DRIVE DEVICE FOR AN ELECTRIFIED VEHICLE AXLE

Description

[0001] The invention relates to a drive device for an electrified vehicle axle of a vehicle according to the preamble of claim 1.

[0002] An electrified vehicle axle of a two-track, electrically powered vehicle has an electric motor that drives via a transmission to drive shafts that lead to the vehicle wheels of the vehicle axle. The vehicle axle also has an oil supply system with an oil module that supplies oil to the electric motor and the transmission.

[0003] In an exemplary drive system, the oil module, the electric motor, and the transmission are combined into a single unit. Within the unit, the oil module is flanged to the transmission at a joining plane. Furthermore, the oil module supplies both the transmission and the electric motor with oil via supply lines. The oil is fed from the electric motor and the transmission back to the oil module via return lines.

[0004] In the current state of the art, the supply lines and the return lines are installed as separate line elements in the oil supply system in a complex manner.

[0005] DE 10 2010 041 415 A1 discloses a composite transmission housing assembly. DE 103 05 781 B4 discloses a multi-stage lubricating oil pump. DE 101 43 929 A1 discloses a transmission control device.

[0006] US 2013 / 145879 A1 discloses a drive device of this type. An electric transmission is known from US 2013 / 019707 A1.

[0007] The object of the invention is to provide a drive device for an electrified vehicle axle of a vehicle, the oil supply system of which can be manufactured with reduced component expenditure compared to the prior art.

[0008] The object is solved by the features of claim 1. Preferred developments of the invention are disclosed in the subclaims.

[0009] The invention is based on a drive device for an electrified vehicle axle of a vehicle, which has an electric motor, a transmission, and an oil module. The oil module supplies the electric motor and the transmission with oil. Furthermore, the electric motor, the transmission, and the oil module are combined to form a single structural unit. In the structural unit, the oil module is flanged to the transmission at a joining plane. The oil module supplies the electric motor and the transmission with oil via at least one supply line. According to the characterizing part of claim 1, the supply line is not installed as a separate line element, but rather is designed as a channel that runs in the joining plane between the oil module and the transmission. The channel is constructed from a module-side channel segment and a transmission-side channel segment. The two channel segments together define a channel cross-section through which oil flows.

[0010] In one technical implementation, the oil module has a module housing on which a pump unit, a heat exchanger, an oil filter, and an oil tank are formed or mounted. These are components of an oil supply system in which the electric motor and / or the transmission are each integrated into a hydraulic circuit in which oil is circulated. The module housing and the transmission housing can be formed as metal castings. In this case, the module-side channel segment can be formed from the same material and / or integrally onto the module housing. Similarly, the transmission-side channel segment can be formed from the same material and / or integrally onto the transmission housing.

[0011] For the functionality of the oil supply system, a sufficiently large channel cross-section of the channel integrated between the module housing and the gearbox housing is crucial. For this reason, the module-side channel segment and / or the gearbox-side channel segment can have a channel base that is recessed relative to the joining plane, from which channel walls extend upwards toward the joining plane to a contact surface. In the assembled state, the mutually facing contact surfaces of the channel segments can be in a sealed arrangement. The sealing arrangement can be designed to be largely oil-tight. Minor oil leakage may occur between the contact surfaces of the channel segments if necessary.

[0012] At the joining plane, a particularly shell-shaped module housing wall and a particularly shell-shaped transmission housing wall can define an intermediate space in which the channel according to the invention runs. The module housing wall and the transmission housing wall can be connected to one another at the joining plane by a circumferential flange connection. Housing flanges of the module housing and the transmission housing are connected to one another at the flange connection, optionally with the interposition of a sealing element. In this way, the intermediate space can be hermetically sealed to the outside in an oil-tight manner. Leakage oil escaping from the channel can therefore collect in the intermediate space at the bottom and from there be returned to the oil module via a return point. This eliminates the need for a technically complex hermetic oil seal for the channel.

