Electric wheel hub drive for motor vehicle

Abstract

The invention relates to an electric wheel hub drive (1) for a motor vehicle, comprising: a wheel carrier (2); an electric machine (3) having a stator (4) and a rotor (5) arranged so as to be rotatable about a main axis of rotation (A); the electric wheel hub driving device further comprises a stator support (6) which is connected with the wheel carrier (2) in a torsion-proof manner; a rotor carrier (7) which is connected to the rotor (5) in a rotationally fixed manner and which is mounted in a rotatable manner relative to the wheel carrier (2), the stator carrier (6) having a disc-shaped part (8) and a cylindrical part (9) which is arranged radially outside of the disc-shaped part (8), the disc-shaped portion (8) has a first passage (10) for a shaft (11) of an actuator (12) of a disconnect clutch (13), wherein a first clutch half (13.1) and a second clutch half (13.2) of the disconnect clutch (13) are arranged radially inside the cylindrical portion (9).

Description

Field of the Invention

[0001] The present invention relates to an electric wheel hub drive device for a motor vehicle as described in the preamble of claim 1. Background Art

[0002] For an electric wheel hub drive device for a motor vehicle, a disconnect clutch (Disconnect device) can be used. For example, an actuating motor is used to operate the disconnect clutch.

[0003] Electric wheel hub drive devices are known, for example, from DE 10 2019 133 283 A1 and US2019 / 0 023 128A1.

[0004] US2020 / 0 287 495A1 describes a control device for an electric motor having a first set of coil windings arranged to form a first sub - motor and a second set of coil windings arranged to form a second sub - motor, wherein the current in the first set of coil windings is controlled using a first pulse - width modulation (PWM) having a first switching sequence, the current in the second set of coil windings is controlled using a second pulse - width modulation (PWM) having a second switching sequence, wherein the control device includes means arranged to measure the current in each coil winding of the first set of coil windings, and wherein, when it is determined that the sum of the currents in the first set of coil windings is substantially non - zero, the first PWM value is derived from the voltage value for generating the second PWM. Summary of the Invention

[0005] The object of the present invention is to provide a novel electric wheel hub drive device for a motor vehicle.

[0006] According to the present invention, this object is achieved by an electric wheel hub drive device for a motor vehicle having the features of claim 1.

[0007] Advantageous embodiments of the present invention are the subject matter of the dependent claims.

[0008] Within the scope of this application, "anti - torsional" is used as follows: If two elements are arranged coaxially with respect to each other (with respect to their axis of rotation or with respect to an axis of rotational symmetry) and they are connected to each other such that they always rotate with the same angular velocity, then these two elements are connected to each other in an anti - torsional manner. If an element cannot rotate relative to the housing, then this element is connected to the housing in an anti - torsional manner.

[0009] Within the scope of this application, "radially overlapping" is used as follows: If two elements (especially substantially rotationally symmetric elements) are at least each partly arranged within a region of the same radial coordinate (especially the same angular coordinate), then these two elements are arranged to radially overlap with respect to a common axis.

[0010] Within the scope of the present application, "axially overlapping" is used in the following manner: If two elements are each at least partially arranged within the region of the same axial coordinate, then these two elements are arranged to be axially overlapping with respect to a common axis.

[0011] Within the scope of the present application, "radially internal" is used in the following manner: If a first element is arranged within a region of a smaller radius compared to a second element, then this first element is arranged to be radially internal to the second element with respect to a common axis.

[0012] According to the present invention, an electric wheel hub drive device for a motor vehicle is provided. The electric wheel hub drive device has a wheel carrier; the electric wheel hub drive device has an electric motor, which has a stator and a rotor arranged to be rotatable about a main rotational axis; the electric wheel hub drive device has a stator support, which is torsionally rigidly connected to the wheel carrier; the electric wheel hub drive device has a rotor support, which is torsionally rigidly connected to the rotor and is rotatably supported relative to the wheel carrier, wherein the stator support has a disc-shaped part and a cylindrical part, and the cylindrical part is arranged radially externally to the disc-shaped part. According to the present invention, the disc-shaped part has a first passage for the shaft of an actuator for disengaging a clutch. The disengaging clutch also has a first clutch half and a second clutch half, and according to the present invention, the first clutch half and the second clutch half are arranged radially internally to the cylindrical part.

