Torque limiter and gearbox

Abstract

The present disclosure relates to a torque limiter and a gearbox, the torque limiter comprising: an outer ring provided with an annular outer ring contact plate on the radially inner side, an axial end surface of the outer ring contact plate being provided with a first groove distributed in the circumferential direction; an inner ring provided with an inner ring contact plate axially spaced from the outer ring contact plate on the radially outer side, the inner ring contact plate being in torque transmission connection with the inner ring in an axially movable manner, and an axial end surface of the inner ring contact plate being formed with a second groove corresponding to the first groove; a plurality of balls clamped between the first groove and the second groove; and an elastic element axially pressing the inner ring contact plate to axially clamp the balls between the inner ring contact plate and the outer ring contact plate; wherein when the transmitted torque exceeds a threshold value, the second groove of the inner ring contact plate pushes the balls to climb, so that the inner ring contact plate moves axially against the pre-tightening force of the elastic element, causing the balls to be out of the constraint of the first groove and the second groove and interrupt the torque transmission; when the torque is restored, the elastic element resets the inner ring contact plate and rebuilds the torque transmission path.

Description

Technical Field

[0001] This utility model relates to the field of torque limiting technology, and in particular to a torque limiter and a gearbox. Background Technology

[0002] Hybrid vehicles and pure electric vehicles face severe wheel-end impact load challenges under certain operating conditions.

[0003] In hybrid vehicles operating in direct-drive mode or with in-wheel motor architecture, the impact load generated at the wheels directly acts on the transmission system when the vehicle accelerates rapidly or traverses bumpy roads under ABS anti-lock braking conditions. Many related technologies use clutch slippage to limit torque, but this solution only protects against impact loads from the engine to the clutch and cannot effectively prevent reverse impacts from the wheels to the transmission. Some hybrid transmissions, due to cost and space constraints, have eliminated the clutch structure, resulting in the transmission system completely losing its overload protection capability.

[0004] Because pure electric vehicles lack a clutch structure, their transmission systems are constantly exposed to the risk of wheel-end impacts. Especially under conditions of rapid acceleration and ABS braking, impact loads can easily lead to mechanical failures such as driveshaft breakage and gear failure. Currently, heavy-duty pure electric vehicles are frequently experiencing rear axle failures such as broken axles and broken gears under harsh road conditions.

[0005] Traditional torque limiters (including clutch-type and switch-type) suffer from drawbacks such as complex structure and insufficient reliability. Currently, there is a lack of mature solutions for integrating torque limiters into the transmissions or reduction gearboxes of pure electric drive systems. This technological status quo leads to the long-term uncontrollable mechanical overload risk in the transmission systems of hybrid and pure electric vehicles. Therefore, there is an urgent need to develop a torque limiting device that can bidirectionally block impact loads and is suitable for transmission integration. Utility Model Content

[0006] To overcome the problems existing in related technologies, this disclosure provides a torque limiting gear and a gearbox. The torque limiting gear can bidirectionally block impact loads and is suitable for integration into a gearbox or reduction gear.

[0007] According to a first aspect of the present disclosure, a torque limiter is provided, comprising: an outer ring having an annular outer ring contact plate radially inward, the axial end face of the outer ring contact plate having a first groove distributed circumferentially; an inner ring having an inner ring contact plate radially outward and axially spaced from the outer ring contact plate, the inner ring contact plate being axially movably connected to the inner ring for torque transmission, and the axial end face of the inner ring contact plate forming a second groove corresponding to the first groove; a plurality of balls sandwiched between the first groove and the second groove; an elastic element axially pressing the inner ring contact plate so that the inner ring contact plate and the outer ring contact plate axially clamp the balls; wherein, when the transmitted torque exceeds a threshold, the second groove of the inner ring contact plate pushes the balls to rise, causing the inner ring contact plate to move axially against the preload force of the elastic element, resulting in the balls disengaging from the first groove or the second groove constraint and interrupting the torque transmission; when the torque recovers, the elastic element resets the inner ring contact plate and reconstructs the torque transmission path.