[0013] In a specific embodiment, an electric machine supply line can be routed from a pump unit of the oil module to the electric machine. In common practice, a heat exchanger and an oil filter can be arranged in the electric machine supply line. In this case, the electric machine supply line can be divided into a first sub-line extending between the pump unit and the heat exchanger inlet, a second sub-line extending between the heat exchanger outlet and the oil filter inlet, and a third sub-line extending between the filter outlet and the electric machine. The heat exchanger can be attached externally to a module housing mounting surface. In contrast, the oil filter and the pump unit can be arranged in a hollow cylindrical housing section of the module housing. The oil tank can also be formed from the same material and integrally in the module housing.

[0014] The above first sub-line can be designed as a channel according to the invention. This can be in flow communication with the heat exchanger inlet located outside the housing via a channel opening formed in the module housing wall. The second sub-line can also be designed as a channel. This can be in flow communication with the heat exchanger outlet, also located outside the housing, via a channel opening in the module housing wall. Furthermore, the channel (forming the second sub-line) can open into the oil filter at another channel opening.

[0015] In another specific embodiment, a transmission supply line can be routed from the pump unit to the transmission. The transmission supply line can be designed at least partially as a channel according to the invention. Furthermore, the pump unit can be designed as a multi-stage pump with a common drive shaft, the stages of which function both as a pressure pump and as a suction pump.

[0016] An embodiment of the invention is described below with reference to the attached figures.

[0017] They show: Fig. 1 shows a block diagram of a drive device for an electrified vehicle axle of a vehicle; Fig. 2 shows a perspective sketch of the drive device; Figs. 3a and 3b each show a module housing wall ( Fig. 3a ) and a cooperating gearbox housing wall ( Fig. 3b); Fig. 4a and 4b are rough schematic views of the module housing wall and the gearbox housing wall in the assembled state ( Fig. 4a ) and in disassembled condition ( Fig. 4b ).

[0018] In the Figure 1 A simplified block diagram shows a drive device for a vehicle axle of a two-track vehicle. The vehicle axle has an electric motor 1, which is arranged transversely and axially parallel to the drive shafts 3, 4 leading to the vehicle wheels. The rotor shaft 5 of the electric motor 1 is connected to the two drive shafts 3, 4 via a gear 7. Figure 1The transmission 7 has a double spur gear stage, which is in driving connection with an input-side gear 9 of an axle differential 11. The axle differential 11 drives on both sides onto the drive shafts 3, 4 leading to the vehicle wheels. In addition, the drive device has an oil module 13, the structure of which is described below only to the extent necessary for understanding the invention. Accordingly, the oil module 13 has an oil tank 15, which is connected to a multi-stage pump 17 via a suction line. An electric machine supply line 21 leads from the multi-stage pump 17 to the electric machine EM in order to supply it with oil. Oil is sucked from the electric machine EM towards the multi-stage pump 17 via a return line. A heat exchanger 22 and an oil filter 24, which are also components of the oil module 13, are arranged in the electric machine supply line 21.

[0019] As from the Figure 1As can be seen further, the electric machine supply line 21 is divided into a first sub-line 16, a second sub-line 18, and a third sub-line 20. The first sub-line 16 connects a pump outlet 26 to a heat exchanger inlet 28; the second sub-line 18 connects the heat exchanger outlet 30 to the oil filter inlet 32, while the third sub-line 20 connects the oil filter outlet 34 to the electric machine 1.

[0020] In addition, a transmission supply line 19 leads from the multi-stage pump 17 to the transmission 7. Oil is supplied to the gear meshing points of the transmission 7 via the transmission supply line 19. The oil drips from the gear meshing points, collects in an oil sump, and from there is sucked toward the multi-stage pump 17 via another return line.

[0021] In the Figure 2The electric motor 1, the transmission 7, and the oil module 13 are combined into a single structural unit. Within the structural unit, the electric motor 1 and the oil module 13 are arranged axially parallel and spaced apart from each other by an axial distance Δx. Furthermore, the electric motor 1 and the oil module 13 are flange-mounted to the transmission 7 via flange connections 27, 29. Power electronics 31 (indicated by a dotted line) is assigned to the electric motor 1. This power electronics unit is located on the top side of the structural unit.

