Drive device for motor vehicle

Abstract

The invention relates to a motor vehicle drive, comprising a housing with an engine cavity and an adjacent transmission cavity separated by an inner end wall, an electric motor arranged in the engine cavity, the electric motor having a stator fixed to the housing and a rotor having a rotor shaft rotatably supported in the engine cavity and passing through the inner end wall, and a transmission arranged in the transmission cavity, the electric motor having an input pinion fastened to a rotor shaft serving as a drive shaft there and an output gear connectable or connected to a driven end, and an oil reservoir, from which oil can be guided to the rotor shaft via an oil supply system for cooling the electric motor and from the rotor shaft back to the oil reservoir via an oil discharge system, wherein the housing wall of the engine cavity has a cooling water jacket surrounding the stator along the circumference of the stator for additional cooling of the electric motor, wherein at least a portion of the oil reservoir is constructed as a labyrinth cavity arranged below the engine cavity, the upper side of which is thermally coupled to the cooling water jacket.

Description

Technical Field

[0001] The present invention relates to a driving device for a motor vehicle, comprising

[0002] - a housing with an engine chamber and a transmission chamber adjoining the engine chamber and separated from the engine chamber by an inner end wall, respectively delimited by the inner end wall, an associated outer end wall and a casing wall extending in the axial direction between the inner end wall and the associated outer end wall,

[0003] - an electric machine arranged in the engine cavity, comprising a stator fixed to a housing and a rotor arranged radially in the stator, the rotor having a rotor shaft passing through the inner end wall and rotatably supported in the engine cavity,

[0004] - a transmission arranged in the transmission chamber, with an input pinion fastened to the rotor shaft, which serves here as a drive shaft, and an output gear connectable or connected to the driven end, and

[0005] an oil reservoir, from which oil can be conducted via an oil supply system to the electric machine, in particular to the rotor shaft, for cooling purposes and from which oil can be conducted via an oil discharge system back into the oil reservoir,

[0006] In this case, the housing wall of the engine chamber has a cooling water jacket surrounding the stator along its circumference for additional cooling of the electric machine. Background Art

[0007] Such a drive device is known from JP 2012-105457 A.

[0008] The document discloses an electric drive for a motor vehicle, which is configured as a compact drive device, which includes an actual drive unit on the one hand and a transmission for converting and distributing the torque provided by the motor on the other hand. The two units are arranged in a common housing, but the housing is divided into roughly separate chambers, namely the engine chamber and the transmission chamber, due to the different requirements of the individual units. The two chambers are passed through by a common shaft, which acts as a rotor shaft in the engine chamber and as a transmission input shaft in the transmission chamber. This means that the engine chamber and the transmission chamber are arranged adjacent to each other in the axial direction and share a common end wall, which is referred to as the inner end wall here. On the axially corresponding other opposite sides, each chamber is limited by another end wall, which is referred to as the outer end wall here. Between the (common) inner end wall and each outer end wall, a correspondingly associated housing wall extends in the axial direction.

[0009] The person skilled in the art will understand that terms indicating a general relative orientation or position (such as "next to", "below", "above", etc.) always refer to the final installation position of the drive device in the motor vehicle, unless otherwise stated. The same applies to absolute orientation specifications such as "vertical" and "horizontal". Symmetry-specific terms (such as "axial", "radial", etc.) are always to be understood in the context of the correspondingly described symmetry unit.

[0010] In the case of high-power electric drives, it is generally accepted that the accumulated waste heat is discharged via two cooling systems that are independent in terms of material and space, namely via a water-based cooling system and an oil-based cooling system, as disclosed in the aforementioned document, wherein the oil-based cooling system usually has the additional function of lubricating the movable parts. The water cooling of the electric machine, which is usually designed as an internal rotor machine, is designed as a stator cooling in the form of a cooling water jacket. A cooling water jacket is a cooling water line system that is integrated into the housing wall of the engine chamber and surrounds the stator. It can have the shape of a spiral cooling coil; in the aforementioned document, however, long flat channels are integrated into the housing wall of the engine chamber to increase the cross section. In the device disclosed in the aforementioned document, the oil-based cooling system includes an oil reservoir that is designed as an oil sump, which extends over the lower region of the transmission chamber and the engine chamber, which regions are connected to each other via an overflow. The output gear of the transmission extends into a transmission oil pan arranged in the lower region of the transmission chamber, so that the oil in the transmission oil pan is constantly stirred when the output gear rotates and also wets the teeth of the output gear. In addition, oil is drawn from the transmission oil pan by means of an oil pump and pumped into the annular gap via a vertical pipe coaxial to the hollow rotor shaft and forming an annular gap with its inner wall, in order to produce internal cooling of the rotor. At its axial end, the rotor shaft is open, so that the oil flowing out of the rotor shaft again flows directly back into the transmission oil pan on the one hand and flows back to the engine oil pan in the lower region of the engine chamber in a circuitous manner via a cover plate chamber axially adjacent to the engine chamber on the side facing away from the transmission. There, it flushes and cools the lower region of the stator. In order to also cool the upper region of the stator, corresponding perforations are provided in the upper region of the engine chamber housing wall, through which the oil is pumped to the upper stator region, in particular to the winding heads, and then also accumulates in the engine oil sump. The two cooling systems are thermally coupled to one another. The cooling water jacket is therefore connected to a water / oil heat exchanger in the transmission oil sump via a line system.

