Synchronous bearings and electric axle drive systems for vehicles

Abstract

The present invention provides a synchronous bearing and an electric shaft drive system for a vehicle. The synchronous bearing (B) comprises an inner ring (B1), an outer ring (B2), a rolling element (B3) and a retaining frame (B4). The outer circumference of the inner ring (B1) is recessed radially inward to define a plurality of grooves (G). The rolling element (B3) is accommodated in the grooves (G). The grooves (G) have deep parts (G1) and shallow parts (G2, G3) with different radial depths at different positions in the circumference of the synchronous bearing (B). When the retaining frame (B4) is subjected to an axial driving force and moves, the retaining frame (B4) can abut against the inner ring (B1) and then move in the axial and circumferential directions at the same time, so that the rolling element (B3) moves between the deep part (G1) and the shallow part (G2, G3), so that the rolling element (B3) can roll freely or be locked by the inner ring (B1) and the outer ring (B2). The synchronous bearing according to the present invention has a simple structure and is easy to operate, and can smoothly carry out the torque transmission or cutting process of the input shaft and the output shaft.

Description

Technical Field

[0001] The present invention relates to the field of motor vehicles, in particular to the field of vehicle transmissions, specifically to the eAxle drive system in a pure electric vehicle or a hybrid vehicle, and more specifically to a synchronizing bearing for synchronizing an input shaft and an output shaft in the eAxle drive system and the eAxle drive system of the vehicle. Background Art

[0002] In the prior art, a synchronizer is usually used to improve the shifting performance of a transmission of a motor vehicle. The synchronizer can bring an input shaft and a shifting gear to the same rotational speed (i.e., speed synchronization) and couple them in a rotation-resistant manner after such synchronization.

[0003] For electric vehicles, including pure electric vehicles and hybrid (gasoline-electric hybrid) vehicles, their electric drive modes include central motor drive and in-wheel motor drive. A common layout form of the central motor drive system is also called the eAxle drive system.

[0004] Figure 1 and Figure 2 shows an application of a synchronizer S in the eAxle drive system. The synchronizer S is used to achieve synchronous rotation of the input shaft 1 and the shifting gear 2. The synchronizer S includes a synchronizing ring S1, a gear hub S2, a gear sleeve S3, a shift fork S4, and a synchronizer slider S5. The gear hub S2 is connected to the input shaft 1, for example, by splines in a torsion-resistant (non-rotatable relative to each other) manner. The gear sleeve S3 engages the gear hub S2 from the radially outer side and can be axially slid by the action of the shift fork S4. A plurality of ( Figure 2 in this case, three) synchronizer sliders S5 are equally spaced in the grooves on the circumferential surface of the gear hub S2. The synchronizer slider S5 includes a plurality of sub-components such as a spring and steel balls. The shifting gear 2 is sleeved on the outer periphery of the input shaft 1 and is rotatably connected to the input shaft 1. The clutch gear ring 3 is torsion-resistantly connected to the shifting gear 2. During the shifting process, the shift fork S4 drives the gear sleeve S3 to move axially. The gear sleeve S3 drives the synchronizer slider S5 to slide axially, so that the synchronizer slider S5 abuts against the synchronizing ring S1. The synchronizing ring S1 rotates a certain angle relative to the gear sleeve S3 and locks the teeth of the gear sleeve S3 and the synchronizing ring S1. The synchronizing ring S1 and the clutch gear ring 3 form a friction pair. The frictional force gradually reduces the speed difference between the synchronizing ring S1 and the clutch gear ring 3. Finally, the gear sleeve S3 and the clutch gear ring 3 achieve tooth engagement, completing the entire synchronization process. By changing the position of the shift fork S4, the synchronizer S can selectively bring the shifting gear 2 into synchronous rotation with the input shaft 1 or prevent the shifting gear 2 from rotating with the input shaft 1.

