Differential, electric drive system and vehicle

Abstract

The differential gear, the electric drive system and the vehicle are provided, and relate to the technical field of vehicles.The differential gear comprises a housing, a gear ring and a transmission assembly.The housing comprises a shell and a first protrusion arranged on the shell.The shell has a containing cavity.The gear ring comprises a ring body and a second protrusion arranged on the inner side of the ring body.The ring body is sleeved on the shell.The first protrusion on the side away from the shell is in interference fit with the inner side of the ring body.The second protrusion on the side away from the ring body is in interference fit with the outer side of the shell.The transmission assembly is arranged in the containing cavity and is used for driving the rotation of a half shaft.The NVH performance of the electric drive system can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, and more specifically, to a differential, an electric drive system, and a vehicle. Background Technology

[0002] The differential is a core component of a vehicle's transmission system. Its core function is to allow the half-shafts to rotate at different speeds when the vehicle is turning or driving on uneven surfaces, thereby preventing the tires from slipping on the ground and ensuring the smoothness and stability of the vehicle's ride.

[0003] However, existing electric drive systems have low NVH performance.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] This disclosure provides a differential, an electric drive system, and a vehicle that can improve NVH performance.

[0006] According to a first aspect of this disclosure, a differential is provided, comprising: The outer casing includes a housing and a first protrusion disposed on the housing, the housing having a receiving cavity; A gear ring includes a ring body and a second protrusion disposed on the inner side of the ring body. The ring body is fitted onto the housing. The side of the first protrusion away from the housing is interference-fitted with the inner side of the ring body, and the side of the second protrusion away from the ring body is interference-fitted with the outer side of the housing. A transmission assembly is disposed in the receiving cavity and is used to drive the half shaft to rotate.

[0007] In one embodiment of this disclosure, the first protrusion and the second protrusion abut against each other along the axial direction of the ring body, and the first protrusion and the second protrusion are fixedly connected by a connector.

[0008] In one embodiment of this disclosure, the sum of the heights of the first protrusion and the second protrusion along the axial direction of the ring body is not greater than the height of the ring body.

[0009] In one embodiment of this disclosure, the position where the first protrusion is in interference fit with the inner side of the ring body is the first fitting position, and the position where the second protrusion is in interference fit with the outer side of the shell body is the second fitting position. The first fitting position and the second fitting position are distributed along the axial direction of the ring body.

[0010] In one embodiment of this disclosure, the first protrusion extends circumferentially along the housing, and the second protrusion extends circumferentially along the ring body.

[0011] In one embodiment of this disclosure, the ring body has a first inner ring wall and a second inner ring wall. The first inner ring wall, the second inner ring wall, and the second protrusion are distributed along the axial direction of the ring body. The distance between the first inner ring wall and the axis of the ring body is greater than the distance between the second inner ring wall and the axis of the ring body. The side of the first protrusion away from the shell is interference-fitted with the second inner ring wall.

[0012] In one embodiment of this disclosure, the ring body further has a transition slope, through which the first inner ring wall and the second inner ring wall are connected.

[0013] In one embodiment of this disclosure, the transmission assembly includes a support shaft, a planetary gear, and a half-shaft gear; The axis of the support shaft is perpendicular to the axis of the housing. The planetary gear is rotatably connected to the support shaft on the same axis. The half-shaft can extend into the receiving cavity and is fixedly connected to the half-shaft gear on the same axis. The planetary gear meshes with the half-shaft gear.

[0014] In one embodiment of this disclosure, the support shaft is fixedly connected to the housing by a positioning member, the housing has a groove, and the positioning member is disposed through the bottom of the groove and the support shaft.

[0015] In one embodiment of this disclosure, the first protrusion has a transition groove on the side away from the second protrusion, the transition groove extending radially along the ring body; The housing has a first through hole, which is connected to the receiving cavity and the transition groove, respectively. The support shaft can be fitted into the first through hole through the transition groove.

[0016] In one embodiment of this disclosure, the housing further has a second through hole and a weight-reducing groove, the second through hole communicating with the receiving cavity.

[0017] According to a second aspect of this disclosure, an electric drive system is provided, including the differential described in any of the above embodiments.

[0018] According to a third aspect of this disclosure, a vehicle is provided, including the electric drive system described in any of the above embodiments.