[0011] This known device has several disadvantages. On the one hand, the thermal coupling of the two cooling systems via the heat exchanger in the transmission oil sump is disadvantageous. The heat exchanger requires a lot of space in the very narrow transmission chamber. In addition, the fluid connection to the cooling water jacket requires complex pipe laying. In addition, the common oil sump extending over the transmission chamber and the engine chamber and provided with an overflow in the direction of the engine chamber is disadvantageous and increases the risk of oiling the air gap between the rotor and the stator of the electric machine, which can lead to significant performance losses, and on the other hand increases the risk of the transmission chamber drying out in the event of high cooling requirements for the electric machine and correspondingly high operation of the oil pump. Summary of the invention

[0012] The object of the present invention is to develop a drive device of the generic type in such a way that, while achieving similarly good cooling of the electric machine, a simpler construction and improved protection against oil filling of the air gap are achieved.

[0013] This object is achieved in conjunction with a drive device for a motor vehicle, the drive device comprising: a housing with an engine cavity and an adjacent transmission cavity separated by an inner end wall, respectively limited by the inner end wall, an associated outer end wall and a casing wall extending in the axial direction between the inner end wall and the associated outer end wall, an electric motor arranged in the engine cavity, with a stator fixed to the housing and a rotor with a rotor shaft passing through the inner end wall and rotatably supported in the engine cavity, and a transmission arranged in the transmission cavity, with a rotor fastened therein. When an input pinion on the rotor shaft of the drive shaft and an output gear that can be connected or connected to the driven end, and an oil reservoir, the oil can be conducted from the oil reservoir via an oil supply system to the rotor shaft for cooling the motor and from the rotor shaft back into the oil reservoir via an oil discharge system, wherein the housing wall of the engine chamber has a cooling water jacket surrounding the stator along the circumference of the stator for additional cooling of the motor, in that the area of ​​the oil reservoir is constructed as a labyrinth chamber arranged below the engine chamber, the upper side of which is thermally coupled to the cooling water jacket and the lower side of which is an outer wall area of ​​the drive device.

[0014] As its central element, the invention provides for the provision of a new, separate chamber below the engine chamber. This chamber, referred to here as a labyrinth chamber, is a component of an oil reservoir into which the oil which has performed its cooling task in the region of the rotor shaft and / or the stator is directed back, so that from there it undergoes a new cooling cycle with a complete or partial return via the transmission oil sump, depending on the embodiment. The newly provided chamber is referred to as a labyrinth chamber because it contains oil-conducting elements which force the oil flowing through the labyrinth chamber to move in a meandering manner. The oil then remains in the labyrinth chamber for a relatively long time, so that it can interact with the thermal coupling element for a correspondingly long time.

[0015] An important thermal coupling element is a cooling water jacket that is integrated into the engine chamber housing wall and is therefore placed above the labyrinth chamber between it and the engine chamber. The oil in the labyrinth chamber can dissipate heat to the cooling water jacket via the upper side of the labyrinth chamber. Because the lower side of the labyrinth chamber is also the outer wall of the housing, there is a thermal coupling relative to the surrounding environment, especially relative to the surrounding air flowing around the housing. So the oil in the labyrinth chamber can also dissipate heat to the surrounding air. In other words, the thermal coupling between the oil-based and water-based cooling systems is achieved without the space-intensive heat exchanger in the transmission oil pan and without these pipes connected to the cooling water jacket. At the same time, the heat input to the water-based cooling system is reduced because the thermal coupling of the labyrinth chamber to the surrounding environment makes additional heat dissipation paths available. And finally, the oil return guide under the engine chamber provides the possibility of eliminating the engine oil pan, which significantly reduces the risk of air gap oiling of the motor.

[0016] In order to improve the thermal coupling between the cooling water jacket and the labyrinth chamber, in an improved solution of the present invention, it can be arranged that the outer side of the engine chamber housing wall has heat sinks that extend into the labyrinth chamber and can flow around in the boundary area relative to the labyrinth chamber. These heat sinks increase the contact area between the oil in the labyrinth chamber and the wall of the cooling water jacket. The heat sink can be an oil guide element that ensures the meandering movement of the oil in the labyrinth chamber; alternatively, the heat sink can be an additional structure relative to other oil guide elements. For example, the oil guide element can also be configured as a heat sink (or cooling fin, i.e., Kuehlrippe) protruding from the bottom of the labyrinth chamber, which improves the thermal coupling to the surrounding air. In order to improve the cooling effect, structures of other shapes can also be provided, such as pins, etc.

