Elastic power-assisted gear shifting actuator, transmission and electric drive axle

Abstract

This invention relates to an elastic power-assisted shift actuator, a transmission, and an electric drive axle. The invention includes a shift drum with a pre-grooved groove on its outer circumferential surface; a drive unit connected to the shift drum and providing torque for the shift drum to rotate about its central axis; a shift fork including a transmission part, the shift fork being rotatable about a central axis perpendicular to the central axis of the shift drum; and an elastic sliding device disposed on one side of the shift drum, the elastic sliding device including a guide assembly, two sliders axially movable through the guide assembly, and an elastic element disposed between the two sliders, each slider cooperating with the groove and including an actuating part cooperating with the transmission part. This invention can reduce the impact generated during gear shifting in automotive transmissions and electric drive axles, reduce wear on the shift fork during gear shifting, improve the success rate of a single gear shift, and ensure fast, smooth, and accurate gear shifting during vehicle operation.

Description

Technical Field

[0001] This invention relates to the field of transmission system technology, and in particular to elastic power-assisted shift actuators, transmissions and electric drive axles. Background Technology

[0002] The shift actuator is a core component of the automotive transmission system, responsible for executing shifting actions within the gearbox according to commands from the shift controller.

[0003] Currently, shift actuators typically rely on pneumatic, hydraulic, or traditional mechanical methods to operate shift forks in order to switch gears in a transmission or electric drive axle. However, with the rapid growth of the new energy vehicle market, if the transmission uses a pneumatic or hydraulic system to drive the shift forks, additional pneumatic or hydraulic equipment must be installed, which undoubtedly increases the overall vehicle manufacturing cost. At the same time, shift forks using traditional mechanical drive methods also face the problem of accelerated wear and tear on the shift forks and connecting components. Summary of the Invention

[0004] To address this, the present invention provides an elastic power-assisted shift actuator, which can reduce the impact generated during the shifting process of automotive gearboxes and electric drive axles, and reduce the wear of shift forks during the shifting process, thereby improving the success rate of shifting in one go and ensuring that the vehicle can shift quickly, smoothly and accurately during driving.

[0005] To solve the above-mentioned technical problems, the present invention provides an elastic power-assisted shift actuator, comprising:

[0006] The shift drum has a groove with a preset trajectory on its outer circumference.

[0007] A drive unit is connected to the shift drum and provides the torque for rotating the shift drum about its central axis;

[0008] A shift fork, including a transmission part, is rotatable about a central axis perpendicular to the central axis of the shift drum;

[0009] An elastic sliding device is disposed on one side of the shift drum. The elastic sliding device includes a guide assembly, two sliders that move axially through the guide assembly, and an elastic element disposed between the two sliders. Each slider cooperates with the profile groove and includes an actuating part that cooperates with the transmission part.

[0010] When the shift drum rotates, the slider can move axially through the profile groove, and through the cooperation of the actuation part and the transmission part, it can provide a force to drive the shift fork to rotate around the central axis.

[0011] When one of the sliders is stationary relative to the guide assembly and the shift drum continues to rotate, the elastic element can be axially compressed and generate an axial elastic force on the shift fork to accelerate the shifting.

[0012] In one embodiment of the present invention, the actuating part includes a driving surface, and the transmission part includes a transmission surface that slides in contact with the driving surface. When the slider moves axially, the sliding contact between the driving surface and the transmission surface can be converted into a force that causes the shift fork to rotate about the central axis.

[0013] In one embodiment of the present invention, the driving surface and the transmission surface are in sliding fit through an inclined curved surface.

[0014] In one embodiment of the present invention, the driving surface and the transmission surface are in close contact with each other when they slide relative to each other.

[0015] In one embodiment of the present invention, the driving surface includes a smoothly transitioning upper curved surface and a lower curved surface, the guiding assembly includes two guide shafts, the elastic element includes a spring sleeved on the two guide shafts and abutting against the two sliders respectively, the upper curved surface and the lower curved surface are respectively provided with through holes for each guide shaft to pass through, the upper curved surface and the lower curved surface are respectively concave and convex in the outward direction along the axial direction of the guide shaft, and the driving surface is radially inclined in the radial direction along the guide shaft.