[0013] The disengaging clutch is designed to torsionally rigidly couple the rotor to the wheel rim or to decouple the rotor from the wheel rim. The first clutch half and the second clutch half are designed here to establish a connection in a form-fitting or friction-fitting manner. In the coupled state of the disengaging clutch, the first clutch half and the second clutch half are connected to each other in a form-fitting or friction-fitting manner. In the decoupled state, the first clutch half and the second clutch half are not connected to each other. The first clutch half and the second clutch half can be designed as, for example, the clutch halves of a claw clutch or the clutch halves of a multi-plate clutch.

[0014] In one embodiment, the disc-shaped part has a second passage for a bolt connection, wherein the bolt connection is designed to torsionally rigidly connect the disc-shaped part to the wheel carrier.

[0015] In one embodiment, the second passage is arranged within a region of a substantially smaller radius compared to the first passage.

[0016] In one embodiment, the cylindrical part has a channel designed to accommodate a coolant.

[0017] In one embodiment, the rotor bearing is arranged radially inside the passage and axially overlaps with the passage.

[0018] In one embodiment, the disconnect clutch further has a ring arranged radially inside the cylindrical part, wherein the ring is connected to the cylindrical part in a torsion-resistant manner and is axially displaceable relative to the cylindrical part.

[0019] In one embodiment, the cylindrical part has grooves extending parallel to the main rotation axis on its radial inner side, wherein the ring is connected to pins that engage into the grooves.

[0020] In one embodiment, the cylindrical part has a sealing surface for a seal relative to the rotor support on its radial outer side.

[0021] In one embodiment, the sealing surface is axially arranged between the stator and the brake disc.

[0022] In one embodiment, the stator support is designed as a one-piece casting.

[0023] In one embodiment, the disconnect clutch further includes a release bearing having teeth, a pinion arranged on the shaft engages into the release bearing, such that rotation of the shaft causes rotation of the release bearing by means of an actuator, whereby the ring causes the first clutch half supported in a torsion-resistant and axially displaceable manner in the rotor support to engage or disengage from the second clutch half advantageously arranged in a torsion-resistant manner on the brake disc.

[0024] The stator support used according to the invention can provide passages for coolant and electrical wires. Additionally, the stator support can provide a sealing surface for a seal relative to the rotor. Additionally, the stator support used according to the invention provides a connection for the mechanism ("Disconnect-Mechanik") of the disconnect clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of the invention are explained in more detail below with reference to the drawings.

[0026] Shown in the drawings are:

[0027] Figure 1 A schematic view showing an electric wheel drive for a motor vehicle. DETAILED DESCRIPTION

[0028] The sole drawing Figure 1Schematic view showing an electric wheel hub drive device 1 for a motor vehicle, the electric wheel hub drive device having a wheel carrier 2; having an electric motor 3 which has a stator 4 and a rotor 5 arranged so as to be rotatable about a main rotational axis A; having a stator support 6 which is torsionally rigidly connected to the wheel carrier 2; having a rotor support 7 which is torsionally rigidly connected to the rotor 5 and is rotatably supported relative to the wheel carrier 2, wherein the stator support 6 has a disc-shaped part 8 and a cylindrical part 9, and wherein the cylindrical part 9 is arranged radially outside the disc-shaped part 8. The disc-shaped part 8 has a first passage 10 for a shaft 11 of an actuator 12 for disengaging a clutch 13, wherein a first clutch half 13.1 and a second clutch half 13.2 of the disengaging clutch 13 are arranged radially inside the cylindrical part 9. Advantageously, the first clutch half 13.1 and the second clutch half 13.2 have claw-shaped teeth which engage with each other.

[0029] The rotational axis of the shaft 11 is arranged parallel to the main rotational axis.

[0030] In this embodiment, the disc-shaped part 8 has a second passage 14 for a bolt connection 15 which is designed to connect the disc-shaped part 8 to the wheel carrier 2 in a torsionally rigid manner.

[0031] Advantageously, the second passage 14 is arranged in a region of substantially smaller radius than the first passage 10.

