spray nozzle can be provided instead of the hole to allow the lubricating fluid to be sprayed onto the windings of the stator assembly present in each chamber 24, 26.

[0072] It is understood that the first stator assembly 20 and the second stator assembly 22 each exchange heat with a lubricating fluid that is in direct contact with the stator assemblies 20 and 22. Furthermore, it is noted that the lubricating fluid is a dielectric fluid that does not allow the operation of the stator assemblies 20, 22 to be altered.

[0073] Each chamber is filled with a lubricating fluid in which the stator assembly is immersed, the lubricating fluid being retained in each chamber by gaskets 25, 27 which seal their respective chambers in the vicinity of the rotary disc 14. The lubricating fluid present in each chamber and which has increased in temperature due to the heat collected from the corresponding stator assembly is gradually replaced by the lubricating fluid reaching the ends of the branches 54, 56 at a lower temperature through the openings or nozzles. The input of pressurized fluid helps to push part of the fluid present in each chamber, allowing it to be gradually replaced.

[0074] At least one discharge port is provided in each chamber to allow a portion of the lubricating fluid to flow out.

[0075] For example, especially Figure 4 As shown by the arrows visible in FIG. 1 , the lubricating fluid present in the first chamber 24 leaves the first chamber 24 through the supply line 65 provided simultaneously in the first radial wall 62 of the drive housing 6 and in the cover plate 48 under the pressure generated by the fluid specifically reaching the chamber. The lubricating fluid pushed out of the first chamber 24 can then flow into the cover plate 48 and then, as shown in FIG. Figure 1 As depicted, the hollow portion 50 of the main shaft of the transmission 16 is entered.

[0076] For example, especially Figure 4As shown by the arrows visible in the figure, the lubricating fluid present in the second chamber 26, under the pressure generated by the fluid specifically reaching the chamber, leaves the second chamber through the supply line 58 provided in the second radial wall 63 of the drive housing 6 and in the radial wall of the transmission housing 10, so that the lubricating fluid present in the second chamber 26 is sent to the transmission housing 10 to lubricate the transmission 12, and more specifically to one of the auxiliary drive shafts 30. A contact 64 is formed protruding from the radial wall of the transmission housing 10 to contact the second radial wall 63 of the drive housing 6, facing the part of the communication duct 58 formed in the second radial wall 63 of the drive housing 6, and the contact is perforated to form a part of the communication duct 58. It should be noted that a sealing device, here a contact 64, is also used at the connection between the wall of the drive housing 6 and the wall of the transmission housing 10 to ensure that the lubricating fluid circulates in the communication duct 58 in a sealed manner.

[0077] In this embodiment, a third portion 45 of the lubrication circuit 38 can be distinguished, which is successively formed by the second branch 56, the second chamber 26 of the axial drive motor and the connecting duct 58. This third portion 45 allows the temperature of the chamber of the first electric machine 4 to be regulated, which cannot be regulated by the second portion 44 of the lubrication circuit, to be regulated, and also allows the secondary drive shaft to be lubricated, which cannot be lubricated by the second portion 44 of the lubrication circuit.

[0078] In the example shown, it is noted that only one orifice is formed in the first chamber 24 to communicate with the supply pipe 64, and only one orifice is formed in the second chamber 26 to communicate with the exhaust pipe 58. However, it is understood that, without departing from the context of the present invention, each chamber may be equipped with several orifices, each of which communicates with a supply pipe or an exhaust pipe. In particular, the orifices may be arranged near the axial wall defining the chamber, with the intention that the orifices are arranged vertically at the lowest point when the hybrid drive assembly is mounted on the vehicle.

[0079] In other words, Figures 3 to 5 In the embodiment shown, the second portion 44 of the lubrication circuit 38 therefore extends from the divergence point 40 to a sealing component connected to the cover plate 48 and the hollow part 50 of the main shaft. This is mainly achieved in the wall of the housing forming the hybrid component of the present invention and through a duct formed in the cover plate covering the main shaft. The passage from one housing to another or from one housing to the cover plate is sealed by appropriate means.

[0080] Furthermore, the second portion of the lubrication circuit 44 also has a buffer zone of lubricating fluid formed in the first chamber 24 of the first electric machine 4 , which is supplied by the first branch 54 and emptied through the drain line 65 .

[0081] Finally, the lubrication circuit differs in that the third portion 45 , as described above, extends parallel to the second portion 44 .

[0082] Therefore, in Figures 3 to 5 In the embodiment shown, the lubricating fluid circulating in the various parts of the lubrication circuit can exchange heat with the second electric machine 8 and with the first electric machine 4, it being noted that these temperatures are substantially carried out in parallel. In the same cycle, the lubricating fluid used for heat exchange with the first electric machine is not heated by previously passing through the second electric machine before being reinjected by the pump 36, and vice versa. Therefore, the temperature regulation is particularly effective for the two electric machines, since the temperature of the lubricating fluid in contact with these electric machines is substantially equal to its temperature at the outlet of the heat exchanger 13.

