Power equipment for axles

Abstract

The invention relates to a power device for an electrified axle of a two-track vehicle, the electrified axle having a power unit (1) in which an electric motor (EM) is driven to wheels (9) via a transmission, wherein the electric motor (EM) is arranged transversely in the axle, wherein a stator housing (23) of the electric motor (EM) extends axially in the vehicle transverse direction (y) together with a transmission housing (25), wherein the power unit (1) is supported in the vehicle body in a three-point bearing arrangement via three unit bearings (53, 54, 55). According to the invention, the three-point bearing arrangement has two unit bearings (53, 54) on the transmission side, via which the transmission housing (25) is supported in the vehicle body.

Description

Technical Field

[0001] The invention relates to a power device for an electrified axle of a dual-track vehicle. Background Art

[0002] An electrified axle for a two-track motor vehicle has an electric motor which is driven via a transmission to a flange shaft which in turn extends to the wheels.

[0003] The electric motor and the transmission are components of a power unit, which is supported on the subframe of the vehicle body, for example, by a three-point or four-point support structure. The transmission has a transmission stage, via which the electric motor is connected to the input side of the axle differential. On its output side, the flange shaft extends in the direction of the corresponding wheel.

[0004] In a power unit of the type described, the motor is arranged parallel to the flange shaft axis. The stator housing of the motor extends axially in the transverse direction of the vehicle together with the transmission housing, in which the transmission stage and the axle differential are arranged. A power unit of this type is supported in the vehicle body in a three-point support structure via three unit supports. During vehicle operation, reaction forces are introduced from the wheels via the flange shaft into the axle differential and then into the power unit. In order to ensure operationally reliable torque support for the reaction forces, the three-point support structure must be designed accordingly to be structurally rigid, space-intensive and material-costly. Due to the high installation density in the chassis, this can lead to installation space problems.

[0005] DE 10 2012 012 327 A1 discloses an arrangement of a motor unit in a power unit compartment of a motor vehicle. DE 100 21 044 B4 discloses a vehicle equipped with a fuel cell system. EP 1 674 316 B1 discloses a fastening structure for a power motor. DE 699 14973 T2 discloses a system for an electric power unit. Summary of the invention

[0006] The object of the present invention is therefore to provide a drive unit for an electrified axle of a two-track vehicle, in which a three-point support of the drive unit allows reduced component costs, reduced installation space requirements and reduced material costs compared to the prior art.

[0007] The invention is based on a power unit for an electrified axle of a two-track vehicle. The power unit comprises a power unit, in which an electric motor is connected to the input side of an axle differential via a transmission stage. The axle differential is respectively transmitted from both sides in the transverse direction of the vehicle to a flange shaft extending to the wheels. In the installed state, the electric motor is installed transversely in the axle, that is, parallel to the flange shaft axis. The stator housing of the electric motor extends axially in the transverse direction of the vehicle together with a transmission housing, in which the transmission stage and the axle differential are arranged. The power unit is supported in the vehicle body via exactly three unit bearings in a three-point bearing structure. During the operation of the vehicle, reaction forces are introduced from the wheels via the flange shaft into the axle differential and from there further into the power unit. The invention relates to a torque support of these reaction forces, which can achieve reduced component costs, reduced installation space requirements and reduced material costs compared to the prior art. For this purpose, the three-point bearing structure comprises two unit bearings on the transmission side, by which the transmission housing is supported in the vehicle body. The two transmission-side unit bearings are arranged on opposite sides in the longitudinal direction of the vehicle with the flange shaft axis as a reference, thereby providing moment support in the two flange shaft rotation directions.

[0008] In one technical embodiment, the transmission mechanism housing can be composed of two housing parts in total, and the two housing parts are arranged in sequence along the axial direction of the vehicle. The two housing parts are an intermediate housing flanged on the stator housing and a housing cover that closes the internal space of the transmission mechanism housing. The housing cover and the intermediate housing have support walls respectively. The support walls of the housing cover and the intermediate housing are axially opposite to each other along the lateral direction of the vehicle. In addition, the support walls have support positions for the transmission mechanism shaft and the flange shaft respectively. For the stable rotation support of the transmission mechanism shaft and the flange shaft, the housing cover and the intermediate housing are correspondingly designed to be structurally rigid. In order to achieve reliable support for the operation of the power unit, it is preferred that the first unit support part of the transmission mechanism side of the unit support parts on the two transmission mechanism sides is formed on the housing cover, and the second unit support part on the transmission mechanism side is formed on the intermediate housing. The housing cover and the intermediate housing can be correspondingly designed as metal castings, and the unit support parts on the transmission mechanism side are respectively made of the same material and formed in one piece on the metal casting.

