A staggered differential

Abstract

This invention proposes a staggered differential, relating to the field of differential technology, comprising: a differential housing with multiple staggered gear assemblies installed therein; each staggered gear assembly includes a first planetary gear, multiple intermediate transition planetary gears, a second planetary gear, and a staggered pin that mesh sequentially, with the first and second planetary gears of adjacent staggered gear assemblies located on the same staggered pin and their axes offset from each other; a first output gear and a second output gear, wherein the first output gear meshes with the first planetary gear in the multiple staggered gear assemblies, and the second output gear meshes with the second planetary gear in the multiple staggered gear assemblies. This invention effectively shortens the axial space of the differential and, by employing multiple spur planetary gears arranged in a staggered manner, enhances its torsional capacity while effectively utilizing its axial space.

Description

Technical Field

[0001] This invention belongs to the technical field of differentials, and specifically relates to a staggered differential. Background Technology

[0002] The new energy vehicle industry is booming, and improving the driving range of vehicles has become a top priority, thus requiring further improvements in the efficiency of electric drive systems. Common methods for improving electric drive efficiency include: reducing component weight, integrating components, and using new lightweight transmission routes. Consequently, the development of electric drive systems is gradually showing the following trends: switching from water-cooled to oil-cooled motors; increasing the continuous output power of motors at high speeds; sharing a cavity between the reducer, motor, and controller; further reducing the number of components such as splines and bearings; achieving integrated development; and gradually transitioning from offset parallel shaft solutions to coaxial planetary gear sets, matching dual motors or other power-split solutions to achieve miniaturization or multi-power integration.

[0003] As a power output component, the core function of a differential is to achieve stable power output when the left and right wheels rotate at different speeds. Common differentials use a bevel gear transmission scheme, which internally includes planetary gears, half-shaft gears, planetary gear washers, half-shaft gear washers, a slotted shaft, and locking pins. This results in a large axial space and makes it difficult to integrate with other gear shaft components, making the differential heavy and affecting the efficiency of electric drive transmission.

[0004] In existing technologies, spur gear planetary gear transmission is generally used instead of bevel gear transmission to shorten axial space and integrate the differential housing with the planetary carrier to reduce weight. However, existing technologies have problems such as simply replacing bevel gears with spur gears, which does not make reasonable use of circumferential space, and the strength and life of each planetary gear are not consistent. In addition, due to the uneven circumferential force on the bevel gears of the differential, the stiffness changes greatly during actual loading, which is not conducive to NVH performance. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a staggered differential, which enhances torsional capacity and effectively utilizes circumferential space by employing multiple spur planetary gears in a staggered arrangement. The new spur planetary gear transmission scheme replaces the traditional bevel gear transmission scheme, thereby enhancing the integration, miniaturization, and lightweight design of the differential, and achieving the goal of improving the efficiency of the electric drive system and increasing the overall vehicle range.

[0006] To achieve the above and other related objectives, the present invention proposes a staggered differential, comprising:

[0007] The differential housing contains multiple staggered gear assemblies.

[0008] The staggered gear assembly includes a first planetary gear, a plurality of intermediate transition planetary gears, a second planetary gear, and a staggered pin. The first planetary gear, the plurality of intermediate transition planetary gears, and the second planetary gear mesh sequentially, and the first planetary gear and the second planetary gear between two adjacent staggered gear assemblies are located on the same staggered pin, and their axes are offset from each other.

[0009] A first output gear and a second output gear, wherein the first output gear meshes with a first planetary gear in one of the plurality of staggered gear assemblies, and the second output gear meshes with a second planetary gear in one of the plurality of staggered gear assemblies.

[0010] In one embodiment of the invention, the positions of the first planetary gear, the plurality of intermediate transition planetary gears, and the second planetary gear gradually shift downward or upward in the same direction parallel to each other on the axis.

[0011] In one embodiment of the present invention, a plurality of gear shafts are provided inside the differential housing, and the intermediate transition planetary gear is mounted on the gear shaft and meshes with the first planetary gear and the second planetary gear.

[0012] In one embodiment of the invention, the staggered pin is rotatably connected to the differential housing.

[0013] In one embodiment of the present invention, the intermediate transition planetary gear includes a left transition planetary gear and a right transition planetary gear, and the first planetary gear, the left transition planetary gear, the right transition planetary gear and the second planetary gear mesh in sequence.