[0008] In some embodiments, the inner ring has a first baffle extending radially outward at its first axial end and a second baffle at its second axial end; the first baffle and the second baffle abut against the two axial ends of the outer ring respectively to limit the axial position of the outer ring.

[0009] In some embodiments, the first baffle is integrally formed with the inner ring, the second baffle is a detachable clamping nut, the second end of the inner ring is provided with an external thread, and the clamping nut is threadedly connected to the second end of the inner ring through the external thread.

[0010] In some embodiments, a first stepped shoulder and a second stepped shoulder are formed at both axial ends of the outer ring, respectively; the radial outer end of the first baffle abuts against the first stepped shoulder, and the radial outer end of the second baffle abuts against the second stepped shoulder; wherein the axial outer surfaces of the first baffle and the second baffle are coplanar with the corresponding axial end surfaces of the outer ring.

[0011] In some embodiments, the outer ring contact plate is integrally formed on the radially inner side of the outer ring, and the axial end face of the outer ring contact plate away from the first groove abuts against the first baffle of the inner ring.

[0012] In some embodiments, the second axial end of the inner ring is provided with a plurality of radially protruding bosses evenly distributed circumferentially, the bosses being disposed on the axial inner end of the external thread; the inner ring contact plate is provided with an axial groove corresponding to the number of bosses on its radial inner side, wherein the bosses cooperate with the axial grooves to allow the inner ring contact plate to be axially slidably connected to the inner ring for torque transmission.

[0013] In some embodiments, the elastic element is an annular elastic element, and the elastic element abuts axially between the second baffle and the inner ring contact plate.

[0014] In some embodiments, the elastic element includes a first elastic element and a second elastic element coaxially disposed, wherein the outer diameter of the second elastic element is smaller than the inner diameter of the first elastic element, and the second elastic element is coaxially sleeved within the first elastic element.

[0015] In some embodiments, the outer circumferential surface of the outer ring is provided with a gear structure for meshing with the gear system of the gearbox; the inner circumferential surface of the inner ring is provided with an internal spline structure for forming a spline connection with the drive shaft.

[0016] According to a second aspect of the present disclosure, the present disclosure provides a transmission including the torque limiter described in the first aspect.

[0017] The technical solutions provided by the embodiments of this disclosure can include the following beneficial effects: the axial preload of the elastic element controls the torque threshold transmitted between the inner and outer rings, while the axially movable inner ring contact plate realizes the overload protection function between the inner and outer rings. This effectively solves the technical problem that rigid gears in existing gearboxes or reduction gearboxes are prone to damage under overload conditions, and achieves a dynamic balance between torque transmission and overload protection. The structure is simple and requires no additional space or complex control devices. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0019] Figure 1 A cross-sectional view of a torque limiter provided for an exemplary embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the outer ring three-dimensional structure provided for an exemplary embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the three-dimensional structure of the inner ring contact plate provided for an exemplary embodiment of the present invention;

[0022] Figure 4 A three-dimensional structural diagram of an elastic element provided for an exemplary embodiment of the present invention. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0024] In this disclosure, unless otherwise stated, axial A, radial R, and circumferential W refer to the axial A, radial R, and circumferential W of the torque limiter 100, respectively; radially outer refers to the radially outer direction away from the torque limiter 100. Figure 1 The side of the central axis O in the diagram refers to the radially inner side, which is closer to the central axis O in the radial direction. Furthermore, "transmission connection" refers to the ability to transmit driving force / torque between two components, which can be directly connected or achieved through various transmission mechanisms or connection structures. The term "torsional connection" refers to a connection between two elements that does not rotate relative to each other, which can be achieved via a press fit (i.e., interference fit) or by integrally forming the two components. Those skilled in the art will understand the specific meaning of the above terms in this invention as appropriate.

[0025] To solve the above-mentioned technical problems, this disclosure provides a torque limiter 100, such as... Figure 1 As shown, the torque limiter 100 includes at least: an outer ring 10, an inner ring 20, a plurality of balls 30, and an elastic element 40.