[0005] However, the above solution has the following disadvantages:

[0006] (i) The synchronizer S includes a large number of sub-components, has a complex structure, and is costly.

[0007] (ii) The external shapes of the components of the synchronizer S are complex. For example, the shape parameters of the teeth of the clutch gear ring 3 and the gear sleeve S3 are relatively complex.

[0008] (iii) The components of the synchronizer S have high requirements for installation accuracy during the installation process. For example, the spline fit and the fit of the tapered surface ring involved all put forward high requirements for the positioning accuracy.

[0009] (iv) The shifting distance (mainly referring to the axial distance) is long, resulting in a long shifting time.

[0010] (v) The force required for shifting is large, and friction is relied on to achieve synchronization during the shifting process.

[0011] (vi) Among the sub-components included in the synchronizer S, there are components that are prone to damage. For example, the sub-components such as the spring and the steel ball included in the slider S5 are all prone to damage, and the reliability is low. Summary of the Invention

[0012] The object of the present invention is to overcome or at least mitigate the deficiencies existing in the above-mentioned prior art, and to provide an alternative solution for the synchronizer.

[0013] According to a first aspect of the present invention, there is provided a synchronizing bearing, which includes an inner ring, an outer ring, rolling elements and a cage. The inner ring is used for non-rotatably connecting with a first component, the outer ring is used for non-rotatably connecting with a second component, the outer peripheral surface of the inner ring is recessed radially inwards to define a plurality of grooves, and the rolling elements are received in the grooves. Among them,

[0014] The grooves have deep parts and shallow parts with different radial depths at different positions in the circumferential direction of the synchronizing bearing. The shallow parts are located at the circumferential ends of the grooves. The radial distance from the bottom of the deep part of the groove to the outer ring is greater than the diameter of the rolling element, and the radial distance from the bottom of the shallow part of the groove to the outer ring is less than the diameter of the rolling element.

[0015] The sides of the inner ring facing the cage in the grooves along the circumferential direction are respectively an inner ring first surface and an inner ring second surface. The surface of the cage facing the inner ring first surface is a cage first surface, and the surface of the cage facing the inner ring second surface is a cage second surface.

[0016] At least one of the inner ring first surface and the cage first surface is a surface that is inclined in the circumferential direction while extending axially. At least one of the inner ring second surface and the cage second surface is a surface that is inclined in the circumferential direction while extending axially.

[0017] Thus, during the movement of the cage under the axial driving force, the cage can abut against the inner ring and then move both axially and circumferentially, causing the rolling elements to move between the deep part and the shallow part, so that the rolling elements can roll freely or be locked by the inner ring and the outer ring.

[0018] In at least one embodiment, the first surface of the inner ring and the first surface of the cage are parallel to each other, and / or

[0019] the second surface of the inner ring and the second surface of the cage are parallel to each other.

[0020] In at least one embodiment, the shallow part includes a first shallow part and a second shallow part, and the deep part is circumferentially located between the first shallow part and the second shallow part.

[0021] In at least one embodiment, the bottom surface of the groove is V-shaped in the circumferential direction.

[0022] In at least one embodiment, when the rolling element is located in the deep part, the cage does not contact the inner ring.

[0023] In at least one embodiment, the synchronous bearing further includes a fork, and the fork can provide the axial driving force to the cage,

[0024] the cage extends axially to the outer region of the inner ring and the outer ring and further bends radially outward to be connected to the fork.

[0025] In at least one embodiment, the material of the rolling element includes steel.