[0014] In one embodiment of the present invention, the differential housing includes a first housing and a second housing, the first housing and the second housing being fixedly connected together to form a receiving cavity, and a plurality of the staggered gear assemblies being located within the receiving cavity.

[0015] In one embodiment of the present invention, a plurality of gear shafts are provided on the inner sides of both the first housing and the second housing. The left-hand planetary gear is mounted on the gear shaft on the inner side of the first housing, and the right-hand planetary gear is mounted on the gear shaft on the inner side of the second housing.

[0016] In one embodiment of the invention, a gear ring is further included, which is located on the outer circumference of the differential housing and is fixedly connected to the differential housing.

[0017] In one embodiment of the present invention, the staggered pin includes a connecting plate, a first pin, and a second pin. The first pin and the second pin are located on both sides of the connecting plate and are fixedly connected to the connecting plate. The axes of the first pin and the second pin are staggered and parallel to each other.

[0018] In one embodiment of the present invention, the first planetary gear is mounted on the first pin and meshes with the first output gear for transmission, and the second planetary gear is mounted on the second pin and meshes with the second output gear for transmission.

[0019] This invention proposes a staggered differential, which distributes multiple planetary gears evenly along the circumference, so that the distribution circle diameter of the planetary gears can be made smaller, and the parameters of each planetary gear are the same, resulting in uniform load distribution.

[0020] This invention proposes a staggered differential, which divides the differential housing into two parts: a first housing and a second housing. The two parts are fixedly connected together by welding. The first housing can be welded to the gear ring, and the gear ring is supported on the differential housing, which effectively reduces gear load skew and improves NVH performance.

[0021] This invention proposes a staggered differential, which replaces the traditional bevel gear transmission with a spur gear transmission, and effectively shortens the axial space of the differential by using multiple spur planetary gears arranged in a staggered manner along the axial direction. Furthermore, by using multiple spur planetary gears arranged in a staggered manner, the torsional capacity is enhanced while the axial space is effectively utilized. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an exploded structural diagram of a staggered differential in one embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the assembly structure of multiple staggered gear sets in one embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the assembly structure of a single staggered gear set in one embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the assembly structure of the staggered pin with the first planetary gear and the second planetary gear in one embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of a staggered differential in one embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of the structure of a staggered differential in one embodiment of the present invention when arranged in a parallel shaft configuration.

[0029] Figure 7 This is a schematic diagram of the structure of a staggered differential in one embodiment of the present invention when it is arranged in a coaxial configuration.

[0030] Label Explanation:

[0031] A staggered differential 100; a differential housing 10; a staggered gear assembly 20; a first output gear 30; a second output gear 40; a first planetary gear 201; a second planetary gear 202; a staggered pin 203; a connecting plate 2031; a first pin 2032; a second pin 2033; a left-hand rotating planetary gear 204; a right-hand rotating planetary gear 205; a first housing 101; a second housing 102; a gear shaft 103; an external gear ring 1001; an output gear 1002; and an internal gear ring 1003. Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0033] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] Please see Figures 1 to 5As shown, this invention proposes a staggered differential to improve upon the problems in the prior art where only spur gears are used instead of bevel gears, which does not make reasonable use of axial space and results in inconsistent strength and lifespan of the planetary gears. It also addresses the issue that the bevel gears in the differential experience uneven circumferential stress, leading to significant stiffness variations during actual loading, which is detrimental to NVH performance. Specifically, the staggered differential 100 includes a differential housing 10, multiple staggered gear assemblies 20, a first output gear 30, and a second output gear 40. The staggered gear assemblies 20 are installed within the differential housing 10. The first output gear 30 and the second output gear 40 are located on opposite sides of the staggered gear assembly 20 and mesh with the first planetary gear 201 and the second planetary gear 202 within the staggered gear assembly 20.

[0035] Please see Figures 1 to 4 As shown, in this embodiment, the staggered gear assembly 20 includes a first planetary gear 201, a second planetary gear 202, a staggered pin 203, and a plurality of intermediate transition planetary gears. The first planetary gear 201, the plurality of intermediate transition planetary gears, and the second planetary gear 202 mesh sequentially. The first planetary gear 201 and the second planetary gear 202 between two adjacent staggered gear assemblies 20 are located on the same staggered pin 203, and their axes are offset from each other. That is, the first planetary gear 201 and the second planetary gear 202 located on the same staggered pin 203 are arranged in a staggered manner to effectively utilize the circumferential space within the differential housing 10.