[0019] The differential, electric drive system, and vehicle disclosed herein, through the abutment of the first protrusion against the inner side of the gear ring and the abutment against the housing, effectively limit the radial displacement between the gear ring and the housing, increase the support stiffness of the gear ring and housing, improve the overall connection stability and torque transmission efficiency of the differential, buffer transmission impact loads, reduce rigid collisions and misalignment friction between the gear ring and the housing, reduce differential noise, and improve the service life of the differential and the NVH performance of the electric drive system. Furthermore, this differential can increase the support stiffness of the secondary gear of the reducer, thereby reducing the misalignment of the secondary gear, further reducing noise, and improving the NVH performance of the vehicle.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] Figure 1 This is a first-view structural schematic diagram of the differential in one embodiment of the present disclosure.

[0023] Figure 2 This is a structural schematic diagram of the differential from a second perspective in one embodiment of this disclosure.

[0024] Figure 3 for Figure 1 The diagram shown is an exploded schematic of the differential.

[0025] Figure 4 This is a cross-sectional schematic diagram of the differential in one embodiment of the present disclosure.

[0026] Figure 5 This is a cross-sectional schematic diagram of the differential after concealing the transmission components and bearings in one embodiment of this disclosure.

[0027] Figure 6 for Figure 1 The diagram shows the structure of the gear ring in the differential.

[0028] Figure 7 for Figure 1 The diagram shows the structure of the differential with the bearings and gear ring hidden.

[0029] Figure 8 for Figure 1The diagram shows the structure of the differential with the gear ring hidden.

[0030] Figure 9 for Figure 1 The diagram shows the structure of the transmission components in the differential.

[0031] Explanation of reference numerals in the attached figures: 1. Outer shell; 11. Housing; 111. Groove; 112. First through hole; 113. Second through hole; 114. Weight reduction groove; 12. First protrusion; 121. Transition groove; 2. Gear ring; 21. Ring body; 211. First inner ring wall; 212. Second inner ring wall; 213. Transition slope; 22. Second protrusion; 3. Transmission assembly; 31. Support shaft; 32. Planetary gear; 33. Half-shaft gear; 34. Positioning component; 4. Connecting component; 5. Bearing; 6. First mating position; 7. Second mating position. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0033] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0034] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0035] This disclosure provides a differential. See also: Figures 1-5The differential includes a housing 1, a gear ring 2, and a transmission assembly 3. The housing 1 includes a shell 11 and a first protrusion 12 located on the shell 11, and the shell 11 has a receiving cavity. The gear ring 2 includes a ring body 21 and a second protrusion 22 located on the inner side of the ring body 21. The ring body 21 is fitted onto the shell 11. The side of the first protrusion 12 away from the shell 11 is interference-fitted with the inner side of the ring body 21, and the side of the second protrusion 22 away from the ring body 21 is interference-fitted with the outer side of the shell 11. The transmission assembly 3 is located in the receiving cavity and is used to drive the half-shaft to rotate.

[0036] Thus, in the embodiments disclosed herein, the interference fit between the first protrusion 12 and the inner side of the ring 21, and the interference fit between the second protrusion 22 and the housing 11, effectively restricts the radial displacement between the gear ring 2 and the housing 11, increases the support stiffness of the gear ring 2 and the housing 11, improves the overall connection stability and torque transmission efficiency of the differential, buffers transmission impact loads, reduces rigid collisions and misalignment friction between the gear ring 2 and the housing 11, reduces differential noise, and improves the service life of the differential and the NVH performance of the electric drive system. Furthermore, this differential can increase the support stiffness of the secondary gear of the reducer, thereby reducing the misalignment of the secondary gear, further reducing noise, and improving the NVH performance of the vehicle.

[0037] It should be noted that the outer circumference of the ring body 21 has a toothed portion, and the secondary gear of the reducer can mesh with the toothed portion of the ring body 21.

[0038] In one embodiment of this disclosure, the housing 11 can be a body of revolution, such as a sphere, cylinder, or quasi-sphere. The receiving cavity can be spherical, ellipsoidal, or similar shapes to facilitate the protection of the transmission assembly 3.

[0039] In one embodiment of this disclosure, see Figure 1 , Figure 3 , Figure 4 The differential also includes two bearings 5, which are located at both ends of the housing 11 along its own axis. One end of the housing 11 is rotatably connected to and fitted with a bearing 5 to facilitate the rotatable connection between the differential and the protective housing of the electric drive system.

[0040] In one embodiment of this disclosure, see Figure 3 , Figure 6 , Figure 7The first protrusion 12 extends circumferentially along the housing 11, and the second protrusion 22 extends circumferentially along the ring body 21. In other words, the first protrusion 12 is an annular protrusion coaxially arranged with the housing 11, and the second protrusion 22 is an annular protrusion coaxially arranged with the ring body 21. The first protrusion 12 is integrally connected to the housing 11, and the second protrusion 22 is integrally connected to the ring body 21. Thus, by setting the first protrusion 12 and the second protrusion 22 as annular protrusions, the support stiffness of the gear ring 2 and the housing 11 is further increased, which helps to reduce differential noise and improve the vehicle's NVH performance and comfort.