[0017] As is known in principle from the prior art, in the case of the present invention, it is also preferably provided that the rotor shaft is hollow and oil can be guided into the hollow rotor shaft via an oil supply system and from the hollow rotor shaft via an oil discharge system into an oil reservoir, in particular a labyrinth. It is preferably provided that the hollow rotor shaft has a radial opening in its axial end region close to the end wall in the engine cavity, through which the oil can be thrown from the hollow interior of the rotor shaft into the axial end region of the stator when the rotor rotates. Such an effect is achieved with the axial opening, provided that there is a sufficient distance between the opening and the wall of the engine cavity. Unlike the prior art, the oil supplied to the hollow rotor shaft thus does not flow out into the cavity adjacent to the engine cavity in any case, but flows into the engine cavity, more precisely in the form of a centrifugally driven jet, which is directed outwards toward the axial stator end, in particular the winding head arranged there. As a result, the areas of the stator that particularly require cooling can be wetted with a large oil volume in a targeted manner. Owing to the lack of direct thermal coupling, these stator regions experience only a small amount of cooling via the cooling water jacket; oil sump wetting or dripping water wetting (as known from the prior art) in contrast is on the one hand unevenly distributed over the stator and on the other hand highly volume-limited.

[0018] In order to prevent the construction of an engine oil sump with the risk of air gap oiling, especially in the case of high centrifugal volumes, it is preferably provided that the engine chamber has, in its axial end region close to the end wall, an engine chamber outflow that opens (directly or indirectly) into the labyrinth chamber. The oil thrown into the axial end region of the stator can then be discharged directly into the labyrinth chamber below the engine chamber after fulfilling its cooling task, so that no disruptive oil level can be formed in the engine chamber. In order to completely ensure that the construction of the engine oil sump in the engine chamber is not endangered even in the case of oil blockage in the labyrinth chamber, in a development of the invention it can be provided that the engine chamber has an engine chamber overflow to the transmission oil sump through the inner end wall, which is arranged above the engine chamber outflow (and obviously below the air gap of the electric machine).

[0019] Different approaches are possible regarding the flow of oil in the labyrinth chamber. In a first approach, it is provided that two engine chamber outflows lead into a common labyrinth chamber (which can in particular be a single labyrinth chamber). The common labyrinth chamber extends over the entire axial length of the engine chamber, which is arranged below the engine chamber. Two engine chamber overflows arranged at the axial ends of the engine chamber discharge oil from the engine chamber, i.e. at two axial ends of the labyrinth chamber that are opposite to each other, into the labyrinth chamber. The oil flows from the two engine chamber outflows are then mixed in the labyrinth chamber and jointly find their way to the outlet of the labyrinth chamber, the design of which will be further discussed below. This is a technically simpler variant.

[0020] In the case of a large oil volume flow and a very flat design of the labyrinth chamber, it is theoretically conceivable, however, that the confluence of the two oil flows leads to an oil blockage in the labyrinth chamber, which in the most unfavorable case continues into the engine chamber. In the embodiment in which there is no engine chamber overflow to the transmission oil pan, such a blockage may cause the oil level in the engine chamber to rise to the air gap of the motor, which is then filled with oil in an unfavorable manner. In order to completely eliminate this situation, in the case of the second mode, it is provided that the labyrinth chamber has two separate labyrinth chambers, into which each of the two engine chamber outflows leads. The two oil flows then lead to the outlet of the labyrinth chamber on separate paths, thereby eliminating blockage in the labyrinth chamber in the case of a suitable design of the individual oil circuits. Here, the oil circuit on the side of the engine chamber facing away from the transmission can be guided on a bend through the cover plate chamber axially connected to the engine chamber here.

[0021] An overflow to the transmission oil pan is preferably provided as an outlet of the labyrinth chamber. Alternatively or additionally, it can be provided that each labyrinth chamber is fluidically connected to a suction chamber of the oil pump (common in the case of a plurality of labyrinth chambers). In an embodiment in which an active oil circulation is provided by means of an oil pump, a separate suction chamber connected to the labyrinth chamber is a better oil extraction point for the oil pump than the transmission oil pan in the transmission chamber. In this way, it is thus reliably prevented that the oil pump lowers the oil level in the transmission oil pan too much and thus prevents sufficient transmission lubrication. Conversely, for example, in the event that the pump does not work, oil blockage in the suction chamber should also be prevented, which could extend into the labyrinth chamber. Therefore, in a refinement of this embodiment, it is provided that the suction chamber is (also) connected to the transmission oil pan via an overflow, i.e. a suction chamber overflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further details and advantages of the invention emerge from the following detailed description and the accompanying drawings.

[0023] in:

[0024] Figure 1 : shows a highly schematic longitudinal section through a preferred embodiment of the drive device according to the invention,

[0025] Figure 2 : Shows the Figure 1 The cross-sectional diagram of the section line II-II in FIG.