[0032] Advantageously, the cylindrical part 9 has at least one channel 16 which is designed to accommodate a coolant. Particularly advantageously, the channel 16 has a first part arranged parallel to the main rotational axis A on the side facing the wheel carrier 2. Advantageously, the channel 16 has a second part in a region arranged axially overlapping the stator 4, the second part being arranged perpendicular to the main rotational axis A.

[0033] Advantageously, a rotor bearing 17 is provided for the rotational support of the rotor 5 and is arranged radially inside the channel 16 and axially overlapping with the channel.

[0034] Advantageously, the disengaging clutch 13 has a displacement mechanism 26 which is designed to cause the coupling and decoupling of the two clutch halves 13.1, 13.2. Advantageously, the displacement mechanism is designed to axially displace the first clutch half.

[0035] Advantageously, the displacement mechanism has a ring 18 arranged radially inside the cylindrical part 9, wherein the ring 18 is torsionally rigidly connected to the cylindrical part 9 and is axially displaceable relative to the cylindrical part 9.

[0036] The ring 18 is connected to the first clutch half 13.1, which is supported in the rotor carrier 7 in such a way that it can be axially displaced in the corresponding passage 37 and is designed to optionally engage with the second clutch half 13.2, which in turn is torsionally rigidly connected to the rim 24. Particularly advantageously, the second clutch half 13.2 is directly fixed to the brake disc carrier 23, where the brake disc carrier 23 is in turn torsionally rigidly connected to the rim 24.

[0037] Advantageously, the ring 18 is torsionally rigidly connected to the cylindrical part 9. However, the ring 18 is arranged in such a way that it can be axially displaced relative to the cylindrical part 9. In order to be torsionally rigidly connected to the ring 18, the cylindrical part 9 has a groove 19 parallel to the main rotational axis A on its radial inner side, where the ring 18 is connected to an engagement element 20, which engages with the groove 19.

[0038] A pinion 34 is also arranged at the shaft 11, which is connected to the ring 18 via a release bearing 35 with a toothing. The pinion 34 is torsionally rigidly connected to the shaft 11. The release bearing 35 has an annular shape arranged coaxially with the main rotational axis A, which has a toothing on its inner side, which is in engagement with the pinion teeth of the pinion 34. The release bearing has a ramp profile, which is designed in such a way that when the release bearing 35 undergoes a corresponding rotation by means of the ramp profile, the ring 18 can be axially displaced in the direction towards the second clutch half.

[0039] Advantageously, the ring 18 is arranged radially inside the cylindrical part 9. Particularly advantageously, the entire displacement mechanism is arranged radially inside the cylindrical part 9.

[0040] Advantageously, the cylindrical part 9 has a sealing surface on its radial outer side for a seal 21, in particular a radial seal, relative to the rotor carrier 7.

[0041] Advantageously, the sealing surface is axially arranged between the stator 4 and the brake disc 22.

[0042] The rotor bearing 17 is part of a combined bearing 28, which also includes a wheel bearing 29, where the combined bearing 28 has an outer bearing housing 30, a middle bearing housing 31 and an inner bearing housing 32, where a plurality of rolling elements 33 are arranged between the outer bearing housing 30 and the middle bearing housing 31 forming the rotor bearing 17, and a plurality of rolling elements 33 are arranged between the middle bearing housing 31 and the inner bearing housing 32 forming the wheel bearing 29.

[0043] The brake disc 22 can be designed as an Inside-Out brake disc and arranged at the brake disc carrier 23, which is torsionally rigidly connected to the rim 24. The rim 24 and the brake disc carrier 23 are torsionally rigidly connected to the inner bearing seat 32 of the wheel bearing 29 via several wheel bolts 27.

[0044] Another radial seal 25 can be arranged between the brake disc carrier 23 and the rotor carrier 7.

[0045] At the wheel carrier 2, a brake caliper 38 with brake pads 39 is also arranged. The brake caliper 38 can be designed as an inboard brake caliper 38.

[0046] The wheel carrier 2, the brake caliper 38, the brake pads 39, the stator 4, the stator carrier 6, the actuator 12, the shaft 11, the pinion 34 and the middle bearing seat 31 do not rotate with the rim 24.

[0047] The brake disc 22, the brake disc carrier 23, the inner bearing seat 32 and the second clutch half always rotate with the rim 24.