[0009] For good rotational support of the transmission shaft and the flange shaft, the bearing walls of the housing cover and the intermediate housing are designed with appropriate material costs and structural rigidity. In a preferred embodiment, the first unit bearing on the transmission side can be located in the bearing wall plane of the housing cover, while the second unit bearing on the transmission side can be located in the bearing wall plane of the intermediate housing. In this way, the bearing walls of the housing cover and the intermediate housing also act as a shear field in a dual-functional manner, which can introduce reaction forces into the shear bearing part in a non-deformable manner during vehicle operation, thereby achieving structurally rigid moment support.

[0010] Since the two unit supports are constructed directly on the transmission housing, the lateral offset (lever arm length) relative to the axle differential when viewed in the transverse direction of the vehicle is relatively small, so that, for example, deflection or twisting of the power unit due to applied reaction forces can be easily prevented in terms of design.

[0011] As described above, the transmission-side unit bearing according to the invention is a component of a three-point bearing. Unlike the two transmission-side unit bearings, the third unit bearing is formed directly on the stator housing in order to support the component weight here in an operationally reliable manner.

[0012] In a structurally simple embodiment variant, each unit bearing can be designed as a rubber metal sleeve bearing structure, which is pressed into a fastening hole of the transmission housing and / or the stator housing. The fastening holes can be formed in one piece on the transmission housing or on the stator housing with the same material. In order to achieve particularly effective torque support, it is preferred that the bearing axes of the unit bearings on the two transmission sides are parallel to the flange shaft axis, and in particular the bearing axes of the unit bearings on the stator housing side are also parallel to the flange shaft axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0014] Figure 1 A schematic diagram showing an electrified axle;

[0015] Figure 2 The power unit is shown separately;

[0016] Figure 3 A detailed view showing the stator housing, the intermediate housing and the housing cover of the power unit;

[0017] Figure 4 A schematic alternative diagram of a power plant is shown. DETAILED DESCRIPTION

[0018] Figure 1An electrified axle is shown, the power unit 1 of which has an electric machine EM and a transmission. The electric machine EM is connected via a spur gear stage 2 and via the axle differential 4 of the transmission to the right and left flange shafts 5, 7, which extend to the wheels 9 of the axle. The rotor shaft 11 of the electric machine EM is coaxially connected to the transmission input shaft 12 via the torque coupling 6 shown. The rotor 49 is placed on the rotor shaft 11 in a rotationally fixed manner, which cooperates with the stator 51 arranged in a rotationally fixed manner on the stator housing 23.

[0019] On the transmission input shaft 12 is a fixed gear 13, which is part of the spur gear stage 2. The fixed gear 13 of the transmission input shaft 12 meshes with a fixed gear 17 which is disposed on the intermediate shaft 15. On the intermediate shaft 15 is arranged a further fixed gear 19 which in turn meshes with an input-side external gear 21 of the axle differential. Figure 1 In the embodiment, the motor EM is installed transversely, that is, parallel to the axes of the two flange shafts 5 and 7.