[0016] In one embodiment of the invention, the shift fork includes a shift fork crossarm and shift fork longitudinal arms extending to both ends of the shift fork crossarm. The shift fork crossarm extends with a transmission block. One side of the transmission block opposite to the drive surface is partially configured as the transmission surface. The transmission surface is in close contact with the lower curved surface. The thickness of the portion of the slider including the lower curved surface is greater than the thickness of the portion of the slider including the upper curved surface. The transmission block includes a clearance groove through which the guide shaft passes.

[0017] In one embodiment of the present invention, a bracket assembly is further included, the bracket assembly including a first bracket and a second bracket disposed opposite to each other, the two ends of the shift drum being rotatably connected to the first bracket and the second bracket respectively via a first bearing and a second bearing, and the two ends of each guide shaft being respectively mounted on the first bracket and the second bracket.

[0018] In one embodiment of the present invention, the two fork arms are provided with pins at the central axis position, and the forks are rotatable around the pins.

[0019] The present invention also provides a transmission including the aforementioned elastic power-assisted shift actuator.

[0020] The present invention also provides an electric drive bridge, including the aforementioned elastic power-assisted shift actuator.

[0021] The technical solution of the present invention has the following advantages compared with the prior art:

[0022] The elastic power-assisted shift actuator, transmission, and electric drive axle of this invention achieve rapid pushing of the shift fork through the compression and release of the elastic element, thereby completing the gear shifting operation. This can improve the success rate of shifting in one go, reduce the impact during the shifting process, reduce shift fork wear, and ensure the accuracy and smoothness of shifting.

[0023] This shift actuator simplifies the internal structure of the gearbox, reduces its size, and lowers production costs by integrating the shift fork.

[0024] This shift actuator can be applied to transmissions or electric drive axles. The shift fork cooperates with the gearbox shift shaft sleeve of the electric drive axle or transmission, making it suitable for different types of automobiles and possessing high versatility and practicality. Attached Figure Description

[0025] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the overall structure of the elastic power-assisted shifting actuator of the present invention.

[0027] Figure 2 This is an exploded view of the overall structure of the elastic power-assisted shifting actuator of the present invention.

[0028] Explanation of reference numerals on the accompanying drawings:

[0029] 1. Shift drum; 11. Profile groove;

[0030] 2. Shift fork; 21. Transmission block; 21a. Transmission part; 211. Transmission surface; 212. Relief groove; 22. Shift fork cross arm; 23. Shift fork longitudinal arm;

[0031] 3. Elastic sliding device; 31. Guide assembly; 311. Guide shaft; 32. Slider; 32a. Actuating part; 321. Driving surface; 322. Driving pin; 33. Elastic element;

[0032] 4. Support assembly; 41a. First support; 41b. Second support; 42a. First bearing; 42b. Second bearing;

[0033] 5. Pins. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0035] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0036] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0037] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0038] Reference Figure 1 and Figure 2 As shown, a flexible power-assisted shift actuator includes:

[0039] The shift drum 1 has a groove 11 with a preset trajectory on its outer circumferential surface;

[0040] A drive unit is connected to the shift drum 1 and provides the torque for the shift drum 1 to rotate about the central axis;

[0041] The shift fork 2 includes a transmission part 21a, and the shift fork 2 is rotatable about a central axis perpendicular to the central axis of the shift drum 1.

[0042] An elastic sliding device 3 is disposed on one side of the shift drum 1. The elastic sliding device 3 includes a guide assembly 31, two sliders 32 that move axially through the guide assembly 31, and an elastic element 33 disposed between the two sliders 32. Each slider 32 cooperates with the profile groove 11 and includes an actuating part 32a that cooperates with the transmission part 21a.

[0043] When the shift drum 1 rotates, the slider 32 can move axially through the profile groove 11. Through the cooperation of the actuating part 32a and the transmission part 21a, a force is provided to drive the shift fork 2 to rotate around the central axis. When one of the sliders 32 is stationary relative to the guide assembly 31 and the shift drum 1 continues to rotate, the elastic element 33 can be axially compressed and generate an axial elastic force on the shift fork 2 to accelerate the shifting.

[0044] The design of the aforementioned elastic power-assisted shift actuator buffers the impact force during the shifting process and reduces the wear of the shift fork 2 during shifting. The auxiliary force provided by the elastic element 33 can improve the success rate of a single shift and reduce potential malfunctions caused by unsuccessful shifting. It achieves fast and smooth shifting, ensuring the comfort and shifting accuracy of the vehicle during driving.