[0041] In one embodiment of this disclosure, the first protrusion 12 may include a plurality of first protrusions spaced apart circumferentially along the housing 11, with the side of each first protrusion away from the housing 11 abutting against the inner side of the ring 21. The second protrusion 22 may include a plurality of second protrusions spaced apart circumferentially along the ring 21, with the side of each second protrusion away from the ring 21 abutting against the housing 11. Thus, by using a plurality of first and second protrusions to increase the supporting stiffness between the housing 11 and the ring 21, compared to the annular first protrusion 12 and second protrusion 22, this approach helps to reduce costs while maintaining supporting stiffness.

[0042] In one embodiment of this disclosure, see Figure 3 , Figure 4 , Figure 5 The first protrusion 12 and the second protrusion 22 abut against each other along the axial direction of the ring body 21. The first protrusion 12 and the second protrusion 22 are fixedly connected by the connector 4. In this way, the first protrusion 12 and the second protrusion 22 are fixedly connected by the connector 4, which further improves the connection performance and support rigidity of the housing 11 and the ring body 21, thereby improving the reliability and safety of the differential.

[0043] As one example, there can be multiple connectors 4, evenly distributed circumferentially along the first protrusion 12. Connectors 4 can be connecting bolts, which can pass through the first protrusion 12 and the second protrusion 22, and can be threaded onto either the first protrusion 12 or the second protrusion 22. As another example, connector 4 can be connecting pins, which can pass through the first protrusion 12 and the second protrusion 22 and be engaged with them. As yet another example, the first protrusion 12 and the second protrusion 22 can be fixedly connected by welding, bonding, snap-fitting, or other methods.

[0044] In one embodiment of this disclosure, see Figure 4 and Figure 5Along the axial direction of the ring body 21, the sum of the heights of the first protrusion 12 and the second protrusion 22 is not greater than the height of the ring body 21. For example, along the axial direction of the ring body 21, the sum of the heights of the first protrusion 12 and the second protrusion 22 can be less than or equal to the height of the ring body 21. This helps to reduce materials and lower costs.

[0045] In one embodiment of this disclosure, see Figure 4 and Figure 5 The first protrusion 12 is positioned at the inner side of the ring body 21 where it is interference-fitted, and the second protrusion 22 is positioned at the outer side of the shell 11 where it is interference-fitted, which is the second fit position 7. The first fit position 6 and the second fit position 7 are distributed along the axial direction of the ring body 21 so as to realize two interference fits between the shell 1 and the gear ring 2, which is beneficial to improving the support rigidity of the gear ring 2 and the shell 1.

[0046] In one embodiment of this disclosure, see Figure 4 , Figure 5 The ring body 21 has a first inner ring wall 211 and a second inner ring wall 212, which are the inner circumferential walls of the ring body 21. The first inner ring wall 211, the second inner ring wall 212, and the second protrusion 22 are distributed along the axial direction of the ring body 21. The distance between the first inner ring wall 211 and the axis of the ring body 21 is greater than the distance between the second inner ring wall 212 and the axis of the ring body 21. The side of the first protrusion 12 away from the housing 11 is press-fitted with the second inner ring wall 212. Thus, during the assembly process of the first protrusion 12 and the ring body 21, the first inner ring wall 211 may not contact the first protrusion 12 or may contact it and be movable, so as to provide a preliminary guiding effect on the first protrusion 12, which facilitates the press-fitting of the first protrusion 12 with the second inner ring wall 212 and improves the assembly efficiency.

[0047] In one embodiment of this disclosure, see Figure 4 , Figure 5 The ring body 21 also has a transition slope 213, through which the first inner ring wall 211 and the second inner ring wall 212 are connected. Along the direction from the first inner ring wall 211 to the second inner ring wall 212, the distance between the transition slope 213 and the axis of the ring body 21 decreases sequentially. Thus, through the gradual change in distance between the transition slope 213 and the axis of the ring body 21, during the assembly process of the first protrusion 12 and the ring body 21, the transition slope 213 can precisely guide the first protrusion 12 to the second inner wall, facilitating the assembly of the first protrusion 12 and the ring body 21, preventing the first protrusion 12 from jamming, and improving the assembly efficiency of the differential.

