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); a wheel bearing (29) having a first bearing ring (31) connected in a rotationally fixed manner to the wheel carrier (2) and a second bearing ring (32) arranged in a rotatable manner relative to the main axis of rotation (A); an electric machine (3) having a stator (4) and a rotor (5) arranged so as to be rotatable about the main axis of rotation (A); a stator carrier (6) which is connected to the wheel carrier (2) in a rotationally fixed manner; a rotor carrier (7) which is connected in a rotationally fixed manner to the rotor (5) and which is mounted in a rotationally fixed manner relative to the wheel carrier (2), a disconnect clutch (13) having a first clutch half (46) which is connected in a rotationally fixed manner to the rotor carrier (7) and a second clutch half (47) which is connected in a rotationally fixed manner to the second bearing ring (32), wherein a servomotor (12) of an actuator of the disconnect clutch (13) is arranged on a side of the wheel carrier (2) facing away from the first clutch half (46) and the second clutch half (47).

Description

Technical Field

[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, a servo motor is used to operate the disconnect clutch. The available space for integrating the servo motor into the wheel is small. In addition, when the servo motor is positioned in the wheel, it is difficult to access, for example, for maintenance purposes.

[0003] 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.

[0004] Furthermore, wheel hub drive devices are known from JP 2020 - 128 134A and DE 10 2022 000 035 A1, in which a disconnect clutch is also provided in each case, which has a first clutch half connected in a torsionally rigid manner to the rotor carrier and a second clutch half connected in a torsionally rigid manner to the rim, wherein the servo motor of the actuator of the disconnect clutch is directly arranged at the wheel carrier. Summary of the Invention

[0005] The object of the present invention is to provide a new 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 of the dependent claims.

[0008] Within the scope of the present application, "anti-torsion" is used in the following manner: 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 at the same angular velocity, then these two elements are connected to each other in an anti-torsion manner. If an element cannot rotate relative to the housing, then this element is connected to the housing in an anti-torsion manner.

[0009] Within the scope of the present application, "radially overlapping" is used in the following manner: If two elements (especially elements that are substantially rotationally symmetric) are arranged at least partially in the region of the same radial coordinates (and especially the same angular coordinates), then these two elements are arranged to overlap radially 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 arranged at least partially in the region of the same axial coordinates, then these two elements are arranged to overlap axially 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 in a region with a smaller radius compared to a second element, then this first element is arranged radially internal to the second element with respect to a common axis.

[0012] According to the present invention, there is provided an electric wheel hub drive device for a motor vehicle, the electric wheel hub drive device having: a wheel carrier; a wheel rim; a wheel bearing having a first bearing ring connected to the wheel carrier in an anti-torsion manner and a second bearing ring arranged to be rotatable relative to the main axis of rotation; an electric motor having a stator and a rotor arranged to be rotatable about the main axis of rotation; a stator support connected to the wheel carrier in an anti-torsion manner; having a rotor support connected to the rotor in an anti-torsion manner and supported to be rotatable relative to the wheel carrier. A disconnect clutch is provided, the disconnect clutch having a first clutch half connected to the rotor support in an anti-torsion manner and a second clutch half connected to the wheel rim in an anti-torsion manner, wherein a servo motor of the actuator of the disconnect clutch is directly arranged on the wheel carrier. Thereby, a particularly compact wheel hub drive device can be achieved, and the servo motor is easily accessible for maintenance purposes.

[0013] Particularly advantageously, the servo motor is arranged on a side of the wheel carrier facing away from the first clutch half and the second clutch half, and the servo motor is partially arranged in a recess provided in the wheel carrier for this purpose.

[0014] In a known manner, the axis of rotation of the servo motor is arranged parallel to the main axis of rotation.

[0015] Among them, the servo motor has a shaft, which is connected to the rotor of the servo motor in a torsion-resistant manner. According to the present invention, the wheel carrier has a hole, through which the shaft is guided.

[0016] Particularly advantageously, the stator support has a disc-shaped portion, which is arranged on the side of the wheel carrier facing away from the servo motor, and the disc-shaped portion has a passage through which the shaft is guided.

[0017] In one embodiment, the actuator has an axial displacement device, which is arranged on the side of the wheel carrier facing away from the servo motor and is designed to convert the rotational movement of the shaft into an axial movement parallel to the main rotational axis.