[0036] Please see Figures 1 to 4 As shown, in this embodiment, multiple staggered gear assemblies 20 are connected end-to-end by staggered pins 203. This means that by placing the first planetary gear 201 and the second planetary gear 202 between two adjacent staggered gear assemblies 20 on the same staggered pin 203, they surround a ring structure. The first output gear 30 and the second output gear 40 are located at the middle positions on both sides of this ring structure and mesh with the first planetary gear 201 and the second planetary gear 202, respectively. It should be noted that by evenly distributing multiple planetary gears circumferentially and staggering their arrangement, the distribution circle diameter of the planetary gears can be made smaller, resulting in a compact structure and effective utilization of circumferential space. It should also be noted that in this embodiment, the parameters of the first planetary gear 201, the second planetary gear 202, and multiple intermediate transition planetary gears are the same, resulting in uniform load distribution and reducing the difference in fatigue safety factors among the individual planetary gears.

[0037] Please see Figures 1 to 4As shown, in this embodiment, the staggered pin 203 includes a connecting plate 2031, a first pin 2032, and a second pin 2033. The first pin 2032 and the second pin 2033 are located on both sides of the connecting plate 2031, and one end of each pin is fixedly connected to the connecting plate 2031. The axes of the first pin 2032 and the second pin 2033 are offset from each other and parallel. The first planetary gear 201 is mounted on the first pin 2032, and the second planetary gear 202 is mounted on the second pin 2033, so that the first planetary gear 201 and the second planetary gear 202 are staggered from each other, so that they can effectively utilize the circumferential space within the differential housing 10. It should be noted that the staggered pin 203 is an integral structure, that is, the connecting plate 2031, the first pin 2032, and the second pin 2033 are integrally formed.

[0038] Please see Figures 1 to 4 As shown, it should also be noted that in the same staggered gear assembly 20, there is a certain height difference between the first planetary gear 201 and the second planetary gear 202 along their axial direction, and they are connected by a plurality of intermediate transition planetary gears. That is, the positions of the first planetary gear 201, the plurality of intermediate transition planetary gears and the second planetary gear 202 gradually move down or up in the same direction parallel to the axis. The first planetary gear 201, the plurality of intermediate transition planetary gears and the second planetary gear 202 are all spur gears and are staggered along their axial direction so as to effectively shorten their axial space.

[0039] Please see Figures 1 to 4 As shown, it should be noted that the number of intermediate planetary gears must be set to ensure that the first planetary gear 201 and the second planetary gear 202 meshing with it rotate in opposite directions. Please refer to [link / reference]. Figure 1As shown, in this embodiment, the number of intermediate planetary gears is set to two, including a left planetary gear 204 and a right planetary gear 205. The first planetary gear 201, the left planetary gear 204, the right planetary gear 205, and the second planetary gear 202 mesh sequentially. Specifically, the first planetary gear 201 is mounted on the first pin 2032 on the staggered pin 203 and meshes with the upper half of the gear surface of the left planetary gear 204. The upper half of the gear surface of the right planetary gear 204 meshes with the lower half of the gear surface of the left planetary gear 204. The second planetary gear 202 meshes with the lower half of the gear surface of the right planetary gear 204. For details, please refer to [link to relevant documentation]. Figure 3 As shown, Figure 3 The diagram shows a staggered gear assembly 20, in which the first planetary gear 201, the left-hand planetary gear 204, the right-hand planetary gear 205, and the second planetary gear 202 are meshed together in sequence, and their positions gradually move downwards in the same direction parallel to the axis to achieve mutual misalignment, so that the spur planetary gears are arranged in a staggered manner, thereby enhancing the torsional capacity of the structure and effectively utilizing the axial space.

[0040] Please see Figures 1 to 4 As shown, in this embodiment, the first planetary gears 201 in the plurality of staggered gear assemblies 20 are located on the same plane and mesh with the first output gear 30 for transmission. The second planetary gears 202 in the plurality of staggered gear assemblies 20 are located on the same plane but not on the same plane as the first planetary gears 201. The second planetary gears 202 in the plurality of staggered gear assemblies 20 mesh with the second output gear 40 for transmission. It should be noted that in this embodiment, the first planetary gears 201 and the second planetary gears 202 in the plurality of staggered gear assemblies 20 rotate in opposite directions, thereby causing the first output gear 30 and the second output gear 40 to rotate in opposite directions to achieve differential speed. It should also be noted that because the first planetary gears 201 and the second gears 202 have the same shape and are staggered in arrangement, the first output gear 30 and the second output gear 40 connected to them can be set to have the same shape.

