Power equipment for axles

Abstract

The present invention relates to a power unit for an electrified axle of a vehicle, comprising an electric motor (EM) and a cooling / lubricating module (13), wherein the electric motor drives flange shafts (3, 4) leading to wheels via a transmission (7), and the cooling / lubricating module supplies cooling / lubricating medium to the electric motor (EM) and / or the transmission (7). According to the present invention, the power unit has a modular housing structure, wherein the module housing (33) of the cooling / lubricating module (13), the stator housing (2) of the electric motor (EM), and the transmission housing (6) are assembled into a component as mutually independent metal castings, in particular die-castings.

Description

Technical Field

[0001] The invention relates to a power unit for an electrified axle of a two-track vehicle according to the preamble of claim 1 . Background Art

[0002] An electrified axle for a two-track motor vehicle has an electric motor that drives a flanged shaft to each wheel via a transmission. The electric motor and the transmission are components of a drive unit of this type, which is supported, for example, on a subframe of the vehicle body via a three- or four-point support.

[0003] Power plants of this type have a space-consuming housing structure, the housing parts of which can be die-cast to a limited extent due to their complex component geometry.

[0004] DE 10 2019 112 677 A1 discloses a hydraulic supply system for a vehicle. DE 10 2019 205 758 A1 discloses a transmission arrangement for a motor vehicle. DE 10 2019 218 982 A1 discloses a power unit for a hybrid vehicle. Summary of the Invention

[0005] The object of the present invention is to provide a power device for an electrified axle of a two-track vehicle, the housing structure of which is designed to be more compact than that of the prior art and easier to manufacture.

[0006] This object is achieved by the features of claim 1. Preferred developments of the invention are disclosed in the dependent claims.

[0007] The invention is based on a power unit having an electric motor which drives a flange shaft leading to a wheel via a transmission. The power unit also has a lubricating medium module and / or a cooling medium module which supplies cooling / lubricating medium to the electric motor and / or the transmission. According to the characterizing portion of claim 1, the power unit has a modular three-part housing structure, wherein the module housing, the stator housing of the electric motor and the transmission housing are provided as metal castings, in particular die castings, which are independent of one another and are assembled to form a power unit / powertrain. The housing components of the power unit each have a castable component geometry. In addition, the housing components, i.e. the stator housing, the transmission housing and the module housing, are assembled to form a more compact structural unit compared to the prior art.

[0008] In one technical implementation, the stator housing can be flange-connected to the transmission housing via a flange connection. The stator housing and transmission housing can define an inner angular region within which the module housings of the coolant and / or lubricant modules can be positioned in a space-saving manner. In the assembled state, the stator housing and the flange shaft are spaced axially apart. For a compact design of the assembly, it is preferred that the module housing include a shaft passage through which one of the flange shafts passes. In this case, the oil tank in the module housing can be designed as an annular space extending around the flange shaft.

[0009] To facilitate assembly and disassembly, the transmission housing can consist of two housing parts that can be arranged axially one behind the other. In this case, the transmission housing comprises an intermediate housing and a housing cover. Both the stator housing and the module housing can be flange-connected to one side of the intermediate housing. The housing cover can be flange-connected to the axially opposite side of the intermediate housing and seal the interior of the transmission housing.

[0010] In the assembled state, the stator housing and the module housing are spaced apart from each other in the axial direction. In order to avoid component vibrations during driving operation, it is preferred that the stator housing and the module housing, in particular on the side facing away from the transmission, are connected to each other in a force-transmitting manner via a support component.

[0011] In a specific embodiment variant, the electric motor can be mounted transversely in the axle. In this case, the stator housing of the electric motor can be axially extended by the transmission housing in the transverse direction of the vehicle. The powertrain assembly can also be supported in the vehicle body in a three-point manner via a total of three assembly supports.

[0012] According to the present invention, the module housing is positioned adjacent to the stator housing. The module housing contains the oil for dry sump lubrication. It also houses the oil lines and components connected to the oil circuit, namely the oil-to-water heat exchanger, oil filter, and oil pump. This invention achieves a housing structure that is lower in height and more efficient (i.e., reduces oil churning losses in rotating components) compared to the prior art.