[0020] like Figure 2 and 3 As shown, the electric machine EM has a cylindrical stator housing 23, which extends axially in the vehicle transverse direction y together with a transmission housing 25. The spur gear stage 2 and the axle differential 4 are arranged in the transmission housing 25. Figure 2 and Figure 3 In the embodiment, the transmission housing 25 is constructed in two parts, that is, it has an intermediate housing 27 and a housing cover 29. Figure 3 As shown, the intermediate housing 27 is flange-connected to the front side of the stator housing 23 at the first bolt position S1. The housing cover 29 is flange-connected to the intermediate housing 27 via the second bolt position S2. The housing cover 29 closes the transmission mechanism internal space 30 ( Figure 3 ).exist Figure 3 In the embodiment, the transmission internal space 30 is axially delimited in the vehicle transverse direction y by the bearing wall 31 of the intermediate housing 27 and the bearing wall 33 of the housing cover 29. The bearing wall 31 of the intermediate housing 27 has a bearing opening 35, in which the rotor shaft 11 of the electric motor EM is rotatably supported. In addition, the bearing wall 31 of the intermediate housing 27 has a shaft channel 39, in which the left flange shaft 5 is rotatably supported. In addition, the bearing wall 31 of the intermediate housing 27 is designed with a rotatable bearing position 41 for the intermediate shaft 15. The bearing wall 33 of the housing cover 29 has two bearing openings 43, 45 for the transmission input shaft 12 and the intermediate shaft 15, as well as a shaft channel 47, in which the right flange shaft 7 is rotatably supported.

[0021] Figure 4The installation position of the power unit 1 is shown. Therefore, the power unit 1 is supported on the schematically shown subframe 57 using a total of three unit supports 53, 54, 55 in a three-point support structure. Figure 4 In the embodiment, the subframe 57 has two lateral subframe longitudinal beams 59 , which are connected to a subframe cross beam 61 at the front and rear of the vehicle, respectively.

[0022] The core of the present invention is the design of a three-point bearing structure. It has two transmission-side unit bearings 53, 54, through which the transmission housing 25 is supported on the subframe 57. The two transmission-side unit bearings 53, 54 are oriented with the flange shaft axis F ( Figure 2 ) is arranged on opposite sides along the longitudinal direction x of the vehicle, that is, at the front and rear of the vehicle. Figure 4 In the embodiment, the first unit support 53 on the transmission side is connected to the rear subframe cross member 61, and the second unit support 54 on the transmission side is connected to the front subframe cross member 61. On the other hand, the third unit support 55 is arranged on the stator housing 23 that mainly supports the electric motor EM, and the center of gravity SP of the power unit 1 is located in the area of ​​the stator housing 23.

[0023] During vehicle operation, the reaction force F R The flange shafts 5, 7 are introduced from the wheels 9 into the axle differential 4 and from there into the rest of the drive unit 1. R To provide stable moment support, the unit supports 53, 54 on the two transmission sides are positioned with very small lateral offsets Δy1, Δy2 relative to the axle differential 4, as viewed in the vehicle transverse direction y. Figure 4 ).

[0024] like Figure 3 As shown, the unit bearings 53, 54, 55 are each implemented as rubber metal sleeve bearings. Therefore, each of the unit bearings 53, 54 shown has a sleeve-shaped inner bearing core 63, which is connected to the outer sleeve 67 via an elastomer 65. The radially inner bearing core 63 can be connected to the bearing bracket of the subframe 57 via a bearing pin (not shown). Figure 2 and Figure 3 The bearing axes L of the two transmission-side unit bearings 53 , 54 and the stator housing-side unit bearing 55 are each oriented in the vehicle transverse direction y.

[0025] Figure 3 or Figure 4It is shown that the first unit bearing 53 on the transmission side is formed on the housing cover 29. The first unit bearing 53 on the transmission side is located in a common plane together with the bearing wall 33 of the housing cover 29. Therefore, under load, the bearing wall 33 acts as a structurally rigid shear bearing part. The second unit bearing 54 on the transmission side is formed in the same way on the intermediate housing 27. The second unit bearing 54 on the transmission side is located in a common plane together with the bearing wall 33 of the intermediate housing 27, so that the bearing wall 33 of the intermediate housing 27 also acts as a structurally rigid shear bearing part under load.