[0041] Please see Figures 1 to 4 As shown, in this embodiment, the differential housing 10 includes a first housing 101 and a second housing 102. The first housing 101 and the second housing 102 can be fixedly connected together by welding, for example, to form a receiving cavity, in which a plurality of staggered gear assemblies 20 are located.

[0042] Please see Figures 1 to 4 As shown, in this embodiment, a plurality of gear shafts 103 are provided on the inner side of both the first housing 101 and the second housing 102, that is, the gear shafts 103 are located in the receiving cavity. The left swivel planetary gear 204 is mounted on the gear shaft 103 on the inner side of the first housing 101, and the right swivel planetary gear 205 is mounted on the gear shaft 103 on the inner side of the second housing 102. In this embodiment, a plurality of staggered pins 203 are provided in the receiving cavity. The number of staggered pins 203 is the same as the number of staggered gear assemblies 20. The plurality of staggered pins 203 are installed between the first housing 101 and the second housing 102, and a first planetary gear 201 and a second planetary gear 202 are installed on each of the plurality of staggered pins 203. When the installation is completed, the left-hand rotating planetary gear 204 installed on the first housing 101 meshes with the first planetary gear 201 on the plurality of staggered pins 203, and the right-hand rotating planetary gear 205 installed on the second housing 102 meshes with the second planetary gear 202 on the plurality of staggered pins 203 to realize transmission.

[0043] Please see Figures 1 to 4 As shown, in this embodiment, the staggered differential 100 includes three staggered gear assemblies 20, and each staggered gear assembly 20 includes a first planetary gear 201, a left-hand rotating planetary gear 204, a right-hand rotating planetary gear 205 and a second planetary gear 202 that mesh in sequence.

[0044] Please see Figures 1 to 5As shown, both the first housing 101 and the second housing 102 are provided with three gear shafts 103, and the gear shafts 103 on the first housing 101 and the second housing 102 are staggered, that is, the axes of the gear shafts 103 are parallel to each other and do not coincide. During installation, the first planetary gear 201 and the second planetary gear 202 are first installed on the same staggered pin 203, then three planetary gears 204 are installed on the three gear shafts 103 inside the first housing 102, and three right-hand planetary gears 205 are installed on the three gear shafts 103 inside the second housing 102. Finally, the three staggered pins 203 on which the first planetary gears 201 and the second planetary gears 202 are installed are installed on the first housing 101 and the second housing 102. The first planetary gear 201 is placed close to the first housing 101, and the second planetary gear 202 is placed close to the second housing 102. Then, the first output gear 30 and the second output gear 40 are respectively installed on the first housing 101 and the second housing 102. Finally, the first housing 101 and the second housing 102 are fixedly connected together so that the first planetary gear 201, the left rotating planetary gear 204, the right rotating planetary gear 205 and the second planetary gear 202 mesh in sequence, and the multiple staggered gear assemblies 20 are connected end to end. At the same time, the first output gear 30 and the second output gear 40 mesh with the first planetary gear 201 and the second planetary gear 202 respectively.

[0045] Please see Figure 1 , Figure 6 and Figure 7 As shown, in this embodiment, a gear ring is also included. The gear ring is located on the outer circumference of the differential housing 10 and is fixedly connected to the differential housing 10. Specifically, the gear ring is located on the outer circumference of the first housing 101 and is fixedly connected to the first housing 101. The gear ring is used to connect with the gear in the reducer to transmit power to the differential housing 10. It should be noted that the staggered differential 100 can be compatible with various transmission arrangements, including parallel shaft arrangements and coaxial arrangements.

[0046] Please see Figure 1 and Figure 6As shown, when the staggered differential 100 is applied in a parallel shaft arrangement, the gear ring is an external gear ring 1001. The external gear ring 1001 is fixedly connected to the first housing 101 and meshes with the output gear 1002 of the reducer to transmit power to the external gear ring 1001. Power is input from the external gear ring 1001, transmitted through the differential housing 10 to the internal staggered gear assembly 20, and finally output through the first output gear 30 and the second output gear 40. During differential operation, the first output gear 30 and the second output gear 40 rotate in opposite directions, causing a speed difference between the left and right wheels, thus completing the differential operation.