[0083] Furthermore, the lubricating fluid allows lubricating the transmission 12 by flowing out of the second electric machine 8 under gravity and by ejecting from the hollow 50 of the primary shaft of the transmission 16 through the above-mentioned opening and finally from the interior of the secondary shaft.

[0084] therefore, Figures 3 to 5 The embodiment shown in is particularly advantageous because the lubrication circuit is internal to the hybrid drive assembly (and therefore has no external hoses affecting the volume of the hybrid assembly), allows for efficient regulation of the temperature of the two independent motors, and allows for efficient lubrication of the transmission due to access to the circuit board from multiple areas.

[0085] The invention achieves its object by providing a vehicle hybrid drive assembly in which the cooling of at least one electric machine and the lubrication of the transmission are achieved by the same lubrication circuit. This common lubrication circuit, which ensures both cooling and lubrication, allows the compactness of the hybrid assembly to be increased and the risk of leakage that may occur in a hybrid assembly with multiple circuits to be reduced.

Claims

1. A vehicle hybrid drive assembly (2), comprising at least one transmission (12), a first motor (4) and a second motor (8), wherein the first motor (4) is accommodated in a drive housing (6) of the hybrid assembly (2), the second motor (8) and the transmission (12) are accommodated in a transmission housing (10) of the hybrid assembly (2), the drive housing (6) and the transmission housing are separated from each other, the hybrid assembly (2) comprises a heat exchanger (13) outside the drive housing (6) and the transmission housing (10), the hybrid assembly (2) comprises a lubrication system, the lubrication system comprises at least one pump (36) and a lubrication circuit (38), the pump (36) being configured to circulate a lubrication fluid in the lubrication circuit (38), the lubrication circuit (38) extending at least partially through the heat exchanger (13) and the transmission housing (10).

2. A hybrid power assembly (2) according to the preceding claim, wherein the lubrication circuit (38) extends at least partially into the wall of the transmission housing (10), the lubrication circuit (38) comprising an injection device (46) configured to inject lubrication fluid in the direction of the second electric machine (8).

3. A hybrid power assembly (2) according to any of the preceding claims, wherein the lubrication circuit (38) comprises at least one divergence point (40) at which a first portion (42) of the lubrication circuit (38) extends in the direction of the second electric machine (8) and a second portion (44) of the lubrication circuit (38) extends in the direction of the drive housing (6).

4. The hybrid power assembly (2) according to the preceding claim, the second portion (44) of the lubrication circuit (38) circulates in a main shaft of the transmission (16), the main shaft extending at least partially into the drive housing (6) and being rotationally connected to the first electric machine (4).

5. A hybrid power assembly (2) according to the preceding claim, wherein the main shaft of the transmission (16) extends in a longitudinal main extension direction, the longitudinal end of the main shaft of the transmission (16) placed in the drive housing (6) is covered by a cover plate (48) attached to the drive housing (6), and the second portion (44) of the lubrication circuit (38) partially extends into the cover plate (48).

6. A hybrid power assembly (2) according to any one of claims 1 to 5 in combination with claim 3, wherein at least a portion of the second portion (44) of the lubrication circuit (38) is located outside the drive housing (6) and the transmission housing (10).

7. The hybrid power assembly (2) according to the preceding claim in combination with claim 5, wherein the second portion (44) of the lubrication circuit (38) is connected to a cover plate at least in part outside the drive housing and the transmission housing.

8. A hybrid power assembly (2) according to any one of claims 1 to 5 in combination with claim 3, wherein the second portion (44) of the lubrication circuit (38) is formed in a wall of the transmission housing (10) and in a wall of the drive housing (6).

9. A hybrid power assembly (2) according to the preceding claim, wherein the first electric machine (4) comprises a rotor and a stator (18), the stator (18) comprising a first stator part (20) housed in a first chamber (24) and a second stator part (22) housed in a second chamber (26), the second portion (44) of the lubrication circuit (38) extending at least partially through one of the chambers (24, 26).

10. A hybrid power assembly (2) according to the preceding claim in combination with claim 5, wherein one of the chambers (24, 26) communicates with a drain duct (65) opening into the cover plate (48).

11. The hybrid power assembly (2) according to claim 9 or 10, wherein one of the chambers (24, 26) communicates with a communication duct (58) leading into the transmission housing (10).

12. A vehicle comprising a hybrid power assembly (2) according to any one of claims 1 to 11.

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