[0013] Since the power electronics are arranged on the upper side of the assembly, all assembly supports can be positioned laterally on the intermediate housing, the transmission cover and the stator housing. In addition, when the power electronics are arranged on the upper side of the assembly, no force is transmitted to sensitive components within the power electronics (i.e. the pulse inverter). The power assembly according to the invention can be tested and assembled as a module. Due to its compact design, the power assembly is suitable for installation on the front and rear axles. In addition, the reaction forces from the power unit are introduced directly from the motor support into the housing, so that no screw connection surfaces are required and the lever arms are smaller (so that the reinforcement ribs can be made smaller). Compared to the transmission housing and the module housing, the stator housing can be made of other aluminum alloys with higher ductility. As a result, it is no longer necessary to use expensive alloys in areas where higher ductility is not required for design reasons.

[0014] Due to the compact design of the powertrain, the enclosed space associated with the package is small and well-utilized. Consequently, there is virtually no unused surrounding space. The use of support components between the stator housing and the module housing improves the acoustics during driving. Without support components, the torque variations in the transmission and the resulting support forces on the bearings would cause vibrations. The support components, acting as shear-resisting / shear-bearing components, effectively reduce these effects in the vertical and lateral directions, significantly improving the acoustics. At the same time, installation in the vehicle's longitudinal direction is unimpeded, and length tolerances can be effectively compensated.

[0015] According to the compact construction method of the present invention, an approximately cubic package geometry is produced. In addition, the modular construction also has advantages with regard to the installation sequence: the subassemblies can be pre-assembled in parallel before being assembled into the power assembly. In addition, accessibility during the installation process is ensured. In addition, the subunits can be tested before being assembled into the power assembly, thereby ensuring quality. In addition, the housing construction according to the present invention provides a high degree of integration into each individual construction (oil module, intermediate housing). Therefore, oil lines for pressure / suction oil can be integrated. The individual housings can also be designed to be suitable for casting. The housing structure according to the present invention also obtains high rigidity, because shear-resistant components can be formed in the transmission mechanism housing and the intermediate housing for the gear bearings with high loads.

[0016] For smooth operation, operationally reliable torque support of the reaction forces is crucial. For this purpose, the three-point support can have two component supports on the transmission side, via which the transmission housing is supported in the vehicle body. The two component supports on the transmission side are arranged on opposite sides relative to the flange shaft axis in the longitudinal direction of the vehicle, thereby providing torque support in both flange shaft rotational directions.

[0017] In one technical implementation, the housing cover and the intermediate housing can each have a support wall. The support wall of the housing cover and the support wall of the intermediate housing are arranged axially opposite each other in the transverse direction of the vehicle. In addition, each support wall has a support portion for the transmission shaft and the flange shaft. To achieve stable rotational support of the transmission shaft and the flange shaft, the housing cover and the intermediate housing are designed to have corresponding rigid components. In order to achieve reliable support for the power assembly in operation, it is preferred that the first component support on the transmission side of the two component supports on the transmission side is formed on the housing cover, while the second component support on the transmission side is formed on the intermediate housing. Unlike the two component supports on the transmission side, the third component support is formed directly on the stator housing to support its component weight reliably in operation.

[0018] To ensure problem-free rotational support of the transmission and flange shaft, the bearing walls of the housing cover and intermediate housing are designed to provide component rigidity with appropriate material costs. In a preferred embodiment, the first component support on the transmission side can be located in the plane of the bearing wall of the housing cover, while the second component support on the transmission side can be located in the plane of the bearing wall of the intermediate housing. In this way, the bearing walls of the housing cover and intermediate housing also perform the dual function of serving as shear elements, allowing reaction forces to be introduced into the shear elements without deformation during driving operation, thereby achieving extremely rigid torque support.

[0019] Since both component supports are designed directly on the transmission housing, the lateral offset (lever arm length) of the axle differential when viewed in the transverse direction of the vehicle is relatively small. This makes it easy to avoid, for example, bending or twisting of the powertrain component due to introduced reaction forces in the design.