[0026] Specifically, such as Figure 1 and Figure 2 As shown, an annular outer ring contact plate 11 is provided on the radially inner side of the outer ring 10, and the axial end face of the outer ring contact plate 11 (e.g.) Figure 1 The right side) is provided with a first groove 12 distributed circumferentially in the W direction. For example... Figure 1 and Figure 3 As shown, an inner ring contact plate 21 is provided radially outward from the inner ring 20, axially spaced from the outer ring contact plate 11. The axial end face of the inner ring contact plate 21 (e.g.) Figure 3 A second groove 22 corresponding to the first groove 12 is formed on the left side. A plurality of balls 30 are axially sandwiched between the first groove 12 and the second groove 22.

[0027] In this embodiment, both the first groove 12 and the second groove 22 adopt a periodic wave-shaped structure. That is, in the circumferential W direction, the peaks and troughs of multiple first grooves 12 (or second grooves 22) are alternately and continuously distributed, thereby forming a complete wave-shaped profile in the circumferential W direction. Under normal operating conditions, the ball bearing 30 is fitted between the corresponding troughs of the first groove 12 and the second groove 22 to achieve stable torque transmission. Preferably, in this embodiment, 16 first grooves 12 and 16 second grooves 22 are uniformly arranged in the circumferential W direction, ensuring the balance of torque transmission through symmetrical distribution.

[0028] In an optional embodiment, the plurality of first grooves 12 and / or second grooves 22 may also be arranged in a non-continuous interval, that is, a plurality of independent grooves are distributed at a preset interval in the circumferential W direction.

[0029] In another alternative, the outer ring contact plate 11 may remain in a flat plate form, with the second groove 22 provided only on the inner ring contact plate 21; or, the first groove 12 may be provided only on the axial end face of the outer ring contact plate 11, while the inner ring contact plate 21 adopts a flat plate structure.

[0030] Furthermore, such as Figure 1 and Figure 3 As shown, the outer ring contact plate 11 is fixedly connected to the outer ring 10. Preferably, the outer ring contact plate 11 is integrally formed on the radially inner side of the outer ring 10, that is, the axial position of the outer ring contact plate 11 remains unchanged. The inner ring contact plate 21 is connected to the inner ring 20 by means of axial movement to form a torque transmission connection. The elastic element 40 is located on the other axial end face of the inner ring contact plate 21 and axially presses the inner ring contact plate 21. Under normal working conditions, an axial pressing force is continuously applied to keep the inner ring contact plate 21 and the outer ring contact plate 11 in an axially clamped state on the ball 30.

[0031] By axially moving the inner ring contact plate 21, the ball 30 can be selectively clamped between the first groove 12 and the second groove 22, thereby enabling torque transmission between the inner ring contact plate 21 and the outer ring contact plate 11. When the transmitted torque is within the rated range, the ball 30 is stably engaged between the troughs of the first groove 12 and the second groove 22 to achieve torque transmission between the inner ring 20 and the outer ring 10.

[0032] The torque transmission path is blocked by controlling the contact state between the ball 30 and the first groove 12 and the second groove 22. When it is necessary to block the torque transmission, the ball 30 is in a state of disengagement or reduced contact force with at least one groove.

[0033] Specifically, when the transmitted torque exceeds the threshold, the second groove 22 of the inner ring contact plate 21 pushes the ball 30 to climb circumferentially. The ball 30 gradually contacts the crests of the first groove 12 and the second groove 22 and axially presses the inner ring contact plate 21, causing the inner ring contact plate 21 to overcome the axial preload of the elastic element 40 and move axially. The second groove 22 no longer presses the ball 30, causing the ball 30 to break free from the constraints of the first groove 12 and the second groove 22 and interrupt the torque transmission. Until the transmitted torque is restored to the rated range, the elastic element 40 resets the inner ring contact plate 21 and rebuilds the torque transmission path.

[0034] Therefore, it can be seen that the axial preload of the elastic element 40 controls the torque threshold between the inner ring 20 and the outer ring 10, while the axially movable inner ring contact plate 21 realizes the overload protection function between the inner ring 20 and the outer ring 10. This effectively solves the technical problem that rigid gears in existing gearboxes or reduction gearboxes are prone to damage under overload conditions, and achieves a dynamic balance between torque transmission and overload protection. The structure is simple and does not require additional space or complex control devices.