[0047] Please see Figure 1 and Figure 7 As shown, when the staggered differential 100 is applied in a coaxial arrangement, the gear ring is an internal gear ring 1003. The internal gear ring 1003 is fixedly connected to the first housing 101 and meshes with the output gear of the reducer to transmit power to the internal gear ring 1003. Power is input from the internal gear ring 1003, transmitted through the differential housing 10 to the internal staggered gear assembly 20, and finally output through the first output gear 30 and the second output gear 40. During differential operation, the first output gear 30 and the second output gear 40 rotate in opposite directions, causing a speed difference between the left and right wheels, thus completing the differential operation.

[0048] This invention proposes a staggered differential, which distributes multiple planetary gears evenly along the circumference, so that the distribution circle diameter of the planetary gears can be made smaller, and the parameters of each planetary gear are the same, resulting in uniform load distribution.

[0049] This invention proposes a staggered differential, which divides the differential housing into two parts: a first housing and a second housing. The two parts are fixedly connected together by welding. The first housing can be welded to the gear ring, and the gear ring is supported on the differential housing, which effectively reduces gear load skew and improves NVH performance.

[0050] This invention proposes a staggered differential, which replaces the traditional bevel gear transmission with a spur gear transmission, and effectively shortens the axial space of the differential by using multiple spur planetary gears arranged in a staggered manner along the axial direction. Furthermore, by using multiple spur planetary gears arranged in a staggered manner, the torsional capacity is enhanced while the axial space is effectively utilized.

[0051] The above description is merely a preferred embodiment of this application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in this application is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept. For example, technical solutions formed by replacing the above-mentioned features with technical features with similar functions disclosed in this application (but not limited to) each other.

[0052] Apart from the technical features described in the specification, the other technical features are known to those skilled in the art. To highlight the innovative features of this invention, the other technical features will not be described in detail here.

Claims

1. A staggered differential, characterized in that, include: A differential housing in which multiple staggered gear assemblies are installed; the differential housing includes a first housing and a second housing, the first housing and the second housing being connected together to form a receiving cavity, and the multiple staggered gear assemblies being located within the receiving cavity; The staggered gear assembly includes a first planetary gear, a plurality of intermediate transition planetary gears, a second planetary gear, and a staggered pin. The first planetary gear, the plurality of intermediate transition planetary gears, and the second planetary gear mesh sequentially, and the first planetary gear and the second planetary gear between two adjacent staggered gear assemblies are located on the same staggered pin, and their axes are offset from each other. A first output gear and a second output gear, wherein the first output gear meshes with a first planetary gear in one of the plurality of staggered gear assemblies, and the second output gear meshes with a second planetary gear in one of the plurality of staggered gear assemblies; The staggered pin includes a connecting plate, a first pin, and a second pin. The first pin and the second pin are located on both sides of the connecting plate and are fixedly connected to the connecting plate. The axes of the first pin and the second pin are staggered and parallel to each other. The first planetary gear is mounted on the first pin and meshes with the first output gear for transmission. The second planetary gear is mounted on the second pin and meshes with the second output gear for transmission.

2. The staggered differential according to claim 1, characterized in that, The positions of the first planetary gear, the plurality of intermediate transition planetary gears, and the second planetary gear gradually shift downward or upward in the same direction parallel to each other on the axis.

3. The staggered differential according to claim 1, characterized in that, The differential housing contains multiple gear shafts, and the intermediate planetary gear is mounted on the gear shaft and meshes with the first planetary gear and the second planetary gear.

4. The staggered differential according to claim 1, characterized in that, The staggered pin is rotatably connected to the differential housing.

5. The staggered differential according to claim 1, characterized in that, The intermediate transition planetary gear includes a left transition planetary gear and a right transition planetary gear, and the first planetary gear, the left transition planetary gear, the right transition planetary gear and the second planetary gear mesh in sequence.

6. The staggered differential according to claim 5, characterized in that, Both the first housing and the second housing have multiple gear shafts on their inner sides. The left-hand planetary gear is mounted on the gear shaft inside the first housing, and the right-hand planetary gear is mounted on the gear shaft inside the second housing.

7. The staggered differential according to claim 1, characterized in that, It also includes a gear ring, which is located on the outer circumference of the differential housing and is fixedly connected to the differential housing.

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