[0020] In a structurally simple embodiment, each assembly support can be designed as a rubber metal sleeve support that is pressed into a fastening hole in the transmission housing and / or stator housing. The fastening hole can be integrally formed on the transmission housing or the stator housing using a uniform material. To achieve particularly effective torque support, it is preferred that the bearing axes of the two assembly supports on the transmission side, and in particular also the bearing axis of the assembly support on the stator housing side, are parallel to each other relative to the flange shaft axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0022] In the attached figure:

[0023] Figure 1 A block diagram showing a power plant for an electrified axle of a vehicle;

[0024] Figure 2A cross-sectional view showing a power assembly;

[0025] Figure 3 A schematic diagram showing the housing structure of the power assembly. DETAILED DESCRIPTION

[0026] exist Figure 1 The simplified block diagram in FIG shows the power plant for the axle of a two-track vehicle. The axle has an electric motor EM, which is arranged in a transverse manner with its axis parallel to the flange shafts 3 and 4 leading to the wheels. The rotor shaft 10 of the electric motor EM is connected to the two flange shafts 3 and 4 through a transmission mechanism 7. Figure 1 In the embodiment, the transmission 7 has a double spur gear stage which is drivingly connected to the input-side gear 9 of the axle differential 11. The axle differential 11 drives the flange shafts 3, 4 leading to the wheels on both sides.

[0027] The power plant also has an oil module 13, the structure of which will be described below only to the extent necessary for an understanding of the present invention. The oil module 13 comprises an oil tank 15, which is connected to a multi-pump 17 via a suction line. A motor supply line 21 leads from the multi-pump 17 to the electric motor EM in order to supply it with oil. The oil is drawn from the electric motor EM via a return line toward the multi-pump 17. A heat exchanger 22 and an oil filter 24, also components of the oil module 13, are located in the motor supply line 21.

[0028] Furthermore, a transmission supply line 19 leads from the multipump 17 to the transmission 7. Oil is supplied to the tooth meshing of the transmission 7 via the transmission supply line 19. The oil drips from the tooth meshing, collects in an oil sump, and is sucked from there via another return line toward the multipump 17.

[0029] exist Figure 2 or Figure 3 In the embodiment, the motor EM, the transmission mechanism 7 and the oil module 13 are combined into a power assembly. In the power assembly, the motor EM and the oil module 13 are arranged in parallel with their axes and are spaced apart from each other by an axial distance Δx ( Figure 2 The electric motor EM has a cylindrical stator housing 2, which is axially extended in the vehicle transverse direction y by the transmission housing 6. Furthermore, the stator housing 2 of the electric motor EM and the module housing 33 of the oil module 13 are flange-connected to the transmission 7 via flange connections. Figure 3 Schematically shows the housing structure of the power pack in a top view. Accordingly, the electric motor 1 is assigned a power electronic device 31 (indicated by a dotted line). The power electronic device is located on the upper side of the power pack.

[0030] The oil module 13 has Figure 2 or Figure 3The module housing 33 in the transmission housing 6 and the stator housing 2 is similar to the module housing 33, which is designed as a casting component. The multi-pump 17, the heat exchanger 22 and the oil filter 24 are mounted on the module housing 33. The oil tank 15 is used as Figure 2 The annular space shown ( Figure 2 ) is integrated in the module housing 33, and the annular space defines a shaft passage 35 in the module housing 33. The flange shaft 3 passes through the shaft passage 35 from the transmission mechanism 7 to one of the wheels.

[0031] In addition, Figure 2 As shown, the stator housing 2 and the module housing 33 are connected to one another in a force-fitting manner on their side facing away from the gear mechanism via a support element 58 , by means of which component vibrations can be reduced.

[0032] according to Figure 2 or Figure 3 The transmission housing 6 is constructed in two parts and has an intermediate housing 39 and a housing cover 41. The intermediate housing 39 is positioned between the module housing 33 and the housing cover 41 in the axial direction.