[0026] According to the second aspect of the present invention, there is provided an electric axle drive system for a vehicle, which includes a motor, an input shaft, a first shift gear, an output shaft, a second shift gear, the first shift gear and the second shift gear are meshed, the input shaft is connected to the rotor of the motor, and the electric axle drive system further includes a synchronous bearing according to the present invention,

[0027] the first shift gear is sleeved on the outer circumference of the input shaft and can rotate relative to the input shaft, the second shift gear is fixedly connected to the output shaft, the input shaft is connected to the inner ring of the synchronous bearing as the first component, and the first shift gear is connected to the outer ring of the synchronous bearing as the second component, or

[0028] The first shift gear is fixedly connected to the input shaft, the second shift gear is sleeved on the outer periphery of the output shaft rotatably relative to the output shaft, the output shaft is connected to the inner ring of the synchronizing bearing as the first component, and the second shift gear is connected to the outer ring of the synchronizing bearing as the second component.

[0029] When the rolling elements are located in the shallow part, the torque of the input shaft is transmitted to the output shaft through the synchronizing bearing. When the rolling elements are located in the deep part, the torque transmission between the input shaft and the output shaft is cut off.

[0030] According to a third aspect of the present invention, there is provided an electric axle drive system for a vehicle, which includes a motor, an input shaft, a first shift gear, an output shaft, a second shift gear. The first shift gear and the second shift gear are meshed, the input shaft is connected to the rotor of the motor, and the electric axle drive system further includes a synchronizing bearing according to the present invention.

[0031] The first shift gear is sleeved on the outer periphery of the input shaft rotatably relative to the input shaft, the second shift gear is fixedly connected to the output shaft, the input shaft is connected to the inner ring of the synchronizing bearing as the first component, and the first shift gear is connected to the outer ring of the synchronizing bearing as the second component, or

[0032] The first shift gear is fixedly connected to the input shaft, the second shift gear is sleeved on the outer periphery of the output shaft rotatably relative to the output shaft, the output shaft is connected to the inner ring of the synchronizing bearing as the first component, and the second shift gear is connected to the outer ring of the synchronizing bearing as the second component.

[0033] When the rolling elements are located in the first shallow part, the motor rotates forward and the electric axle drive system drives the vehicle forward.

[0034] When the rolling elements are located in the second shallow part, the motor rotates reversely and the electric axle drive system drives the vehicle backward.

[0035] In at least one embodiment, the inner ring and the first component are splined, and the inner ring cannot move axially relative to the first component.

[0036] The outer ring and the second component are splined or welded, and the outer ring cannot move axially relative to the second component.

[0037] The synchronizing bearing according to the present invention has a simple structure and convenient operation, and can enable the torque transmission or cut-off process between the input shaft and the output shaft to proceed smoothly. Description of the Drawings

[0038] Figure 1 It is a schematic diagram of a synchronizer for an electric axle drive system in the prior art (the circled part is the corresponding enlarged part).

[0039] Figure 2 is Figure 1 a sectional view taken along the line a-a of

[0040] Figure 3 It is a schematic diagram of an electric axle drive system according to an embodiment of the present invention (the circled part is the corresponding enlarged part).

[0041] Figure 4 is Figure 3 a sectional view taken along the line a1-a1 of

[0042] Figure 5 is Figure 4 a sectional view taken along the line b-b of

[0043] Explanation of reference numerals

[0044] 1, 10 Input shafts;

[0045] 2 Shifting gears; 21 First shifting gear; 22 Second shifting gear;

[0046] 3 Clutch gear ring; 30 Output shaft; 40 Differential;

[0047] S Synchronizer; S1 Synchronizing ring; S2 Gear hub; S3 Gear sleeve; S4 Fork; S5 Synchronizer slider;

[0048] B Synchronous bearing; B1 Inner ring; B2 Outer ring; B3 Roller; B4 Cage; B5 Fork;

[0049] G Groove; G1 Deep part; G2 First shallow part; G3 Second shallow part;

[0050] F11 First face of the inner ring; F12 Second face of the inner ring; F21 First face of the cage; F22 Second face of the cage;

[0051] C1 First circumferential direction; C2 Second circumferential direction; D1 First axial direction; D2 Second axial direction. Detailed implementation manners

[0052] The following describes exemplary embodiments of the present invention with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not used to exhaust all possible ways of the present invention, nor to limit the scope of the present invention.