[0048] In one embodiment of this disclosure, the edges of the first protrusion 12 and the second protrusion 22 are chamfered to improve the smoothness of the assembly process.

[0049] In one embodiment of this disclosure, see Figure 3 , Figure 4 , Figure 9 The transmission assembly 3 includes a support shaft 31, a planetary gear 32, and a half-shaft gear 33 located in the receiving cavity. The axis of the support shaft 31 is perpendicular to the axis of the housing 11. The planetary gear 32 is coaxially rotatably connected to the support shaft 31. The half-shaft gear can extend into the receiving cavity and is coaxially fixedly connected to the half-shaft gear 33. The planetary gear 32 meshes with the half-shaft gear 33. Specifically, there are two planetary gears 32 and two half-shaft gears 33. The two planetary gears 32 are coaxial and opposite to each other, and the two half-shaft gears 33 are coaxial and opposite to each other. One planetary gear 32 can mesh with both half-shaft gears 33. In this way, the support shaft 31 can provide limiting support for the planetary gear 32, allowing a single planetary gear 32 to mesh with two half-shaft gears 33 simultaneously. This not only enables power to be transmitted evenly within the differential, improving the balance and stability of torque distribution and ensuring smooth differential rotation of the two half-shafts under conditions such as turning, but also disperses the force during meshing through the symmetrical gear structure design, reducing the load on a single set of gears, reducing gear meshing wear and transmission noise. At the same time, it simplifies the power transmission path within the differential, eliminating the need for additional power distribution components, further improving the overall compactness and operational reliability of the transmission assembly 3, and further enhancing the vehicle's NVH performance.

[0050] In one embodiment of this disclosure, see Figure 3 , Figure 4 , Figure 7 The support shaft 31 and the housing 11 are fixedly connected by a positioning member 34. The housing 11 has a groove 111, and the positioning member 34 is disposed through the bottom of the groove 111 and the support shaft 31. The positioning member 34 can extend radially along the support shaft 31 and may include structures such as positioning pins and positioning bolts. The size of the groove 111 is larger than the size of the hole that mates with the positioning member 34. In this way, the support shaft 31 and the housing 11 can be fixedly connected by the positioning member 34 to limit the movement of the planetary gear 32 and improve the stability during transmission. In addition, the groove 111 facilitates the operator to quickly position the positioning member 34, improving positioning efficiency and reliability.

[0051] In one embodiment of this disclosure, see Figure 2 , Figure 4 , Figure 7The first protrusion 12 has a transition groove 121 on the side away from the second protrusion 22, and the transition groove 121 extends radially along the ring body 21. The housing 11 has a first through hole 112, which communicates with the receiving cavity and the transition groove 121 respectively. The support shaft 31 can be fitted into the first through hole 112 through the transition groove 121. Specifically, there are two transition grooves 121, which are collinearly arranged. There are also two first through holes 112, which are collinearly arranged, and both ends of the support shaft 31 fit into the two first through holes 112. In this way, during the assembly process of the support shaft 31, the transition groove 121 can provide initial guidance and avoidance for the support shaft 31, improving the assembly efficiency of the support shaft 31.

[0052] In one embodiment of this disclosure, see Figure 7 , Figure 8 The housing 11 also has a second through hole 113 and multiple weight-reducing grooves 114. The second through hole 113 communicates with the receiving cavity. The shape of the second through hole 113 can be circular, elliptical, polygonal, or an irregular geometric shape. The second through hole 113 exposes at least the transmission component 3, and there are two second through holes 113. The line connecting the two second through holes 113 passes through the axis of the housing 11. In this way, exposing the transmission component 3 through the second through hole 113 allows lubricating oil to flow into the receiving cavity through the second through hole 113 to lubricate the transmission component 3, which helps to improve the service life of the transmission component 3. At the same time, the transmission component 3 can also be installed in the receiving cavity through the second through hole 113, which facilitates the rapid assembly of the differential and improves assembly efficiency. In addition, the multiple weight-reducing holes can reduce the weight of the housing 11 and reduce costs.

[0053] This disclosure also provides an electric drive system, including a protective housing, a motor, a reducer, and a differential as described in any of the above embodiments. The motor, reducer, and differential are housed within the protective housing. The output shaft of the motor is connected to the input shaft of the reducer. The secondary gear of the reducer meshes with the ring gear 2 of the differential. The housing 11 of the differential is rotatably connected to the protective housing via bearings 5. The power output from the motor is reduced and amplified by the reducer before being transmitted to the ring gear 2. The ring gear 2 drives the housing 1 to rotate. The housing 1 drives the planetary gear 32 to revolve via a support shaft 31. The planetary gear 32 meshes with the half-shaft gear 33, driving the half-shaft to rotate, which in turn drives the wheels to rotate, thus enabling the vehicle to move. This electric drive system possesses all the beneficial effects of the aforementioned differential, which will not be elaborated upon here.