[0033] The spur gear stage and the axle differential 11 are both arranged in the transmission housing 6. The housing cover 41 closes the transmission interior space 30 ( Figure 2 ).exist Figure 2 In the figure, the transmission interior space 30 is axially delimited in the vehicle transverse direction y by a support wall 46 of the intermediate housing 39 and a support wall 48 of the housing cover 41. The support wall 46 of the intermediate housing 39 has a support opening 44 in which the rotor shaft 10 of the electric motor EM is rotatably supported. Furthermore, the support wall 46 of the intermediate housing 39 has a shaft passage 35 in which the left flange shaft 3 is rotatably supported. Furthermore, the support wall 46 of the intermediate housing 39 is configured as a rotational bearing for the transmission intermediate shaft 52. The support wall 48 of the housing cover 41 has two support openings for the transmission input shaft 12 and the transmission intermediate shaft 52, as well as a shaft passage 47 in which the right flange shaft 4 is rotatably supported.

[0034] Figure 3 The power assembly is supported on a roughly schematically shown subframe 57 in a three-point supporting manner using a total of three assembly supports 53, 54, 55. The subframe 57 has Figure 3 The two lateral subframe longitudinal members are connected to the subframe cross member at the front and rear of the vehicle respectively.

[0035] The three-point support structure has two component supports 53, 54 on the transmission side, via which the transmission housing 6 is supported on the auxiliary frame 57. The two component supports 53, 54 on the transmission side are aligned with respect to the flange shaft axis F ( Figure 2 ) are arranged on opposite sides in the longitudinal direction x of the vehicle, that is, at the front and rear of the vehicle. Figure 3 In the figure, the first assembly support 53 on the transmission side is connected to the rear subframe cross member, and the second assembly support 54 on the transmission side is connected to the front subframe cross member. The third assembly support 55 is arranged on the stator housing 2, thereby primarily supporting the electric motor EM. The center of gravity of the power assembly is located in the motor area.

[0036] During driving operation, reaction forces are introduced from the wheels via the flanged shafts 3, 4 into the axle differential 11 and from there into the rest of the drive train 1. To stably support the moment of the reaction forces, the two transmission-side assembly supports 53, 54 are positioned with a minimal transverse offset relative to the axle differential 11, as viewed in the vehicle transverse direction y.

[0037] like Figure 2 As shown, the component supports 53, 54, 55 are each designed as a rubber metal sleeve support. Therefore, each of the component supports 53, 54 shown has an inner sleeve-shaped support core 63, which is connected to an outer sleeve 67 via an elastomer 65. The radially inner support core 63 can be connected to a support bracket of the subframe 57 via a support pin (not shown). Figure 2 The bearing axes L of the two transmission-side assembly supports 53 , 54 and the stator housing-side assembly support 55 are all oriented in the vehicle transverse direction y.

[0038] As from Figure 3 As can be seen, the first assembly support 53 on the transmission side is formed on the housing cover 41. The first assembly support 53 on the transmission side lies in the same plane as the support wall 48 of the housing cover 41. Therefore, under load, the support wall 48 acts as a shear-resistant element that stiffens the component. Similarly, the second assembly support 54 on the transmission side is formed on the intermediate housing 39. The second assembly support 54 on the transmission side lies in the same plane as the support wall 46 of the intermediate housing 27. As a result, the support wall 46 of the intermediate housing 39 also acts as a shear-resistant element that stiffens the component under load.