[0026] Figure 3 : Shows the Figure 1 The cross-sectional diagram of the section line III-III in FIG.

[0027] Figure 4: shows a similar Figure 3 A cross-sectional diagram of

[0028] Figure 5 : shows a similar process through another alternative embodiment Figure 1 A cross-sectional diagram of

[0029] Figure 6 : Shows the Figure 5 The cross-sectional diagram of the section line VI-VI in FIG.

[0030] Figure 7 : A partial cross-sectional view showing another alternative embodiment,

[0031] Figure 8 : Shows the Figure 7 The cross-sectional diagram of the section line VIII-VIII in FIG.

[0032] FIG. 9 : shows a schematic representation of the oil reservoir for illustrating its position in the transmission,

[0033] Fig.10 : shows the strong flow path with the plotted Fig. 9 A cross-sectional view of an oil reservoir,

[0034] Fig.11 : shows the weak flow path with the plotted Fig. 9 A cross-sectional view of the oil reservoir, and

[0035] Fig.12 : Shows Fig. 9 0026] FIG20 is a reverse cross-sectional illustration of an oil reservoir. DETAILED DESCRIPTION

[0036] The same reference numbers in the drawings indicate the same or similar elements.

[0037] Figure 1 A longitudinal section through an embodiment of a drive device 10 according to the invention is shown in highly schematic diagram form. The drive device 10 comprises a housing 12, which is divided into a motor chamber 14 and a transmission chamber 16. The motor chamber 14 and the transmission chamber 16 are arranged axially adjacent to each other. The motor chamber 14 and the transmission chamber 16 are separated from each other by an intermediate wall, which is referred to here as an inner end wall 18. Arranged opposite the inner end wall 18 in the axial direction, the motor chamber 14 is limited by an outer (motor chamber) end wall 20 and the transmission chamber 16 is limited by an outer (transmission chamber) end wall 22. In the radial direction, the motor chamber 14 is limited by a (motor chamber) housing wall 24 and the transmission chamber 16 is limited by a (transmission chamber) housing wall 26.

[0038] An electric machine 28 with a stator 30 fixed to the housing and a rotor 32 rotatable in the stator 30 is arranged in the engine chamber 14. The rotor 32 has a rotor shaft 34, which is supported on the one hand in the inner end wall 18 and on the other hand in the outer engine chamber end wall 20. The rotor shaft 34 is hollow-designed at least in its central region. Here, the rotor shaft 34 passes through the inner end wall 18 so as to extend into the transmission chamber 16 as a drive shaft 36. Alternatively, it is also possible that the drive shaft 36 is a separate shaft that is coaxially connected to the rotor shaft 34.

[0039] A transmission 38, in particular a transmission, is arranged in the transmission chamber 16. Acting as an input gear of the transmission 38 is a drive pinion 40, which is fixed in a rotationally fixed manner on the drive shaft 36. The concept of a pinion should be understood broadly and includes not only a gear that is plugged onto the shaft but also a toothing that is integrally formed with the shaft. It is in a torque-transmitting connection with an output gear 42 via a plurality of toothing stages. The output gear 42 is connected to a driven end, in particular a differential transmission, in a manner not shown in detail.

[0040] In addition, an oil container 44 is arranged in the transmission chamber 16, and its special design is further described below. Figures 9 to 12 This will be further explored in the text.

[0041] In the lower region of the transmission chamber 16 there is a transmission oil pan 46, into which the lower region of the output gear 42 projects from above. In the case of rotation, its toothing receives oil from the transmission oil pan 46 and throws it into the oil container 44. The oil at least partially leaves the oil container via a rotor shaft outlet 48 and flows via corresponding oil lines into the hollow rotor shaft 34.

[0042] The hollow rotor shaft 34 is provided with steps 50 on both sides, which essentially allow the construction of an oil sump within the hollow rotor shaft 34 and thus the distribution of the oil over its axial length. However, the oil can leave the hollow rotor shaft 34 via radial openings 52. In the case of rotation of the rotor shaft 34, this is achieved centrifugally driven in the form of oil ejection, which in this way reaches the winding head 54 of the stator 30 in the case of correct positioning of the radial openings 52.

[0043] The path that the oil takes here and that will be described in greater detail below is shown in the figures as hatched oil transport arrows.

[0044] In the embodiment shown, the cooling water jacket 56 is integrated into the housing wall 24 of the engine chamber 14. In the embodiment shown, the cooling water jacket is designed in the form of a flat tube arrangement that circumferentially extends inside the engine chamber housing wall 24. The connection of the cooling water jacket 56 to a more complex water supply system is not shown in detail in the figures as it is not essential to the invention.