[0018] In one embodiment, the axial displacement device has a pinion, which is connected to the shaft in a torsion-resistant manner.

[0019] In one embodiment, the axial displacement device has a first bevel ring coupled to the pinion via tooth engagement and a second bevel ring connected to the stator support in a torsion-resistant manner via a groove in the stator support.

[0020] In one embodiment, a covering portion is arranged on the servo motor on the side facing away from the wheel carrier.

[0021] In one embodiment, the second bevel ring has a shift fork engaged in a sliding sleeve, such that the sliding sleeve can move axially together with the second bevel ring, but the rotation of the sliding sleeve together with the rotor support can be independent of the second bevel ring.

[0022] In one embodiment, the first bevel ring has a bevel surface, which engages with the corresponding bevel surface of the second bevel ring, such that the torsion of the first bevel ring causes the axial movement of the second bevel ring.

[0023] The disengaging clutch within the scope of the present invention includes two clutch halves (for example, as a claw clutch or a form-fitting clutch; alternatively, a multi-disc clutch or a friction clutch can also be used). The term "disengaging clutch" can also include a sliding sleeve, wherein the second clutch half of the disengaging clutch can be designed, for example, as a clearance and / or hole in the brake disc support. However, the second clutch half can also be designed as a separate claw tooth portion, which is also connected to the second bearing ring in a torsion-resistant manner.

[0024] The term "actuator of the disengaging clutch" includes all components mounted upstream of the sliding sleeve: servo motor, adjusting shaft, pinion, axial displacement device (having a pinion, a first bevel ring, a second bevel ring, and optionally balls arranged therebetween).

[0025] The protection of the actuator can be carried out by a protection device, for example, a cover, to protect it from gravel and environmental influences.

[0026] Compared with the large ring-shaped motor in the drive module, the small servo motor in the wheel carrier has advantages in terms of weight and packaging. Description of the Drawings

[0027] Embodiments of the present invention will be explained in more detail with reference to the accompanying drawings below.

[0028] As shown in the drawings:

[0029] Figure 1 A schematic view showing an electric wheel hub drive device for a motor vehicle; and

[0030] Figure 2 A schematic detailed view showing the electric wheel hub drive device. Detailed Description of the Invention

[0031] Corresponding parts in all the drawings are denoted by the same reference numerals.

[0032] Figure 1 A schematic 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 a motor 3 having a stator 4 and a rotor 5 arranged to be rotatable about a main rotational axis A; having a stator support 6 torsionally connected to the wheel carrier 2; having a rotor support 7 torsionally connected to the rotor 5 and rotatably supported relative to the wheel carrier 2, wherein the stator support 6 has a disk-shaped portion 8 and a cylindrical portion 9, wherein the cylindrical portion 9 is arranged radially outside the disk-shaped portion 8. The disk-shaped portion 8 has a first passage 10 for the shaft 11 of a servo motor 12 for disengaging a clutch 13, wherein the disengaging clutch 13 is arranged radially inside the cylindrical portion 9.

[0033] In Figure 1 In the illustrated embodiment, the disk-shaped portion 8 has a second passage 14 for a bolt connection 15 which is designed to torsionally connect the disk-shaped portion 8 to the wheel carrier 2.

[0034] In one embodiment, the second passage 14 is arranged substantially in a region of the same radius as the first passage 10.

[0035] In this embodiment, the cylindrical portion 9 has at least one channel 16 which is designed to accommodate a coolant.

[0036] In this embodiment, 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.

[0037] In this embodiment, the disengaging clutch 13 also has a second bevel ring 18 arranged radially inside the cylindrical part 9, wherein the second bevel ring 18 is torsionally connected to the cylindrical part 9 and can be axially displaced relative to the cylindrical part 9.

[0038] In this embodiment, the cylindrical part 9 has at least one groove 19 on its radial inner side, which is parallel to the main rotational axis A, wherein the bevel ring 18 is connected to a engaging element 20, which engages into the groove 19.

[0039] In one embodiment, 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.

[0040] In one embodiment, the sealing surface is axially arranged between the stator 4 and the brake disc 22.