[0053] The present invention uses a bearing assembly (hereinafter referred to as a synchronous bearing) to replace the synchronizer in the transmission of the prior art, so that the shifting process of the transmission is carried out smoothly. The following refers to Figures 3 to 5Introduce the synchronous bearing and the electric axle drive system according to the present invention.

[0054] Unless otherwise specified below, refer to Figure 3 , A represents the axial direction of the synchronous bearing, and this axial direction A is consistent with the axial direction of the input shaft 10; R represents the radial direction of the synchronous bearing, and this radial direction R is consistent with the radial direction of the input shaft 10; the circumferential direction referred to in the present invention is consistent with the circumferential direction of the synchronous bearing.

[0055] The electric axle drive system according to the present invention includes an input shaft 10, a first shift gear 21, a synchronous bearing B, an output shaft 30, a second shift gear 22, and a differential 40. A motor (not shown in the figure) is connected to the input end of the input shaft 1. The first shift gear 21 is sleeved on the outer periphery of the input shaft 10 so as to be rotatable relative to the input shaft 10, the second shift gear 22 is fixedly connected to the output shaft 30, and the first shift gear 21 and the second shift gear 22 are meshed with each other. The synchronous bearing B can selectively transmit torque or cut off torque transmission between the input shaft 10 and the first shift gear 21, so that the torque is selectively transmitted or not transmitted to the output shaft 30. The output shaft 30 is further connected to the differential 40.

[0056] The synchronous bearing B includes an inner ring B1, an outer ring B2, rolling elements B3, a cage B4, and a fork B5. The outer ring B2 is torsionally connected (non-rotatable relative to each other) to the first shift gear 21, and the inner ring B1 is torsionally connected to the input shaft 10. For example, the outer ring B2 and the first shift gear 21 are connected together by laser welding or the two are connected by splines, and the inner ring B1 and the input shaft 10 are connected by splines. Preferably, neither the inner ring B1 nor the outer ring B2 can axially move relative to the input shaft 10. A plurality (four in this embodiment) of rolling elements B3 are equidistantly arranged in a groove G on the outer peripheral surface of the inner ring B1. Preferably, the rolling elements B3 are made of steel.

[0057] Refer to Figure 4 , the bottom surface of the groove G facing the radial outside is uneven. Looking at the cross-section of the groove G perpendicular to the axial direction A along the axial direction A, the bottom surface of the groove G in this embodiment is V-shaped. The groove depth in the middle region of the groove G in the circumferential direction is larger, which is the deep part G1; the groove depths in the regions at both ends of the groove G in the circumferential direction are smaller, which are the first shallow part G2 and the second shallow part G3 respectively. The radial distance from the bottom of the deep part G1 to the outer ring B2 is greater than the diameter of the rolling element B3, and the radial distances from the bottoms of the first shallow part G2 and the second shallow part G3 to the outer ring B2 are both smaller than the diameter of the rolling element B3.

[0058] The cage B4 connects all the rolling elements B3 together. The cage B4 extends axially to the outer regions of the inner ring B1 and the outer ring B2 and further bends radially outward. The cage B4 is connected to the fork B5 at its radially outer part. The fork B5 is located radially outside the outer ring B2.

[0059] The fork B5 is used to give the cage B4 an axial driving force, so that the cage B4 moves axially. Due to the special structure of the cage B4 and the inner ring B1, the cage B4 will contact the inner ring B1 during the axial movement and move circumferentially under the guidance of the inner ring B1, thereby driving the rolling element B3 to move circumferentially. The following is combined with Figure 4 and Figure 5 Introduces the special structure of cage B4 and inner ring B1 and the movement of cage B4.