[0022] The oil module 13 has in the Figure 2 or 3a module housing 33, which is designed as a cast component, to which the multi-stage pump 17, the heat exchanger 22, and the oil filter 24 are mounted. The oil tank 15 is integrated in the module housing 33 as an annular space (not shown), which defines a shaft passage 35 in the module housing 33. A drive shaft 3, 4 (not shown) is guided through the shaft passage 35 from the transmission 7 to one of the vehicle wheels.

[0023] According to the Figure 2 The gear housing 37 is constructed in two parts with an intermediate housing 39 and a housing cover 41. The intermediate housing 39 is positioned in the axial direction between the module housing 33 and the housing cover 41. At a joining plane F ( Figure 4a ) is the module housing 33 with a shell-shaped module housing wall 43 in flange connection 29 with a likewise shell-shaped gear housing wall 45 of the intermediate housing 39, in the interior 40 of which the Figure 1shown gear components are arranged. Between the module housing wall 43 and the gear housing wall 45, an intermediate space 47 is defined, which is hermetically sealed to the outside of the housing by means of the circumferential flange connection 29. By way of example, in the Figure 4a a sealing element 36 is arranged between the housing flanges of the flange connection 29.

[0024] A core of the invention is that the supply lines 19, 21 are at least partially designed as channels running in the joining plane F between the oil module 13 and the transmission 7. Each of these channels is according to the Figure 4a and 54b are constructed from a module-side channel segment 49 and a transmission-side channel segment 51. The two channel segments 49, 51 limit in the Figure 4aa channel cross-section through which oil flows. Furthermore, the module-side channel segment 49 is formed integrally and from the same material onto the module housing wall 43, while the transmission-side channel segment 51 is formed integrally and from the same material onto the transmission housing wall 45.

[0025] According to the Figures 3a and 3b The first and second sub-lines 16, 18 of the electric machine supply line 21 are implemented as such channels. Similarly, the transmission supply line 19 is also implemented as a channel.

[0026] Each of the channel segments 49, 51 has a channel base 53 which is set back with respect to the joining plane F, from which channel walls 55 are raised in the direction of the joining plane F up to a contact surface 57. In the assembled state ( Figure 4a ) the contact surfaces 57 of the two channel segments 49, 51 facing each other are in sealed contact. For example, in the Figure 4athe course of the first partial line 16 is shown. Accordingly, the first partial line 16 leads from the pump outlet 26 via the first partial line 16 designed as a channel to a channel opening 59, which establishes a flow connection with the heat exchanger inlet 28 of the heat exchanger 22 arranged on the outside of the module housing wall 43. The second partial line 18 is according to the Figure 4a also designed as a channel which is in flow connection with the heat exchanger outlet 30 at a channel opening 61 and opens into the oil filter 24 at a further channel opening (not shown).

[0027] According to the Figure 4a the contact surfaces 57 of the channel segments 49, 51 and the contact surfaces 63 of the circumferential flange connection 29 are arranged in the same joining plane F.

[0028] As from the Figure 4aAs can be seen, leakage oil L can escape from the partial line 16, which is implemented as a channel. The leakage oil L escaping from the channel can collect in the space 47 on the bottom side and is returned from there to a suction point A in the direction of the oil module 13. LIST OF REFERENCE SYMBOLS:

[0029] 1 Electric machine 3, 4 Drive shafts 5 Rotor shaft 7 Gearbox 9 Input gear 11 Axle differential 13 Oil module 15 Oil tank 16 First sub-line 17 Multiple pump 18 Second sub-line 19 Gearbox supply line 20 Third sub-line 21 Electric machine supply line 26 Pump outlet 27 Flange connection 28 Heat exchanger inlet 29 Flange connection 30 Heat exchanger outlet 31 Power electronics 32 Oil filter inlet 33 Module housing 34 Oil filter outlet 36 Sealing element 37 Gearbox housing 39 Intermediate housing 40 Interior of the intermediate housing 41 Housing cover 43 Module housing wall 45 Gearbox housing wall 47 Intermediate space 49 Module-side channel segment 51 Housing-side channel segment 53 Channel base 55 Channel walls 57Contact surface 59, 61Channel openings 63Contact surfaces of the flange connection 29 AExtraction point FJoining plane LLeakage oil ΔxAxial distance