[0045] Below the engine chamber 14, there is a labyrinth chamber 58 separated by the lower part of the engine chamber housing wall 24, which is connected to the engine chamber 14 via an engine chamber outflow 60. In particular, the oil that has reached the engine chamber 14 on the path described above can flow out into the labyrinth chamber 58 via the engine chamber outflow 60 without the risk of a too high engine oil sump being constructed. For safety reasons, it can be provided, as in the illustrated embodiment, that the engine chamber 14 is additionally connected to the transmission chamber 16, in particular the transmission oil sump 46, via an engine chamber outflow 62. In this way, filling of the air gap 64 between the stator 30 and the rotor 32 of the electric machine 28 with oil can be reliably prevented.

[0046] The cover of the labyrinth chamber 58, that is to say the outer side of the lower region of the engine chamber housing wall 24, is provided with cooling fins 66, which extend deep enough into the labyrinth chamber 58 so as to be flushed by the oil accumulated there. In an alternative embodiment, not only is a thermal coupling between the oil in the labyrinth chamber 58 and the cooling water jacket 56 provided via the cooling fins 66, but the engine chamber housing wall 24 extends deeper into the labyrinth chamber 58 and is directly wetted by the oil. The maximum height of the oil level in the labyrinth chamber 58 is determined by the height of the labyrinth chamber overflow 68, via which the labyrinth chamber 58 is connected to the transmission chamber 16, in particular the transmission oil pan 46. In this way, heat exchange can be achieved between the cooling water jacket 56 and the oil in the labyrinth chamber 58 via the cooling fins 66, wherein the oil is further cooled thereby, i.e. the bottom 70 of the labyrinth chamber 58 is the outer wall of the housing 12, which is surrounded by the surrounding air. In this way, particularly efficient cooling of the oil and water is achieved.

[0047] Figure 2 Shows along Figure 1 The section along the section line II-II. Figure 3 Shows along Figure 1 The two diagrams show that the labyrinth chamber 58 has a plurality of oil-conducting elements 72 extending through its entire height, which force the oil flowing in through the engine chamber outflow 60 into a meandering motion. As a result, the thermal contact with the cooling fins 66 is enhanced and thus the heat exchange is improved.

[0048] Further in Figure 2 and 3 It can be seen that the labyrinth chamber 58 transitions into the suction chamber 74 of the oil pump 76, into which the suction nose 77 of the oil pump projects. Based on this, oil can be pumped to different locations of the drive device 10 that require lubrication and cooling when the pump is running. Figure 2The corresponding oil distribution channel 78 connected to the oil pump 76 can be seen in it, which will be discussed in more detail below.

[0049] Furthermore, excess oil from the labyrinth 58 or the suction chamber 74 can pass via the labyrinth overflow 68 into the transmission chamber 16 and in particular into the transmission oil sump 46 there.

[0050] exist Figure 3 In the embodiment of the present invention, the labyrinth chamber 58 generally comprises a single labyrinth chamber into which two engine chamber outflows 60 flow. This means that, from Figure 3 The oil in the labyrinth chamber 58 is discharged from the engine chamber 60 on the left side. Figure 3 The oil flows through the engine chamber outflow 60 on the right in the middle and mixes there with the oil flowing in through it. In terms of the dimensions, it must be taken into account that in the case of large volume flows, no oil blockage occurs there, even in particularly unfavorable situations. In order to completely eliminate this, in one embodiment, for example, Figure 4 As shown in , the labyrinth chamber is divided into two different labyrinth chambers, each of which is connected to the labyrinth chamber in the engine chamber outflow 60. In addition, reference can be made to the above description in full.

[0051] Figure 5 An alternative embodiment of the drive device 10 is shown. Figure 1 In this embodiment, the outer end face 20 axially adjacent to the engine cavity 14 (that is, at Figure 5 A cover plate cavity 80 is connected to the outer end face 20 (right side), the purpose of which is mainly to collect the oil that penetrates through the outer end face 20. In particular, it is only difficult to ensure the oil filling of the rotor shaft bearing (not shown in detail in the drawings) in the outer engine chamber end wall 20 without the oil flowing out of the engine chamber 14 through the bearing. The oil can be collected in the cover plate cavity 80 and directed back to the previously described oil circuit in a manner further described below. In addition, the presence of the cover plate cavity 80 provides the possibility of targeted additional utilization.