[0035] Furthermore, in some embodiments, the axial second end of the inner ring 20 (e.g. Figure 1 The right end shown has multiple radially protruding bosses 23 evenly distributed circumferentially, such as... Figure 3 As shown, the inner ring contact plate 21 has an axial groove 211 on its radially inner side, which corresponds to the number of bosses 23. The bosses 23 cooperate with the axial groove 211, so that the inner ring contact plate 21 can slide axially relative to the inner ring 20, while maintaining a reliable circumferential torque transmission connection with the inner ring 20, so that torque is transmitted between the inner ring 20 and the inner ring contact plate 21.

[0036] The boss 23 and the axial groove 211 are arranged with equal circumferential spacing to ensure that the force between the inner ring contact plate 21 and the inner ring 20 is evenly distributed, thereby improving the stability of torque transmission.

[0037] Furthermore, such as Figure 1 and Figure 3 As shown, the axial groove 211 does not penetrate the inner ring contact plate 21 axially. A limiting plate 212 is integrally formed at the end of the inner ring contact plate 21 near the ball 30, sealing the axial end of the axial groove 211 near the ball 30. When the inner ring contact plate 21 moves axially relative to the inner ring 20 to a preset position, the limiting surface of the limiting plate 212 abuts against the end face of the boss 23, preventing the axial displacement of the inner ring contact plate 21 from exceeding its travel, ensuring that the ball 30 remains within the clamping space formed by the first groove 12 and the second groove 22, and preventing the ball 30 from dislodging.

[0038] In an optional embodiment, an axial groove 211 may be provided on the outer peripheral surface of the inner ring 20, and a boss 23 may be provided on the radially inner side of the inner ring contact plate 21. Those skilled in the art can select an appropriate mating method according to actual assembly requirements, and such variations are all included within the protection scope of this disclosure.

[0039] Furthermore, in some embodiments, the axial first end of the inner ring 20 ( Figure 1 The left end (shown) is provided with an annular first baffle 24 extending radially outward, and the second axial end of the inner ring 20 is provided with a second baffle 25. The second baffle 25 is located axially outside the boss 23, and the elastic element 40 axially abuts against the boss 23 and the second baffle 25. The first baffle 24 and the second baffle 25 abut against the two axial ends of the outer ring 10 respectively to form an abutment fit, thereby limiting the axial position of the outer ring 10, effectively constraining the axial displacement of the outer ring 10 relative to the inner ring 20, and ensuring the stability of the relative positions of each component during torque transmission.

[0040] In some embodiments, the first baffle 24 is integrally formed with the inner ring 20, ensuring the overall strength of the inner ring 20 structure. Further, the second baffle 25 is a detachable independent component. Preferably, the second baffle 25 is a detachable clamping nut, and the axial second end of the inner ring 20 is provided with an external thread at the axial outer end of the boss 23. The clamping nut is threadedly connected to the axial second end of the inner ring 20 through the external thread. By making the second baffle 25 a detachable independent component, assembly and maintenance are facilitated.

[0041] In some embodiments, a first stepped shoulder 13 and a second stepped shoulder 14 are formed at both axial ends of the outer ring 10, respectively; the radial outer end of the first baffle 24 abuts against the first stepped shoulder 13, and the radial outer end of the second baffle 25 abuts against the second stepped shoulder 14.

[0042] By engaging with the first baffle 24 and the second baffle 25 respectively with the first stepped shoulder 13 and the second stepped shoulder 14, radial support can be formed on the outer ring 10 to limit the radial relative position between the outer ring 10 and the inner ring 20. At the same time, the engagement also limits the axial relative displacement between the outer ring 10 and the inner ring 20, preventing the outer ring 10 from moving axially relative to the inner ring 20. This ensures that the first groove 12 and the second groove 22 always form a stable axial clamp on the ball 30 under normal working conditions (i.e., when the transmitted torque is within the rated range), ensuring that the torque can be stably transmitted between the inner ring 20 and the outer ring 10.