Claims

1. Drive device for an electrified vehicle axle of a vehicle, with an electric machine (1), which outputs via a transmission (7) to drive shafts (3, 4), which are guided to vehicle wheels of the vehicle axle, and with an oil module (13), which supplies the electric machine (1) and / or the transmission (7) with oil, wherein the electric machine (1), the transmission (7) and the oil module (13) are combined to form a unit, in which the oil module (13) is flanged at a joining plane (F) onto the transmission (7), wherein the oil module (13) supplies the electric machine (1) and / or the transmission (7) with oil via at least one supply line (19, 21) and the oil can be returned from the electric machine (1) and / or from the transmission (7) via at least one return line to the oil module (13), characterized in that the supply line (19, 21) and / or the return line is at least partly configured as a channel extending in the joining plane (F) between the oil module (13) and transmission (7), which channel is constructed from a module-side channel segment (49) and a transmission-side channel segment (51), which together delimit channel cross-section through which oil flows.

2. Drive device according to claim 1, characterized in that the oil module (13) has a module housing (33), on which a pump unit (17), a heat exchanger (22), an oil filter (24) and / or an oil tank (15) are configured or mounted, and / or in that the module housing (33) and a transmission housing (37) are configured as cast parts, and / or in that in particular the module-side channel segment (49) and the transmission-side channel segment (51) are each formed from the same material and / or integrally on the module housing (33) and on the transmission housing (37).

3. Drive device according to claim 1 or 2, characterized in that the module-side channel segment (49) and / or the transmission-side channel segment (51) have a channel base (53) that is set back relative to the joining plane (F), from which channel base channel walls (55) rise up in the direction of a joining plane to a contact surface (57) and / or in that in the assembled state contact surfaces (57) of the channel segments (49, 51) are in sealing engagement.

4. Drive device according to claim 2 or 3, characterized in that at the joining plane (F) a module housing wall (43), which is shell-shaped in particular, and a transmission housing wall (45), which is shell-shaped in particular, define an intermediate space (47), in which the channel extends, and in that the module housing wall (43) and the transmission housing wall (45) are connected to one another by a circumferential flange connection (29), which seals off the intermediate space (47) from the outside in an oil-tight manner.

5. Drive device according to claim 4, characterized in that the contact surfaces (57) of the channel segments (49, 51) and the contact surfaces (63) of the flange connection (29) lie jointly in the joining plane (F).

6. Drive device according to claim 4 or 5, characterized in that leakage oil (L) exiting the channel collects on the bottom in the intermediate space (47) and can be returned from there via a return point (A) to the oil module (13).

7. Drive device according to any one of claims 2 to 6, characterized in that an electric machine supply line (21) is guided from the pump unit (17) of the oil module (13) to the electric machine (1), and in that the heat exchanger (22) and the oil filter (24) are arranged in the electric machine supply line (21), and in that in particular the electric machine supply line (21) is divided into a first partial line (16) between the pump unit (17) and the heat exchanger inlet (28), a second partial line (18) between the heat exchanger outlet (30) and the oil filter inlet (32), and / or a third partial line (20) between the filter outlet (34) and the electric machine (1), and / or in that the heat exchanger (22) is arranged on the outside of the module housing (33).

8. Drive device according to claim 7, characterized in that the first partial line (16) is configured as a channel which is in flow connection with the heat exchanger inlet (28) at a channel opening (59) formed in the module housing wall (43).

9. Drive device according to claim 7 or 8, characterized in that the second partial line (18) is configured as a channel, which is in flow connection with the heat exchanger outlet (30) at a channel opening (61) formed in the module housing wall (43) and opens into the oil filter (24) at a further channel opening.

10. Drive device according to any one of claims 2 to 9, characterized in that a transmission supply line (19) is guided from the pump unit (17) to the transmission (7), and in that in particular the transmission supply line (19) is configured at least partly as a channel, and / or in that the pump unit (17) is configured as a multi-stage pump with a common drive shaft, the stages of which operate as a pressure pump and as a suction pump.