[0060] In each groove G, the inner ring B1 forms two opposite circumferentially oriented side surfaces, namely the inner ring first surface F11 and the inner ring second surface F12; the retainer B4 has two circumferentially oriented surfaces opposite to the side surfaces of the inner ring B1 in the portion located in the groove G, namely the retainer first surface F21 and the retainer second surface F22. The inner ring first surface F11 and the retainer first surface F21 are arranged face to face, and the inner ring second surface F12 and the retainer second surface F22 are arranged face to face.

[0061] In this embodiment, the first surface F11 of the inner ring, the second surface F12 of the inner ring, the first surface F21 of the retainer, and the second surface F22 of the retainer are all inclined planes. When viewed from the radial inside to the radial outside, these four planes extend from one axial end to the other axial end and are inclined counterclockwise in the circumferential direction at the same time. In this embodiment, the above four planes are parallel.

[0062] Next, we will introduce the different movement positions of the rolling element B3 driven by the cage B4 in the groove G and the corresponding working conditions of the synchronous bearing B.

[0063] (1) Rolling element B3 is located in the deep part G1

[0064] Figure 5 This corresponds to the state where the rolling element B3 is located in the deep portion G1 of the groove G. This position corresponds to the non-engaged state of the synchronous bearing B.

[0065] In this state, the rolling element B3 does not contact the outer ring B2, and no torque is transmitted between the inner ring B1 and the outer ring B2. At this time, the input shaft 10 of the electric shaft drive system cannot transmit torque to the output shaft 30, and the vehicle is in a parking or neutral state.

[0066] Preferably, at this time, there is a gap between the first surface F11 of the inner ring and the first surface F21 of the retainer, and there is a gap between the second surface F12 of the inner ring and the second surface F22 of the retainer, so that at this time, the retainer B4 will not rub against the inner ring B1.

[0067] (2) Rolling element B3 is located in the first shallow part G2

[0068] When the retainer B4 is moved by the fork B5, along Figure 5Moving along the first axial direction D1 indicated by the solid arrow, the second surface F22 of the cage will abut against the second surface F12 of the inner ring. After that, the cage B4 is guided by the second surface F12 of the inner ring and moves along the first axial direction D1 and the first circumferential direction C1 (refer to the solid curve arrow in Figure 4 ). During this movement, the distance between the bottom surface of the groove G contacted by the rolling element B3 and the outer ring B2 becomes smaller and smaller and finally becomes smaller than the diameter of the rolling element B3. Thus, the rolling element B3 is finally locked by the inner ring B1 and the outer ring B2. At this time, the synchronous bearing B is in the engaged state.

[0069] In this state, the rolling element B3 is pressed by the inner ring B1 and the outer ring B2, and the inner ring B1, the outer ring B2 and the rolling element B3 are in a relatively stationary state. The torque of the inner ring B1 is transmitted to the outer ring B2 through the rolling element B3, and the torque of the input shaft 10 of the electric shaft drive system can be transmitted to the output shaft 30 through the synchronous bearing B. At this time, for example, if the motor rotates forward, the vehicle is in the forward state.

[0070] (3) The rolling element B3 is located in the second shallow part G3

[0071] When the cage B4 is toggled by the fork B5 and moves along the second axial direction D2 indicated by the dashed arrow in Figure 5 , the first surface F21 of the cage will abut against the first surface F11 of the inner ring. After that, the cage B4 is guided by the first surface F11 of the inner ring and moves along the second axial direction D2 and the second circumferential direction C2 (refer to the dashed arrow in Figure 4 ). During this movement, the distance between the bottom surface of the groove G contacted by the rolling element B3 and the outer ring B2 becomes smaller and smaller and finally becomes smaller than the diameter of the rolling element B3. Thus, the rolling element B3 is finally locked by the inner ring B1 and the outer ring B2. At this time, the synchronous bearing B is in the engaged state.