[0045] In some embodiments, the actuating part 32a includes a driving surface 321, and the transmission part 21a includes a transmission surface 211 that slides in contact with the driving surface 321. When the slider 32 moves axially, the sliding contact between the driving surface 321 and the transmission surface 211 can be converted into a force that causes the shift fork 2 to rotate around the central axis.

[0046] To achieve the above functions, the driving surface 321 and the transmission surface 211 are in sliding engagement via an inclined curved surface. Furthermore, the driving surface 321 and the transmission surface 211 are in close contact with each other during relative sliding to ensure the efficiency and accuracy of power transmission, reduce power loss caused by gaps, prevent the shift fork 2 from jumping during gear shifting, which would affect the shifting quality, and provide a larger contact area and support surface to withstand the larger load generated between the driving surface 321 and the transmission surface 211 when the shift drum 1 rotates, thus ensuring the stability and durability of the slider 32.

[0047] Specifically, the driving surface 321 includes a smoothly transitioning upper and lower curved surface, the guide assembly 31 includes two guide shafts 311, and the elastic element 33 includes a spring sleeved on the two guide shafts 311 and abutting against the two sliders 32 respectively. By pre-pressing the spring between the two sliders 32, each slider 32 extends with a driving pin 322 that penetrates into the groove 11, ensuring a stable fit between each slider 32 and the groove 11 of the shift drum 1. The upper and lower curved surfaces are respectively provided with through holes for each guide shaft 311 to pass through. Along the axial direction of the guide shaft 311, the upper and lower curved surfaces are concave and convex respectively, and along the radial direction of the guide shaft 311, the driving surface 321 is radially inclined. The concave and convex shapes of the upper and lower curved surfaces enhance the mechanical properties of the component, ensuring power transmission and response speed.

[0048] The shift fork 2 includes a shift fork cross arm 22 and shift fork longitudinal arms 23 extending from both ends of the shift fork cross arm 22. A transmission block 21 extends from the shift fork cross arm 22. One side of the transmission block 21 opposite the driving surface 321 is partially constructed as the transmission surface 211. The transmission surface 211 is in close contact with the lower curved surface. The thickness of the portion of the slider 32 including the lower curved surface is greater than the thickness of the portion of the slider 32 including the upper curved surface, increasing the pressure resistance of the slider 32 and preventing localized fatigue or damage due to force concentration. The transmission block 21 includes a clearance groove 212 through which the guide shaft 311 passes.

[0049] Therefore, the driving surface 321 and the transmission surface 211 are connected by a sliding engagement of inclined curved surfaces. When the slider 32 moves axially, the linear motion is converted into the rotation of the shift fork 2 through the inclined curved surfaces, thereby achieving high-efficiency power transmission and reducing friction.

[0050] In some embodiments, the system further includes a support assembly 4, which includes a first support 41a and a second support 41b disposed opposite to each other. The two axial ends of the shift drum 1 are rotatably connected to the first support 41a and the second support 41b via a first bearing 42a and a second bearing 42b, respectively. The two axial ends of each guide shaft 311 are respectively mounted on the first support 41a and the second support 41b. The guide shafts 311 are supported by the first support 41a and the second support 41b, ensuring support stability.

[0051] In some embodiments, the two fork arms 23 are provided with pins 5 at the central axis position, and the fork 2 is rotatable around the pins 5.

[0052] In some embodiments, the shift drum 1 of the elastic power-assisted shift actuator is rotated by a connected drive device, which may be a geared motor or similar device. The geared motor is connected to a gear set, which is splined to the shift drum 1 to drive the shift rotation.

[0053] This flexible power shift actuator can be applied to a transmission or electric drive axle, and is engaged with the gearbox shift sleeve of the electric drive axle or transmission via the shift fork 2.