[0054] This disclosure also provides a vehicle, which can be a pure electric vehicle or a hybrid vehicle. The vehicle may include a body, chassis, half-shafts, wheels, and an electric drive system as described in any of the above embodiments. The electric drive system is mounted on the chassis, and the half-shafts are coaxially and fixedly connected to the half-shaft gear 33 of the differential. The wheels are connected to the half-shafts to provide driving power to the vehicle. During driving, when turning or driving on uneven roads, the differential can achieve differential rotation of the left and right wheels, avoiding tire slippage and ensuring the smoothness and stability of vehicle driving. This vehicle has all the beneficial effects of the above-described electric drive system, which will not be elaborated further here.

[0055] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A differential, characterized in that, include: The outer casing (1) includes a housing (11) and a first protrusion (12) provided on the housing (11), the housing (11) having a receiving cavity; The toothed ring (2) includes a ring body (21) and a second protrusion (22) disposed on the inner side of the ring body (21). The ring body (21) is fitted onto the housing (11). The side of the first protrusion (12) away from the housing (11) is interference-fitted with the inner side of the ring body (21), and the side of the second protrusion (22) away from the ring body (21) is interference-fitted with the outer side of the housing (11). The transmission assembly (3) is located in the receiving cavity and is used to drive the half shaft to rotate.

2. The differential according to claim 1, characterized in that, The first protrusion (12) and the second protrusion (22) abut against each other along the axial direction of the ring body (21), and the first protrusion (12) and the second protrusion (22) are fixedly connected by a connector (4).

3. The differential according to claim 2, characterized in that, Along the axial direction of the ring body (21), the sum of the heights of the first protrusion (12) and the second protrusion (22) is not greater than the height of the ring body (21).

4. The differential according to claim 3, characterized in that, The first protrusion (12) is in the position of interference fit with the inner side of the ring body (21) as the first fitting position (6), and the second protrusion (22) is in the position of interference fit with the outer side of the shell (11) as the second fitting position (7). The first fitting position (6) and the second fitting position (7) are distributed along the axial direction of the ring body (21).

5. The differential according to claim 1, characterized in that, The first protrusion (12) extends circumferentially along the housing (11), and the second protrusion (22) extends circumferentially along the ring (21).

6. The differential according to claim 1, characterized in that, The ring body (21) has a first inner ring wall (211) and a second inner ring wall (212). The first inner ring wall (211), the second inner ring wall (212), and the second protrusion (22) are distributed along the axial direction of the ring body (21). The distance between the first inner ring wall (211) and the axis of the ring body (21) is greater than the distance between the second inner ring wall (212) and the axis of the ring body (21). The side of the first protrusion (12) away from the shell (11) is press-fitted with the second inner ring wall (212).

7. The differential according to claim 6, characterized in that, The ring body (21) also has a transition slope (213), through which the first inner ring wall (211) and the second inner ring wall (212) are connected.

8. The differential according to claim 1, characterized in that, The transmission assembly (3) includes a support shaft (31), a planetary gear (32), and a half-shaft gear (33). The axis of the support shaft (31) is perpendicular to the axis of the housing (11), the planetary gear (32) is rotatably connected to the support shaft (31) on the same axis, the half shaft can extend into the receiving cavity and is fixedly connected to the half shaft gear (33) on the same axis, and the planetary gear (32) meshes with the half shaft gear (33).

9. The differential according to claim 8, characterized in that, The support shaft (31) is fixedly connected to the housing (11) by a positioning member (34). The housing (11) has a groove (111), and the positioning member (34) is disposed through the bottom of the groove (111) and the support shaft (31).

10. The differential according to claim 8, characterized in that, The first protrusion (12) has a transition groove (121) on the side away from the second protrusion (22), the transition groove (121) extending radially along the ring body (21); The housing (11) has a first through hole (112), which is connected to the receiving cavity and the transition groove (121) respectively. The support shaft (31) can be fitted into the first through hole (112) through the transition groove (121).

11. The differential according to any one of claims 1 to 10, characterized in that, The housing (11) also has a second through hole (113) and a weight reduction groove (114), the second through hole (113) being in communication with the receiving cavity.

12. An electric drive system, characterized in that, Includes the differential as described in any one of claims 1 to 11.

13. A vehicle, characterized in that, Includes the electric drive system as described in claim 12.

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