[0072] Similar to the state where the rolling element B3 is located in the first shallow part G2, in this state, the rolling element B3 is pressed by the inner ring B1 and the outer ring B2, and the inner ring B1, the outer ring B2 and the rolling element B3 are in a relatively stationary state. The torque of the inner ring B1 is transmitted to the outer ring B2 through the rolling element B3, and the torque of the input shaft 10 of the electric shaft drive system can be transmitted to the output shaft 30 through the synchronous bearing B. At this time, for example, if the motor rotates in reverse, the vehicle is in the reverse state.

[0073] It should be understood that in order to provide the engaged state of the synchronizing bearing B, the groove G may also have only one shallow part. In the present embodiment, the synchronizing bearing B provides only two states: engaged and disengaged. When the synchronizing bearing B is in the engaged state, the rolling elements B3 are located in the shallow part of the groove G (the first shallow part G2 or the second shallow part G3); when the synchronizing bearing B is in the disengaged state, the rolling elements B3 are located in the deep part G1 of the groove G. In order to provide the two states of engaged and disengaged, the synchronizing bearing B may have only one shallow part and one deep part, wherein the radial distance R from the deep part to the outer ring B2 is greater than the diameter of the rolling element B3, and the radial distance R from the shallow part to the outer ring B2 is less than the diameter of the rolling element B3. For example, in other embodiments, the bottom surface of the groove G may be an inclined plane such that one end of the groove G in the circumferential direction is a shallow part and the other end is a deep part.

[0074] It should be understood that the bottom surface of the groove G may not be a plane either. For example, in other embodiments, the bottom surface of the groove G may be a curved surface having a deep part and a shallow part.

[0075] It should be understood that the four surfaces of the inner ring first surface F11, the inner ring second surface F12, the cage first surface F21, and the cage second surface F22 do not have to be parallel to each other, and these four surfaces do not have to be planes. Since the inner ring first surface F11 and the cage first surface F21 will abut against each other during the movement of the cage B4, and the inner ring second surface F12 and the cage second surface F22 will abut against each other during the movement of the cage B4, it is only necessary to satisfy that at least one of the inner ring first surface F11 and the cage first surface F21 is inclined, and at least one of the inner ring second surface F12 and the cage second surface F22 is inclined, and the above-mentioned inclined surfaces are inclined along the circumferential direction while extending from one axial end to the other end. Preferably, the inner ring first surface F11 and the cage first surface F21 are parallel to each other. Preferably, the inner ring second surface F12 and the cage second surface F22 are parallel to each other.

[0076] It should be understood that the synchronizing bearing B in the present invention realizes the engagement of the synchronizing bearing B by relying on the frictional force between the rolling elements B3 and the inner ring B1 and the outer ring B2. When the synchronizing bearing B needs to transmit a large torque, the number of rolling elements B3 can be increased.

[0077] It should be understood that the synchronizing bearing B according to the present invention can also be installed on the output shaft 30. At this time, the inner ring of the synchronizing bearing B is torsionally connected to the output shaft 30, and the outer ring is torsionally connected to the second shift gear 22 installed on the output shaft 30. The first shift gear 21 is fixedly connected to the input shaft 10, and the second shift gear 22 is sleeved on the outer periphery of the output shaft 30 so as to be rotatable relative to the output shaft 30. In this text, the component (such as the input shaft 10 or the output shaft 30) connected to the inner ring B1 is also referred to as the first component, and the component (such as the first shift gear 21 or the second shift gear 22) connected to the outer ring B2 is also referred to as the second component.

[0078] The present invention has at least one of the following advantages:

[0079] (i) In the present invention, the synchronizing bearing B is used to replace the synchronizer S in the prior art. The synchronizing bearing B has a simple structure and a small number of components.

[0080] (ii) The geometric shape of the synchronizing bearing is simple, and there is no need to machine complex tooth profiles, saving the cost of components.

[0081] (iii) Since the number of components of the synchronizing bearing B is small, the mating relationship between components is simple, and the dimension chain is simple.

[0082] (iv) The assembly method of the synchronizing bearing B is simpler than that of the synchronizer S, and there is no need for a pressing process or installing a snap ring, etc.