[0039] Reference Signs List

[0040] 2 stator housing

[0041] 3, 4 flange shaft

[0042] 5 Rotor shaft

[0043] 6 Transmission mechanism housing

[0044] 7 Transmission mechanism

[0045] 9 Input gear

[0046] 10 rotor shaft

[0047] 11 Axle differential

[0048] 12 Transmission input shaft

[0049] 13 Oil module

[0050] 15 fuel tank

[0051] 17 Multiple Pumps

[0052] 19 Transmission supply line

[0053] 21 Motor supply line

[0054] 26 Pump outlet

[0055] 30 Transmission mechanism internal space

[0056] 31 Power Electronics

[0057] 32 Oil filter inlet

[0058] 33 Module housing

[0059] 34 Oil filter outlet

[0060] 35-axis channel

[0061] 39 intermediate shell

[0062] 41 Housing cover

[0063] 44 Support hole

[0064] 46 Support wall of intermediate housing 39

[0065] 47 axis channels

[0066] 48 Support wall of transmission mechanism cover 41

[0067] 49 rotor

[0068] EM motor

[0069] Δx axial distance

[0070] 52 intermediate shaft

[0071] 51 stator

[0072] 53, 54, 55 component supports

[0073] 57 Subframe

[0074] 58 Support components

[0075] 63 Internal support core

[0076] 65 Elastomer

[0077] 67 Outer sleeve

[0078] 69 fixing holes

[0079] L Support axis

[0080] F Flange shaft axis

Claims

1. A power unit for an electrified axle of a vehicle, comprising an electric motor (EM) and a cooling / lubricating module (13), wherein the electric motor drives flange shafts (3, 4) leading to wheels via a transmission (7), and wherein the cooling / lubricating module supplies cooling / lubricating medium to the electric motor (EM) and / or the transmission (7), wherein: The power device has a modular housing structure, wherein a module housing (33) of a cooling / lubrication module (13), a stator housing (2) of an electric machine (EM) and a transmission housing (6) are assembled into a component as independent metal castings.

2. The power equipment according to claim 1, characterized in that: The stator housing (2) is flange-connected to the transmission housing (6) via a flange connection. The stator housing (2) and the transmission housing (6) define an inner angle region, in which a module housing (33) is arranged, and / or the module housing (33) has a shaft passage (35) through which one of the flange shafts (3, 4) passes.

3. The power equipment according to claim 1 or 2, characterized in that: The transmission housing (6) has two housing parts arranged axially one after another, namely an intermediate housing (39) and a housing cover (41). The stator housing (2) and the module housing (33) are connected to a flange on one intermediate housing side, and the housing cover (41) is connected to the flange on the intermediate housing side opposite in the axial direction. The housing cover closes the internal space (40) of the transmission housing.

4. The power equipment according to claim 1 or 2, characterized in that: The stator housing (2) and the module housing (33) are spaced apart from each other by an axial distance (Δx) and are connected to each other in a force-transmitting manner on their side facing away from the transmission via a support component (58).

5. The power equipment according to claim 3, characterized in that: The electric motor (EM) is arranged in a transverse manner in the vehicle axle, the stator housing (2) of the electric motor (EM) is axially extended by the transmission housing (6) in the vehicle transverse direction (y), and / or the assembly is supported in the vehicle body by three assembly supports in a three-point manner.

6. The power equipment according to claim 5, characterized in that: The intermediate housing (39) and the housing cover (41) each have supporting walls (46, 48) which are axially opposed to each other, and the transmission shaft (10, 12, 52) and the flange shaft (3, 4) are rotatably supported in the supporting walls (46, 48) of the intermediate housing (39) and the housing cover (41).

7. The power equipment according to claim 5, characterized in that: The first assembly support (53) on the transmission side is formed on the housing cover (41), the second assembly support (54) on the transmission side is formed on the intermediate housing (39), and the third assembly support (55) is formed on the stator housing (2).

8. The power equipment according to claim 1 or 2, characterized in that: The power electronics (31) of the electric machine (EM) are arranged on the upper side of the assembly and at least partially cover the transmission housing (6), the module housing (33) and the stator housing (2).

9. The power equipment according to claim 5, characterized in that: Each component support (53, 54, 55) is designed as a rubber metal sleeve support, which is pressed into a fixing hole (69) of the transmission housing (6) and / or the stator housing (2), and the fixing holes of the component support (53, 54, 55) are formed in a uniform, integral manner on the stator housing (2), the intermediate housing (39) and the housing cover (41).

10. The power equipment according to claim 1 or 2, characterized in that: A pump unit (17), a heat exchanger (22), an oil filter (24) and / or an oil tank (15) are formed or mounted on the module housing (33), and the pump unit, the heat exchanger, the oil filter and / or the oil tank are components of a hydraulic circuit for cooling / lubricating an electric motor (EM) and a transmission (7).

11. The power equipment according to claim 1, characterized in that: The metal casting is a die casting.

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