[0054] The working principle of this invention is as follows: A command is issued by the control system, which drives the shift drum to rotate via the drive device. The special groove 11 on the shift drum 1 drives two shift sliders 32 to move axially, thereby causing the shift fork 2 to rotate around the pin 5, pushing the gearbox inner bushing to complete the shifting task. Furthermore, because there is a possibility of the bushing teeth hitting each other when the shift fork 2 drives the electric drive axle or gearbox bushing, causing one side of the slider 32 to stop axial movement while the other side continues axial movement, the spring between the two sliders 32 will be compressed. When the teeth of the electric drive axle or gearbox bushing are misaligned, the compressed spring force will be released, providing an acceleration to push the shift fork 2. The shift fork 2 pushes the bushing into engagement quickly, completing the shift. By integrating the shift fork 2 with the shift drum 1, this elastic power-assisted shifter can achieve fast, smooth, and accurate gearbox or electric drive axle shifting, and improve the success rate of a single shift. By compressing and releasing the elastic element 33, the shift fork 2 is pushed quickly to complete the gear shifting operation. This reduces the impact during the shifting process, reduces the wear of the shift fork 2, and ensures the accuracy and smoothness of the shifting.

[0055] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A spring-assisted gear shift actuator, characterized in that include: The shift drum (1) has a groove (11) with a preset trajectory on its outer circumferential surface. A drive unit is connected to the shift drum (1) and provides the torque for the shift drum (1) to rotate about the central axis; The shift fork (2) includes a transmission part (21a) and the shift fork (2) is rotatable about a central axis perpendicular to the central axis of the shift drum (1); An elastic sliding device (3) is disposed on one side of the shift drum (1). The elastic sliding device (3) includes a guide assembly (31), two sliders (32) that move axially through the guide assembly (31), and an elastic element (33) disposed between the two sliders (32). Each slider (32) cooperates with the profile groove (11) and includes an actuating part (32a) that cooperates with the transmission part (21a). When the shift drum (1) rotates, the slider (32) can move axially through the profile groove (11), and through the cooperation of the actuating part (32a) and the transmission part (21a), it provides a force to drive the shift fork (2) to rotate around the central axis. When one of the sliders (32) is stationary relative to the guide assembly (31) and the shift drum (1) continues to rotate, the elastic element (33) can be axially compressed and generate an axial elastic force on the shift fork (2) to accelerate the shifting. The actuating part (32a) includes a driving surface (321), and the transmission part (21a) includes a transmission surface (211) that slides in contact with the driving surface (321). When the slider (32) moves axially, the sliding contact between the driving surface (321) and the transmission surface (211) can be converted into a force that causes the fork (2) to rotate around the central axis. The driving surface (321) and the transmission surface (211) are in sliding fit through an inclined curved surface; The driving surface (321) and the transmission surface (211) are in close contact with each other when they slide relative to each other; The driving surface (321) includes a smoothly transitioning upper curved surface and a lower curved surface. The guide assembly (31) includes two guide shafts (311). The elastic element (33) includes a spring sleeved on the two guide shafts (311) and abutting against the two sliders (32) respectively. The upper curved surface and the lower curved surface are respectively provided with through holes for each guide shaft (311) to pass through. Along the axial direction of the guide shaft (311), the upper curved surface and the lower curved surface are respectively concave and convex. Along the radial direction of the guide shaft (311), the driving surface (321) is radially inclined. The fork (2) includes a fork cross arm (22) and fork longitudinal arms (23) extending to both ends of the fork cross arm (22); The two fork arms (23) are provided with pins (5) at the central axis position, and the fork (2) can rotate around the pins (5).

2. The elastic power-assisted shift actuator according to claim 1, characterized in that, The fork crossarm (22) extends with a transmission block (21), one side of the transmission block (21) opposite the drive surface (321) being partially constructed as the transmission surface (211), the transmission surface (211) being in close contact with the lower curved surface, the thickness of the portion of the slider (32) including the lower curved surface being greater than the portion of the slider (32) including the upper curved surface, and the transmission block (21) including a relief groove (212) through which the guide shaft (311) passes.

3. The elastic power-assisted shift actuator according to claim 1, characterized in that, It also includes a bracket assembly (4), which includes a first bracket (41a) and a second bracket (41b) arranged opposite to each other. The two ends of the shift drum (1) are rotatably connected to the first bracket (41a) and the second bracket (41b) respectively through a first bearing (42a) and a second bearing (42b). The two ends of each guide shaft (311) are respectively installed on the first bracket (41a) and the second bracket (41b).

4. A transmission, characterized in that, Includes the elastic power-assisted shift actuator as described in any one of claims 1-3.

5. An electric drive bridge, characterized in that, Includes the elastic power-assisted shift actuator as described in any one of claims 1-3.

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