[0052] Therefore Figure 5 In the embodiment of the outer engine chamber end wall 20, similar to the engine chamber overflow 62, there is a further engine chamber overflow 82 in the inner end wall 18, through which oil can reach the cover chamber 80 from the engine chamber 14. In the embodiment shown, the cover chamber 80 is connected to the oil container, in particular the front chamber downstream of the labyrinth chamber 58, such as the suction chamber 74, via a labyrinth chamber overflow 84. As in Figure 6 As shown in Figure 4In the embodiment shown in FIG. 5 , the labyrinth chamber 58 can be divided into two chambers. In this embodiment, the oil flowing into the labyrinth chamber 58 through the engine chamber outflow 60 on the transmission chamber side flows through only one, that is, in Figure 6 The labyrinth chamber in the middle and upper part and then flows around through the cover chamber 80 Figure 6 In contrast, the oil flowing into the labyrinth chamber 58 through the engine chamber outflow 60 on the cover chamber side only flows through the other, i.e. Figure 6 The labyrinth chamber in the lower middle part. The two oil flows only merge in the chamber downstream of the labyrinth chamber (for example, the suction chamber 74). Oil blockage in the labyrinth chamber is thus reliably avoided. This form of oil diversion is possible even in the case of a variant without a cover chamber 80. Here, the outflow from the (upper) labyrinth chamber and the inlet to the suction chamber can be connected via corresponding pipelines. It is also possible that another engine chamber overflow 82 replaces the engine chamber outflow 60 on the cover chamber side.

[0053] Figure 7 An embodiment is shown in which the cover plate chamber 80 undergoes an alternative or additional use. This type of embodiment necessarily requires an oil pump 76 which draws oil from an oil container, in particular from the suction chamber 74, and feeds it into the oil distribution channel 78. Figure 7 In the embodiment shown, the oil distribution channel 78 is as shown in Figure 2 As can be seen in the diagram, the oil distribution channel 78 extends in a wedge-shaped component between the engine chamber housing wall 24 and the cover of the suction chamber 74. In the embodiment shown, it is divided in particular into two opposite branches 78a, 78b. The second branch 78b of the oil distribution channel 78, which is referred to here, is Figure 7 The left branch in the middle leads to the transmission chamber 16, wherein the branch passes through a constriction barrier 85 in order to prevent too strong an outflow into the transmission chamber 16. Therefore, the main part of the pumped oil is discharged via the first branch 78a of the oil distribution channel as described in detail below. The constriction barrier 85 in the second branch 78b of the oil distribution channel 78 is preferably equipped with a magnet 86, in particular a ring magnet, upstream and adjacent to it, in order to remove metal chips from the oil circuit.

[0054] The first branch 78 a of the oil distribution channel 78 opens into the cover plate chamber 80 , to which an oil guide pipe 88 is connected at its free end. Figure 8 Shows the Figure 7 A sectional view of the section line VIII-VIII in FIG. 1 and below with Figure 7Discussed together. The oil guide pipe 88 leads in an arc to a fastening star 98, which is fixed with its cantilever arms to the outside of the external engine chamber end wall 20. At its center, it fastens the end of the oil guide pipe 88, which is configured as a pipe socket 92, which extends into the open end of the hollow rotor shaft 34. As at its end on the transmission chamber side, the hollow rotor shaft 34 is also equipped with a step 50 in its interior here, through which the pipe socket 92 protrudes axially. Therefore, the oil pumped via the second branch 78a of the oil distribution channel 78 is pumped directly into the inner cavity of the rotor shaft 34, which helps to build an oil pan there. For other oil flows, refer in particular to Figure 1 The above description in the context of .

[0055] exist Figure 7 and 8 In the embodiment shown in , the oil guide tube 88 performs another task. In this embodiment, the busbars 94 for electrifying the stator 30 are guided through the cover plate cavity 80 in sections. The oil guide tube 88 describes an arc in the cover plate cavity 80, which passes close to these busbars 94. In the closest area, the side wall of the oil guide tube 88 has a nozzle opening 96, from which oil is sprayed onto the busbars to cool these busbars. As professionals know, the size of the nozzle opening 96 is preferably realized in this way, that is, in the case of the oil pressure preset by the oil pump 76 in the oil guide tube 88, continuous and sufficient flushing of the busbars 96 can be achieved, wherein, however, enough oil is still retained in the oil guide tube 88 to be pumped into the hollow rotor shaft 34 for its cooling.

[0056] Fig. 9 A particularly preferred embodiment of the oil container 44 is shown in its final assembly position in the transmission 38. In the present case, the drive pinion 40 and the output gear 42 are particularly important in the transmission.

[0057] As in Figure 1 As described in the context of the present invention, the output gear 42 is immersed in the Fig. 998 . The oil container 44 is shown in the figure in the transmission oil pan 46, so that its gearing receives oil during rotation and is thrown into the inlet opening 98 as indicated by the hatched oil delivery arrow. The oil container 44 has a plurality of outflows in its side wall, which will be discussed in detail below. Only the transmission oil pan outlet 100, which is drawn with an oil delivery arrow, should be pointed out here, which allows the oil to flow out of the oil container 44 into the drive pinion groove 102. The drive pinion groove 102 is arranged below the drive pinion 40 in such a way that the drive pinion is partially immersed in the drive pinion groove, so that its lower area is wetted by the oil pan accumulated in the drive pinion groove. The transmission oil pan outlet 100 is the lowest oil outlet of the oil container 44, which allows the maximum possible emptying of the oil pan into the transmission oil pan on the way to the drive pinion groove 102 overflowing toward the transmission oil pan 46. This ensures that the drive pinion 40 remains at least partially filled with oil even after a relatively long standstill period, so that wear-reducing oil filling of all toothings of the transmission 38 begins as soon as possible after the restart of the drive.