[0041] The rotor bearing 17 is part of a combined bearing 28, which also includes a wheel bearing 29, wherein the combined bearing 28 has an outer bearing shell 30, an intermediate bearing shell 31 and an inner bearing shell 32, wherein a plurality of rolling elements 33 are arranged between the outer bearing shell 30 and the intermediate bearing shell 31 forming the rotor bearing 17, and a plurality of rolling elements 33 are arranged between the intermediate bearing shell 31 and the inner bearing shell 32 forming the wheel bearing 29.

[0042] The brake disc 22 can be designed as an Inside-Out brake disc and is arranged at a brake disc carrier 23, which is torsionally connected to the rim 24. The rim 24 and the brake disc carrier 23 are torsionally connected to the inner bearing shell 32 of the wheel bearing 29 via several wheel bolts 27.

[0043] A further radial seal 25 can be arranged between the brake disc carrier 23 and the rotor carrier 7.

[0044] The second bevel ring 18 is axially fixedly connected to a shift fork 50, which engages into a groove of the first clutch half 46.

[0045] A pinion 34 is also arranged at the shaft 11, which is in operative connection with the second bevel ring 18 via a first bevel ring 35. The first bevel ring 35 has teeth at its inner circumference, which engage with the pinion teeth of the pinion 34. The first bevel ring is arranged coaxially with the main rotational axis A. The corresponding rotation of the pinion 34 causes the first bevel ring 35 to rotate about the main rotational axis A. As a result, a first bevel, not shown in detail, of the first bevel ring 35 causes an axial displacement of the second bevel ring in the direction of the clutch halves 46, 47.

[0046] 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 internal brake caliper 38.

[0047] The wheel carrier 2, the brake caliper 38, the brake pads 39, the stator 4, the stator support 6, the servo motor 12, the shaft 11, the pinion 34 and the intermediate bearing 31 do not rotate with the rim 24.

[0048] The brake disc 22, the brake disc support 23 and the inner bearing 32 always rotate together with the rim 24.

[0049] The rotor support 7, the rotor 5, the first clutch half 46, the inclined plane ring 18, the engagement element 20 and the outer bearing 30 only rotate with the rim 24 when the disconnect clutch 13 is connected.

[0050] The electric motor 3 can be designed as an axial flux electric motor.

[0051] In order to seal the rotor chamber, 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 support 7 such that the first intermediate gap between the rotor support 7 and the stator support 6 is filled by the first seal 21.

[0052] A second seal 25 or a further radial seal 25 can be arranged coaxially with the rotor support 7 such that the second intermediate gap between the rotor support 7 and the brake disc support 23 is filled by the second seal 25.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The first connection point for connecting the brake disc support 23 to the inner bearing 32 can be arranged radially inside the second seal 25.

[0057] The brake disc 22, which is connected to the brake disc support 23 in a torsion-resistant manner, can be axially arranged relative to the main rotational axis A on the side of the first seal 21 opposite to the second seal 25.

[0058] Furthermore, the third seal 40 can be arranged coaxially with the rotor support 7 such that the third intermediate gap between the intermediate bearing shell 31 (which can also be referred to as the first bearing ring) and the inner bearing shell 32 (which can also be referred to as the second bearing ring) is filled by the third seal 40.

[0059] Furthermore, there can be a second connection point for connecting the intermediate bearing shell 31 to the stator support 6 in a sealed manner. Thereby, the rotor chamber is enclosed: The stator support 6 has a cylindrical part 9 which is sealed relative to the first disc-shaped part 41 of the rotor support 7 by means of the first seal 21, and the first disc-shaped part is located on one side of the stator 4 in the axial direction. The rotor support 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 relative to the brake disc support 23 by means of the second seal 25. The brake disc support 23 has a sealed connection point to the inner bearing shell 32. The inner bearing shell 32 is sealed relative to the intermediate bearing shell 31 by means of the third seal 40. The intermediate bearing shell 31 has a sealed second connection point to the stator support 6.

[0060] Furthermore, a fourth seal 44 can be provided between the inner bearing shell 32 and the intermediate bearing shell 31 on the side of the wheel bearing 29 which is axially opposite to the third seal 40.