[0083] (v) The synchronizing bearing B occupies a small space, and the required installation space is also small. It can be installed on the input shaft 10 according to needs, or can be installed on the output shaft 30.

[0084] (vi) The axial movement of the fork B5 of the synchronizing bearing B is used to generate the circumferential movement of the cage B4. The conversion from the axial movement to the circumferential movement is achieved by the inclined surface located on the inner ring B1 and / or the cage B4. The greater the inclination degree of the inclined surface, the greater the circumferential movement range of the cage B4 brought about by the axial movement of the fork B5. By adjusting the inclination degree of the inclined surface, the axial movement range of the fork B5 can be made smaller. The control method of the synchronizing bearing B is simple, and the force (shifting force) required for the synchronizing bearing B to change the working position is also smaller.

[0085] (v) The torque transmission capacity of the synchronizing bearing B can be increased by increasing the number of rolling elements B3.

[0086] (vi) The components of the synchronizing bearing B are not easily damaged, and even during the disassembly and maintenance process, the reliability of each component is relatively high.

[0087] Of course, the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications to the above embodiments of the present invention under the teaching of the present invention without departing from the scope of the present invention. For example, the synchronous bearing according to the present invention is not limited to being used in electric vehicles, and it can also be used in other occasions where it is necessary to selectively transmit torque or cut off torque.

Claims

1. A synchronous bearing (B), comprising an inner ring (B1), an outer ring (B2), a rolling element (B3) and a retaining frame (B4), wherein the inner ring (B1) is used to be connected to a first component in a non-rotatable manner, and the outer ring (B2) is used to be connected to a second component in a non-rotatable manner, and the outer circumference of the inner ring (B1) is recessed radially inward to define a plurality of grooves (G), and the rolling element (B3) is received in the grooves (G), wherein: The groove (G) has a deep portion (G1) and a shallow portion (G2, G3) with different radial depths at different positions in the circumferential direction of the synchronous bearing (B); the shallow portion (G2, G3) is located at the end of the groove (G) in the circumferential direction; the radial distance from the groove bottom of the deep portion (G1) to the outer ring (B2) is greater than the diameter of the rolling element (B3); the radial distance from the groove bottom of the shallow portion (G2, G3) to the outer ring (B2) is less than the diameter of the rolling element (B3); The side surfaces of the inner ring (B1) facing the retainer (B4) along the circumferential direction in the groove (G) are respectively the inner ring first surface (F11) and the inner ring second surface (F12); the surface of the retainer (B4) facing the inner ring first surface (F11) is the retainer first surface (F21); and the surface of the retainer (B4) facing the inner ring second surface (F12) is the retainer second surface (F22). At least one of the inner ring first surface (F11) and the retainer first surface (F21) is a surface extending in the axial direction and tilted in the circumferential direction, and at least one of the inner ring second surface (F12) and the retainer second surface (F22) is a surface extending in the axial direction and tilted in the circumferential direction, Therefore, when the retaining frame (B4) is moved by the axial driving force, the retaining frame (B4) can abut against the inner ring (B1) and move axially and circumferentially at the same time, so that the rolling body (B3) moves between the deep part (G1) and the shallow part (G2, G3), so that the rolling body (B3) can roll freely or be locked by the inner ring (B1) and the outer ring (B2).

2. The synchronous bearing (B) according to claim 1, characterized in that: The inner ring first surface (F11) and the cage first surface (F21) are parallel to each other, and / or The inner ring second surface (F12) and the retainer second surface (F22) are parallel to each other.

3. The synchronous bearing (B) according to claim 1, characterized in that: The shallow portion (G2, G3) includes a first shallow portion (G2) and a second shallow portion (G3), and the deep portion (G1) is located between the first shallow portion (G2) and the second shallow portion (G3) in the circumferential direction.