[0026] List of reference numerals:

[0027] 1 Power Unit

[0028] 2 Transmission mechanism

[0029] 3 cylindrical gear stages

[0030] 4 Axle Differential

[0031] 5.7 Flange shaft

[0032] 9. Wheels

[0033] 11 Rotor shaft

[0034] 12 Transmission input shaft

[0035] 13 Fixed gear

[0036] 15 Intermediate shaft

[0037] 17 Fixed Gear

[0038] 23 Stator housing

[0039] 25 Transmission housing

[0040] 27 Intermediate housing

[0041] 29 Housing cover

[0042] 30 Transmission mechanism internal space

[0043] 31 Support wall of intermediate housing 27

[0044] 33 Support wall of transmission mechanism cover 29

[0045] 35 Support opening

[0046] 39 axis channel

[0047] 41 Rotation bearing position

[0048] 43, 45 support opening

[0049] 47 axis channel

[0050] 49 Rotor shaft

[0051] 51 stator

[0052] 53, 54, 55 unit support

[0053] 57 Subframe

[0054] 59 Subframe longitudinal beam

[0055] 61 Subframe cross member

[0056] 63 inner support core

[0057] 65 Elastomer

[0058] 67 Jacket

[0059] S1, S2 bolt position

[0060] L Support axis

[0061] F Flange shaft axis

[0062] Δy1, Δy2 lateral offset

[0063] F R Reaction force

Claims

1. A power device for an electrified axle of a two-track vehicle, the power device comprising a power unit (1), in which an electric motor (EM) is transmitted to wheels (9) via a transmission mechanism, wherein: The electric motor (EM) is arranged transversely in the vehicle axle, wherein the stator housing (23) of the electric motor (EM) extends axially along the vehicle transverse direction (y) together with the transmission housing (25), wherein the power unit (1) is supported in the vehicle body via three unit supports (53, 54, 55) in a three-point support structure in order to provide a reaction force (F R ) provides moment support, the three-point support structure has two unit support parts (53, 54) on the transmission mechanism side, the transmission mechanism housing (25) is supported in the vehicle body by the two unit support parts on the transmission mechanism side, the transmission mechanism housing (25) is composed of two housing parts, and the two housing parts are arranged axially in sequence along the transverse direction (y) of the vehicle, the transmission mechanism housing is specifically composed of an intermediate housing (27) flange-connected to the stator housing (23) and a housing cover (29) that closes the internal space (30) of the transmission mechanism housing, the housing cover (29) and the intermediate housing (27) respectively have support walls (31, 33), and the support walls are axially opposed to each other, the transmission mechanism shaft (11, 12, 15) and the flange shaft (5, 7) are rotatably supported in the supporting walls (31, 33) of the housing cover (29) and the intermediate housing (27), the first unit supporting part (53) on the transmission side is constructed on the housing cover (29), and the second unit supporting part (54) on the transmission side is constructed on the intermediate housing (27), characterized in that each unit supporting part (53, 54) is designed as a rubber metal sleeve supporting structure, which is pressed into the fastening hole (69) of the transmission housing (25), the first unit supporting part (53) on the transmission side is located in the supporting wall plane of the housing cover (29), and / or the second unit supporting part (54) on the transmission side is located in the supporting wall plane of the intermediate housing (27).

2. The power equipment according to claim 1, characterized in that: The electric motor (EM) is connected to the input side of the axle differential (4) via a transmission stage (2), the axle differential transmits power from both sides along the vehicle transverse direction (y) to the flange shafts (5, 7) extending to the wheels (9), and / or the electric motor (EM) is parallel to the axis of the flange shafts (5, 7), and / or the transmission stage (2) and the axle differential (4) are arranged in a transmission housing (25), and / or during vehicle operation, the flange shafts (5, 7) cause a reaction force (F R ) is introduced into the power unit (1) via the axle differential (4).

3. The power equipment according to claim 1 or 2, characterized in that: Due to the configuration on the transmission housing (25), each transmission-side unit support (53, 54) can be positioned with as small a lateral offset (Δy1, Δy2) relative to the axle differential (4) as possible, viewed in the vehicle transverse direction (y).

4. The power equipment according to claim 1 or 2, characterized in that: The third unit support portion (55) is formed on the stator case (23).

5. The power equipment according to claim 1 or 2, characterized in that: The support axes (L) of the unit support parts (53, 54) on the two transmission mechanism sides and the flange shaft axis (F) are parallel to each other.

6. The power device according to claim 5, characterized in that: The support axis of the unit support part (55) on the stator housing side and the flange shaft axis (F) are parallel to each other.

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