[0061] The intermediate bearing shell 31 can be designed as a single-piece integral bearing shell which is both the radially outer part of the wheel bearing 29 and the radially inner part of the rotor bearing 17. Alternatively, the intermediate bearing shell 31 can also be designed as two bearing shells which are torsionally rigidly connected to each other, where one is the radially outer part of the wheel bearing 29 and the other is the radially inner part of the rotor bearing 17.

[0062] Figure 2 A schematic detailed view of the electric wheel drive 1 is shown.

[0063] The disengaging clutch 13 has a first clutch half 46 which is torsionally rigidly connected to the rotor support 7. The disengaging clutch 13 also has a second clutch half 47 which is torsionally rigidly connected to the second bearing ring 32, and the servo motor 12 of the disengaging clutch 13 is arranged directly at the wheel carrier 2. The servo motor 12 can be arranged on the side of the wheel carrier 2 which is remote from the first clutch half 46 and the second clutch half 47.

[0064] The rotational axis B of the shaft 11 is arranged parallel to the main rotational axis A.

[0065] The shaft 11 is torsionally rigidly connected to the servo motor rotor of the servo motor 12. In the Figure 1 embodiment, the wheel carrier 2 has a hole 48 through which the shaft 11 is guided.

[0066] Advantageously, the disc-shaped part 8 is arranged on the side of the wheel carrier 2 facing away from the servo motor 12, wherein the disc-shaped part 8 has a passage 10 through which the shaft 11 is guided.

[0067] The axial displacement device 26 is arranged on the side of the wheel carrier 2 facing away from the servo motor 12. The axial displacement device 26 is designed to convert the rotational movement of the shaft 11 into an axial movement parallel to the main rotational axis A.

[0068] The axial displacement device 26 includes a pinion 34 which is torsionally connected to the shaft 11. The axial displacement device 26 also includes a first bevel ring 35 and a second bevel ring 18.

[0069] The second bevel ring 18 has a shift fork 50 which engages in a groove of the first clutch half 46, so that the first clutch half can rotate with the rotor carrier 7 while the second bevel ring 18 does not rotate, wherein, however, the first clutch half 46 can be axially moved together with the second bevel ring 18.

[0070] The torsion of the shaft 11 causes the torsion of the first bevel ring 35 via the pinion 34 and the toothing, thereby causing the axial movement of the second bevel ring 18 and the first clutch half 46. The first clutch half is correspondingly coupled to the second clutch half 47 according to the rotational direction of the shaft 11, thereby coupling the rotor carrier 7 to the brake disc carrier 23 or separating the rotor carrier 7 from the brake disc carrier 23. The disengaging movement of the first clutch half 46 can be realized or supported, for example, by an axially acting spring, which is not shown here.

[0071] A covering part 49 can be arranged on the servo motor 12.

[0072] The first clutch half 46 is torsionally connected to the rotor carrier 7, because in this embodiment, the first clutch half 46 forms an engagement in the rotor carrier 7 through the passage 37. The first clutch half 46 is annular in the engagement area of the shift fork 50 and is arranged coaxially with the main rotational axis A. Advantageously, the first clutch half 46 has a claw-shaped toothing which forms an engagement through the rotor carrier 7. Advantageously, the claw-shaped toothing of the first clutch half 46 cooperates with another claw-shaped toothing which is part of the second clutch half 47.

[0073] Advantageously, the first bevel ring 35 and the second bevel ring 18 are arranged radially inside the cylindrical part 9.

[0074] The components that are arranged upstream of the disengaging clutch 13 in an operative manner, namely the servomotor 12, the shaft 11, the pinion 34, and the axial displacement device (with the pinion 34, the first bevel ring 35, the second bevel ring 18, and the balls, if appropriate, located between the bevel rings 35, 18), can be referred to together as the actuator.