4. The synchronous bearing (B) according to claim 3, characterized in that: The bottom surface of the groove (G) is V-shaped in the circumferential direction.

5. The synchronous bearing (B) according to claim 1, characterized in that: When the rolling element (B3) is located in the deep portion (G1), the retaining frame (B4) does not contact the inner ring (B1).

6. The synchronous bearing (B) according to claim 1, characterized in that: The synchronous bearing (B) further comprises a shift fork (B5), wherein the shift fork (B5) is capable of providing the axial driving force to the retaining frame (B4). The retainer (B4) extends axially to the outer regions of the inner ring (B1) and the outer ring (B2), and is further bent radially outward to be connected to the shift fork (B5).

7. The synchronous bearing (B) according to claim 1, characterized in that: The rolling element (B3) is made of steel.

8. An electric axle drive system for a vehicle, comprising a motor, an input shaft (10), a first shift gear (21), an output shaft (30), and a second shift gear (22), wherein the first shift gear (21) and the second shift gear (22) are meshed, and the input shaft (10) is connected to a rotor of the motor, characterized in that: The electric shaft drive system further comprises a synchronous bearing (B) according to any one of claims 1 to 7, The first shift gear (21) is rotatably sleeved on the outer circumference of the input shaft (10) relative to the input shaft (10), the second shift gear (22) is fixedly connected to the output shaft (30), the input shaft (10) is connected to the inner ring (B1) of the synchronous bearing (B) as the first component, and the first shift gear (21) is connected to the outer ring (B2) of the synchronous bearing (B) as the second component, or The first shift gear (21) is fixedly connected to the input shaft (10), the second shift gear (22) is rotatably sleeved on the outer circumference of the output shaft (30) relative to the output shaft (30), the output shaft (30) is connected to the inner ring (B1) of the synchronous bearing (B) as the first component, and the second shift gear (22) is connected to the outer ring (B2) of the synchronous bearing (B) as the second component, When the rolling element (B3) is located in the shallow part (G2, G3), the torque of the input shaft (10) is transmitted to the output shaft (30) through the synchronous bearing (B), and when the rolling element (B3) is located in the deep part (G1), the torque transmission between the input shaft (10) and the output shaft (30) is cut off.

9. An electric axle drive system for a vehicle, comprising a motor, an input shaft (10), a first shift gear (21), an output shaft (30), and a second shift gear (22), wherein the first shift gear (21) and the second shift gear (22) are meshed, and the input shaft (10) is connected to a rotor of the motor, characterized in that: The electric shaft drive system further comprises a synchronous bearing (B) according to claim 3 or 4, The first shift gear (21) is rotatably sleeved on the outer circumference of the input shaft (10) relative to the input shaft (10), the second shift gear (22) is fixedly connected to the output shaft (30), the input shaft (10) is connected to the inner ring (B1) of the synchronous bearing (B) as the first component, and the first shift gear (21) is connected to the outer ring (B2) of the synchronous bearing (B) as the second component, or The first shift gear (21) is fixedly connected to the input shaft (10), the second shift gear (22) is rotatably sleeved on the outer circumference of the output shaft (30) relative to the output shaft (30), the output shaft (30) is connected to the inner ring (B1) of the synchronous bearing (B) as the first component, and the second shift gear (22) is connected to the outer ring (B2) of the synchronous bearing (B) as the second component, When the rolling body (B3) is located at the first shallow portion (G2), the motor rotates forward, and the electric shaft drive system drives the vehicle forward. When the rolling body (B3) is located in the second shallow portion (G3), the motor rotates in the reverse direction, and the electric axle drive system drives the vehicle to move backward.

10. The electric axle drive system for a vehicle according to claim 8 or 9, characterized in that: The inner ring (B1) is spline-connected to the first component, and the inner ring (B1) cannot move axially relative to the first component. The outer ring (B2) and the second component are spline-connected or welded, and the outer ring (B2) cannot move axially relative to the second component.

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