[0058] Fig.10 The diagram shows the flow through the normal operation, which is referred to here as strong flow operation. Fig. 9 A cross section of the oil container 44. In particular, the inner side of the container wall of the oil container 44 is shown in the viewing direction from the engine chamber. The inlet opening 98 transitions into the inlet channel 104, which is oriented approximately vertically. Its channel wall opposite the inlet opening 98 is configured as a concavely curved baffle 106, against which the oil thrown in during strong flow operation collides and flows downward with a relatively strong flow. Only a small part of this main flow of oil flows away through the channel opening 108 in the baffle 106, which will be discussed further below. The main part of the oil flow flows around the lower free end 110 of the baffle 106 and rises again thereafter. In particular, when a pressure corresponding to Fig.10 In the case of an oil level of the upper dashed oil level line, the oil can flow outwards through the rotor shaft outlet 48 in the wall of the oil container 44 and via correspondingly connected lines into the interior of the hollow rotor shaft 34, as already described. Figure 1 At the same time, oil can reach the transmission oil pan 46 via the transmission oil pan outlet 100 and the drive pinion groove 102. Only the outlet-free recess 112 below the transmission oil pan outlet 100 permanently provides an oil pan inside the container, which is particularly suitable for separating dirt. Fig.10 The dashed level line in the lower center shows the oil level in the oil container 44 after maximum draining.

[0059] Fig.11 Shows the Fig.10The same cross section through the oil container 44 is not, however, in the case of strong flow operation, but in the case of very slow operation of the drive device 10 or in the weak flow operation immediately after its start. The oil flow is correspondingly smaller, such as by Fig.11 Medium relative Fig.10 As shown by the modified oil delivery arrow. The oil that is only delivered in a trickle or droplet does not reach the baffle 106, but flows out at the channel wall opposite it. Below the inlet opening 98, the channel wall is therefore equipped with an oil guide flange 114, which ends obliquely above the channel 108, so that the oil dripping or flowing down at its edge flows through the above-mentioned channel 108 to the back of the baffle 106. There it is collected by the groove-shaped intermediate plate (or called cross plate, i.e. Zwichenboden) 116, which guides it directly to the rotor shaft outlet 48. This means that the oil filling of the rotor shaft inner cavity can be achieved in the case of a very small and slow oil flow without waiting for the previously described rise of the oil level around the lower free end 110 of the baffle 106. For the sake of completeness, the exhaust opening 118 at the upper part of the container 44 in any possible oil level during normal operation should also be pointed out.

[0060] Fig.12 A section through the oil container 44 is also shown, but with a view into the engine chamber 14. Two bearing outlets 120 of different sizes are arranged immediately above the intermediate plate 116 and an emergency outlet 122 to the engine chamber 14 is arranged further above. The bearing outlets 120 at the indicated positions ensure that, in addition to rotor shaft cooling, lubrication of the main bearings, which are connected to the bearing outlets 120 via an oil guide system (not shown in detail), is also ensured, even in the case of slow operation or immediately after starting the drive device 10.

[0061] Of course, the embodiments discussed in the detailed description and shown in the drawings are merely illustrative embodiments of the invention. A wide range of possible variations is provided to the skilled person in view of the disclosure herein.

[0062] List of reference numerals:

[0063] 10. Drive device

[0064] 12. Housing

[0065] 14 Engine cavity

[0066] 16 Transmission cavity

[0067] 18 inner end wall

[0068] 20 Outer end wall of engine chamber 14

[0069] 22 Outer end wall of the transmission chamber 16

[0070] 24 The casing wall of the engine chamber 14

[0071] 26 Housing wall of transmission chamber 16

[0072] 28 Motor

[0073] 30 Stator

[0074] 32 Rotor

[0075] 34 Rotor shaft

[0076] 36 Drive shaft

[0077] 38 Transmission

[0078] 40 Drive pinion

[0079] 42 Output gear

[0080] 44 Oil Container

[0081] 46 Transmission oil pan

[0082] 48 Rotor shaft outlet

[0083] 50 steps

[0084] 52 Radial opening of rotor shaft

[0085] 54 Stator winding head

[0086] 56 Cooling water jacket

[0087] 58 Labyrinth Cavity

[0088] 60 Engine cavity outflow

[0089] 62 Engine chamber overflow

[0090] 64 Air Gap

[0091] 66 Heat sink

[0092] 68 Labyrinthine cavity overflow

[0093] 70 Bottom of the labyrinth

[0094] 72 Oil guide element

[0095] 74 Suction chamber

[0096] 76 Oil Pump

[0097] 78 Oil distribution channel

[0098] 78a The first branch of 78

[0099] 78b The second branch of 78

[0100] 80 Cover cavity

[0101] 82 Additional engine chamber overflow

[0102] 84 Labyrinthine cavity overflow

[0103] 85 Narrowing barrier

[0104] 86 Ring Magnet

[0105] 88 oil pipe

[0106] 90 Fastening Star

[0107] 92 pipe joint

[0108] 94 Busbar

[0109] 96 nozzle opening

[0110] 98 Inlet of oil container 44

[0111] 100 Transmission oil pan outlet

[0112] 102 Drive pinion slot

[0113] 104 Entryway

[0114] 106 Baffle

[0115] 108 Channel 106

[0116] 110 106 free end

[0117] 112 Recess

[0118] 114 Oil guide flange

[0119] 116 Intermediate plate

[0120] 118 Exhaust opening

[0121] 120 Bearing outlet

[0122] 122 Engine compartment (emergency) exit.

Claims

1. A drive device (10) for a motor vehicle, comprising: - a housing (12) with an engine cavity (14) and a transmission cavity (16) adjacent to the engine cavity (14) separated from the engine cavity by an inner end wall (18), respectively limited by the inner end wall (18), an associated outer end wall and a casing wall extending in the axial direction between the inner end wall and the associated outer end wall, - an electric motor (28) arranged in the engine cavity (14), comprising a stator (30) fixed to a housing and a rotor (32) arranged radially inside the stator (30), the rotor having a rotor shaft (34) passing through the inner end wall (18) and rotatably supported in the engine cavity (14), and a transmission (38) arranged in the transmission chamber (16) with an input pinion (40) fastened to the rotor shaft (34) serving here as a drive shaft (36) and an output gear (42) connectable or connected to the driven end, and an oil reservoir, from which oil can be conducted via an oil supply system to the electric motor (28) for cooling purposes and from which oil can be conducted back into the oil reservoir via an oil discharge system, in, The housing wall (24) of the engine chamber (14) has a cooling water jacket (56) surrounding the stator (30) along the circumference of the stator for additional cooling of the electric machine (28). and wherein at least a portion of the oil reservoir is configured as an oil chamber arranged below the engine chamber (14), the upper side of which is thermally coupled to the cooling water jacket (56) and an engine chamber outflow portion (60) opening into the oil chamber is arranged in each axial end region of the engine chamber (14) close to the end wall, It is characterized in that The oil chamber is constructed as a labyrinth chamber (58) and is provided with a cover chamber (80) axially adjacent to the outer end wall (20) of the engine chamber (14). The cover chamber is connected to the labyrinth chamber (58) via a second labyrinth chamber overflow (84), wherein a second engine chamber overflow (82) is present in the outer end wall (20) of the engine chamber (14), the oil can reach the cover chamber (80) from the engine chamber (14) via the second engine chamber overflow, and the second engine chamber overflow is arranged to be higher than the engine chamber outflow (60).

2. The drive device (10) according to claim 1, characterized in that: The underside (70) of the labyrinth chamber (58) is an outer wall region of the drive device.

3. The drive device (10) according to claim 1 or 2, characterized in that: The outer side of a housing wall (24) of the engine chamber (14) has cooling fins (66) in a boundary region relative to the labyrinth chamber (58) and projecting into the labyrinth chamber (58) and around which flow can flow.

4. The drive device (10) according to claim 1 or 2, characterized in that: The rotor shaft (34) is hollow in design and oil can be conducted into the hollow rotor shaft (34) via the oil supply system and can be conducted from the hollow rotor shaft (34) into the oil reservoir via the oil discharge system.

5. The drive device (10) according to claim 4, characterized in that The hollow rotor shaft (34) has a radial opening (52) in the engine chamber (14) in its axial end region close to the end wall, and when the rotor (32) rotates, oil can be thrown from the hollow interior of the rotor shaft (34) to the axial end region of the stator (30) through the radial opening.

6. The drive device (10) according to claim 1, characterized in that: The two engine chamber outflows (60) open into a common labyrinth chamber.

7. The drive device (10) according to claim 1, characterized in that: The labyrinth chamber (58) has two separate labyrinth chambers, into which each of the two engine chamber outflows (60) opens.

8. The drive device (10) according to claim 6 or 7, characterized in that: The labyrinth (58) has a first labyrinth overflow (68) to the transmission oil sump in a lower region of the transmission chamber (16).

9. The drive device (10) according to claim 6 or 7, characterized in that: Each labyrinth chamber is fluidly connected to a suction chamber (74) of an oil pump (76).

10. The driving device (10) according to claim 1 or 2, characterized in that: The engine chamber (14) has a first engine chamber overflow (62) extending through the inner end wall (18) to a transmission oil sump (46) in a lower region of the transmission chamber (16), which is arranged higher than the engine chamber outflow (60).

11. The drive device (10) according to claim 1, characterized in that Oil can be conducted from the oil reservoir via an oil supply system to the rotor shaft (34) for cooling.

Images