[0075] List of reference numerals

[0076] 1 Electric hub drive

[0077] 2 Wheel carrier

[0078] 3 Motor

[0079] 4 Stator

[0080] 5 Rotor

[0081] 6 Stator support

[0082] 7 Rotor support

[0083] 8 Disk-shaped part

[0084] 9 Cylindrical part

[0085] 10 Passage

[0086] 11 Shaft

[0087] 12 Servomotor

[0088] 13 Disengaging clutch

[0089] 14 Passage

[0090] 15 Bolt connection

[0091] 16 Channel

[0092] 17 Rotor bearing

[0093] 18 Bevel ring

[0094] 19 Groove

[0095] 20 Engaging element

[0096] 21 Seal, first seal

[0097] 22 Brake disc

[0098] 23 Brake disc support

[0099] 24 Rim

[0100] 25 Additional radial seal, second seal

[0101] 26 Axial displacement device

[0102] 27-wheel bolt

[0103] 28-composite bearing

[0104] 29-wheel bearing

[0105] 30-outside bearing shell

[0106] 31-intermediate bearing shell, first bearing ring

[0107] 32-inside bearing shell, second bearing ring

[0108] 33-rolling element

[0109] 34-pinion

[0110] 35-inclined plane ring

[0111] 37-passageway

[0112] 38-brake caliper

[0113] 39-brake pad

[0114] 40-third seal

[0115] 41-first disc-shaped part

[0116] 42-cylindrical part

[0117] 43-second disc-shaped part

[0118] 44-fourth seal

[0119] 46-clutch half

[0120] 47-clutch half

[0121] 48-hole

[0122] 49-covering part

[0123] 50-shifting fork

[0124] A-main rotation axis

[0125] B-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); the electric wheel hub drive device having a rim (24); the electric wheel hub drive device having a wheel bearing (29), the wheel bearing having a first bearing ring (31) connected to the wheel carrier (2) in a torsion-resistant manner and a second bearing ring (32) arranged to be rotatable relative to the main rotational axis (A); the electric wheel hub drive device having a motor (3), the motor having a stator (4) and a rotor (5) arranged to be rotatable about the main rotational axis (A); the electric wheel hub drive device having a stator support (6) connected to the wheel carrier (2) in a torsion-resistant manner; the electric wheel hub drive device having a rotor support (7) connected to the rotor (5) in a torsion-resistant manner and supported to be rotatable relative to the wheel carrier (2), the electric wheel hub drive device having a disengaging clutch (13), the disengaging clutch having a first clutch half (46) connected to the rotor support (7) in a torsion-resistant manner and a second clutch half (47) connected to the rim (24) in a torsion-resistant manner, wherein a servomotor (12) of an actuator of the disengaging clutch (13) is directly arranged on the wheel carrier (2), and wherein a rotational axis (B) of a shaft (11) of the servomotor (12) is arranged parallel to the main rotational axis (A), characterized in that, the wheel carrier (2) has a hole (48), and wherein the shaft (11) is guided through the hole (48).

2. The electric wheel hub drive device (1) according to claim 1, characterized in that, the stator support (6) has a disk-shaped portion (8) arranged on a side of the wheel carrier (2) facing away from the servomotor (12), and wherein the disk-shaped portion (8) has a passage (10) through which the shaft (11) is guided.

3. The electric wheel hub drive device (1) according to claim 1 or 2, characterized in that, the actuator has an axial displacement device (26) arranged on a side of the wheel carrier (2) facing away from the servomotor (12) and designed to convert a rotational movement of the shaft (11) into an axial movement parallel to the main rotational axis (A).

4. The electric wheel hub drive device (1) according to claim 3, characterized in that, the axial displacement device has a pinion (34) connected to the shaft (11) in a torsion-resistant manner.

5. The electric wheel hub drive device (1) according to claim 4, characterized in that, the axial displacement device (26) has a first bevel ring (35) coupled to the pinion (34) via tooth engagement and a second bevel ring (18) connected to the stator support (6) in a torsion-resistant manner via a slot (19) of the stator support (6).

6. The electric hub drive device (1) according to any one of the preceding claims, characterized in that, a covering part (49), which is arranged on the servo motor (12) on the side facing away from the wheel carrier (2).

7. The electric hub drive device (1) according to claim 5, characterized in that, the second bevel ring (18) has a shift fork (50), which engages in a groove of the first clutch half (46), so that the first clutch half (46) can be axially moved together with the second bevel ring (18).

8. The electric hub drive device (1) according to claim 5, characterized in that, the first bevel ring (35) has a bevel surface, which engages with the corresponding bevel surface of the second bevel ring (18), so that the torsion of the first bevel ring (35) causes the axial movement of the second bevel ring (18).

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