[0048] The rotor carrier 7, the rotor 5, the disconnect clutch pin 36, the ring 18, the engagement element 20 and the outer bearing seat 30 only rotate with the rim 24 when the disconnect clutch 13 is connected, i.e., when the first clutch half 13.1 is in engagement with the second clutch half.

[0049] The electric machine 3 can be designed as an axial flux machine.

[0050] To seal the rotor cavity, in particular the intermediate cavity between the rotor 5 and the stator 4, a first seal 21 can be provided, which is arranged coaxially with the rotor carrier 7 such that the first intermediate gap between the rotor carrier 7 and the stator carrier 6 is filled by the first seal 21.

[0051] The second seal 25 or more radial seals 25 can be arranged coaxially with the rotor carrier 7 such that the second intermediate gap between the rotor carrier 7 and the brake disc carrier 23 is filled by the second seal 25.

[0052] Relative to the main rotational axis A, the second seal 25 can be axially arranged on the side of the first seal 21 facing away from the wheel carrier 2.

[0053] The second seal 25 can be arranged radially inside the stator 4, i.e., in particular radially inside the region of the magnets arranged in the stator 4.

[0054] The first seal 21 can be arranged radially inside the rotor 5, i.e., in particular radially inside the region of the magnets arranged in the rotor 5.

[0055] The first connection point for connecting the brake disc carrier 23 to the inner bearing seat 32 can be arranged radially inside the second seal 25.

[0056] The brake disc 22, which is connected to the brake disc carrier 23 in a torsion-resistant manner, can be axially arranged on the side of the first seal 21 opposite the second seal 25 with respect to the main rotational axis A.

[0057] Furthermore, the third seal 40 can be arranged coaxially with the rotor carrier 7 such that the third intermediate gap between the middle bearing seat 31 (which can also be referred to as the first bearing ring) and the inner bearing seat 32 (which can also be referred to as the second bearing ring) is filled by the third seal 40.

[0058] Furthermore, there can be a second connection point for connecting the middle bearing seat 31 to the stator carrier 6 in a sealed and torsion-resistant manner. Thus, the rotor chamber is enclosed: The stator carrier 6 has a cylindrical part 9 which is sealed with respect to the first disc-shaped part 41 of the rotor carrier 7 by means of the first seal 21, and the first disc-shaped part is located on the side of the stator 4 in the axial direction. The rotor carrier 7 also has a cylindrical part 42 and a second disc-shaped part 43 connected to the cylindrical part 42, and the second disc-shaped part is sealed with respect to the brake disc carrier 23 by means of the second seal 25. The brake disc carrier 23 has a sealed connection point to the inner bearing seat 32. The inner bearing seat 32 is sealed with respect to the middle bearing seat 31 by means of the third seal 40. The middle bearing seat 31 has a sealed second connection point to the stator carrier 6.

[0059] Furthermore, a fourth seal 44 can be provided between the inner bearing seat 32 and the middle bearing seat 31 on the side of the wheel bearing 29 axially opposite the third seal 40.

[0060] The middle bearing seat 31 can be designed as a single-piece bearing seat which is both the radially outer part of the wheel bearing 29 and the radially inner part of the rotor bearing 17. Alternatively, the middle bearing seat 31 can also be designed as two bearing seats connected to each other in a torsion-resistant manner, one being the radially outer part of the wheel bearing 29 and the other being the radially inner part of the rotor bearing 17.

[0061] List of Reference Numerals

[0062] 1 Electric wheel drive

[0063] 2 Wheel carrier

[0064] 3 Electric motor

[0065] 4 Stator

[0066] 5 Rotor

[0067] 6 Stator carrier

[0068] 7 Rotor support

[0069] 8 Disc part

[0070] 9 Cylindrical part

[0071] 10 Passage

[0072] 11 Shaft

[0073] 12 Actuator

[0074] 13 Disengaging clutch

[0075] 13.1 First clutch half

[0076] 13.2 Second clutch half

[0077] 14 Passage

[0078] 15 Bolt connection

[0079] 16 Channel

[0080] 17 Rotor bearing

[0081] 18 Ring

[0082] 19 Groove

[0083] 20 Engaging element

[0084] 21 Seal, first seal

[0085] 22 Brake disc

[0086] 23 Brake disc support

[0087] 24 Rim

[0088] 25 Another radial seal, second seal

[0089] 26 Displacement mechanism

[0090] 27 Wheel bolt

[0091] 28 Combined bearing

[0092] 29 Wheel bearing

[0093] 30 Outer bearing housing

[0094] 31 Middle bearing housing

[0095] 32 Inner bearing housing

[0096] 33 Rolling element

[0097] 34 Pinion

[0098] 35 Release bearing

[0099] 37 passages

[0100] 38 brake caliper

[0101] 39 brake pad

[0102] 40 third seal

[0103] 41 first disc-shaped part

[0104] 42 cylindrical part

[0105] 43 second disc-shaped part

[0106] 44 fourth seal

[0107] A main rotation axis.

Claims

1. An electric wheel hub drive device (1) for a motor vehicle, the electric wheel hub drive device having a wheel carrier (2) which has a rim (24); the electric wheel hub drive device having an electric motor (3) which has a stator (4) and a rotor (5) arranged to be rotatable about a main rotational axis (A); the electric wheel hub drive device having a stator support (6) which is torsionally rigidly connected to the wheel carrier (2); the electric wheel hub drive device having a rotor support (7) which is torsionally rigidly connected to the rotor (5) and is rotatably supported relative to the wheel carrier (2), wherein the stator support (6) has a disc-shaped part (8) and a cylindrical part (9), and wherein the cylindrical part (9) is arranged radially outside the disc-shaped part (8). Characterized in that the disc-shaped part (8) has a first passage (10) for a shaft (11) of an actuator (12) of a disengaging clutch (13), wherein the disengaging clutch (13) is designed to torsionally rigidly connect the rotor (5) to the rim (24), and wherein a first clutch half (13.1) and a second clutch half (13.2) of the disengaging clutch (13) are arranged radially inside the cylindrical part (9).

2. The electric wheel hub drive device (1) according to claim 1, Characterized in that the disc-shaped part (8) has a second passage (14) for a bolt connection (15), wherein the bolt connection (15) is designed to torsionally rigidly connect the disc-shaped part (8) to the wheel carrier (2).

3. The electric wheel hub drive device (1) according to claim 2, Characterized in that the first clutch half (13.1) is torsionally rigidly connected to the rotor support (7), and the second clutch half (13.2) is torsionally rigidly connected to the rim (24).

4. The electric wheel hub drive device (1) according to any one of the preceding claims, Characterized in that the cylindrical part (9) has a passage (16) which is designed to accommodate a coolant.

5. The electric wheel hub drive device (1) according to claim 4, Characterized in that a rotor bearing (17) is arranged radially inside the passage (16) and axially overlaps with the passage (16).

6. The electric wheel hub drive device (1) according to any one of the preceding claims, Characterized in that the disengaging clutch (13) has a ring (18) arranged radially inside the cylindrical part (9), wherein the ring (18) is torsionally rigidly connected to the cylindrical part (9) and is axially displaceable relative to the cylindrical part (9).

7. The electric wheel hub drive device (1) according to claim 6, Characterized in that The cylindrical part (9) has a groove (19) extending parallel to the main rotation axis (A) on its radially inner side, wherein the ring (18) is connected to an engagement element (20) which engages into the groove (19).

8. The electric wheel hub drive device (1) according to any one of the preceding claims, characterized in that the cylindrical part (9) has a sealing surface for a seal (21) relative to the rotor carrier (7) on its radially outer side.

9. The electric wheel hub drive device (1) according to claim 8, characterized in that the seal (21) is arranged axially between the stator (4) and the brake disc (22).

10. The electric wheel hub drive device (1) according to any one of the preceding claims, characterized in that the stator carrier (6) is designed as a one-piece casting.

11. The electric wheel hub drive device (1) according to any one of claims 6 to 10, characterized in that the disengaging clutch (13) further comprises a release bearing (35) having teeth, and a pinion (34) arranged on the shaft (11) engages into the release bearing such that rotation of the shaft (11) causes rotation of the release bearing (35) by means of the actuator (12), whereby the ring (18) can cause the first clutch half (13.1) supported torsionally and axially displaceably in the rotor carrier (7) to engage with the second clutch half (13.2) torsionally connected to the rim (24).

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