[0043] Preferably, the axial outer end faces of the first baffle 24 and the second baffle 25 are coplanar with the corresponding axial end faces of the outer ring 10. This improves the appearance of the torque limiter 100, optimizes the axial spatial layout, and makes the overall structure more compact.

[0044] Furthermore, such as Figure 1 As shown, the axial end face of the outer ring contact plate 11 away from the first groove 12 forms an axial abutment fit with the first baffle 24 of the inner ring 20, thereby further optimizing the axial spatial layout and significantly improving the compactness of the overall structure.

[0045] In some embodiments, the elastic element 40 is an annular elastic element 40, which axially abuts against the second baffle 25 and the inner ring contact plate 21. By adjusting the depth of the external thread of the second baffle 25 screwed into the axial second end of the inner ring 20, the axial clamping force of the elastic element 40 can be adjusted, thereby adjusting the magnitude of the transmitted torque threshold.

[0046] In other embodiments, the selection of the elastic element 40 includes, but is not limited to, elastic energy storage elements such as torsion springs and helical springs. Its specific structural form can be adapted to meet the actual working conditions and should not be construed as a limitation on the scope of protection of this application.

[0047] In some embodiments, such as Figure 4 As shown, the elastic element 40 includes a first elastic element 41 and a second elastic element 42 arranged coaxially, wherein the outer diameter of the second elastic element 42 is smaller than the inner diameter of the first elastic element 41, and it is coaxially sleeved inside the first elastic element 41.

[0048] By setting two concentric elastic elements 40, assembly and positioning are not only facilitated, but the inner ring contact plate 21 can also obtain a uniformly distributed axial preload in the radial direction, preventing the inner ring contact plate 21 from tilting. In addition, the first elastic element 41 and the second elastic element 42 can also play a redundant role. When one elastic element 40 fails, the other elastic element 40 still maintains the necessary axial preload, ensuring that the ball 30 always remains in the first groove 12 and the second groove 22, and ensuring the reliability of torque transmission.

[0049] Preferably, the first elastic element 41 and the second elastic element 42 are configured with the same or different elastic coefficients to adapt to the axial preload requirements under different working conditions.

[0050] In some embodiments, the outer circumferential surface of the outer ring 10 is provided with a gear structure (not shown in the figure) for meshing with the gear system of the gearbox to form a meshing transmission; the inner circumferential surface of the inner ring 20 is provided with an internal spline structure (not shown in the figure) for forming a spline connection with the drive shaft.

[0051] The torque limiter 100 disclosed herein has the characteristics of bidirectional torque transmission and disconnection, that is, the outer ring 10 can transmit torque to the inner ring 20, or the inner ring 20 can transmit torque to the outer ring 10. In particular, through the coordinated cooperation of the inner ring contact plate 21, the outer ring contact plate 11, the ball 30 and the elastic element 40, the torque transmission path from the inner ring 20 to the outer ring 10, or the torque transmission path from the outer ring 10 to the inner ring 20, can be selectively blocked.

[0052] Based on the same inventive concept, this disclosure provides a gearbox including the torque limiter 100 described above. The specific manner in which the functions of the gearbox in the above embodiments are implemented has been described in detail in the embodiments relating to the torque limiter 100, and will not be elaborated upon here.

[0053] It is understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. The singular forms "a" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0054] It is further understood that the terms "first," "second," etc., are used to describe various structures, but these structures should not be limited to these terms. These terms are only used to distinguish structures of the same type from one another and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, a first structure can also be called a second structure, and similarly, a second structure can also be called a first structure.

[0055] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models 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 following claims.

[0056] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A torque limiter (100), characterized in that, include: The outer ring (10) has an annular outer ring contact plate (11) on its radially inner side, and the axial end face of the outer ring contact plate (11) has a first groove (12) distributed in the circumferential direction. The inner ring (20) has an inner ring contact plate (21) that is axially spaced from the outer ring contact plate (11) on its radially outer side. The inner ring contact plate (21) is axially movable and torque-transmittedly connected to the inner ring (20). The axial end face of the inner ring contact plate (21) has a second groove (22) corresponding to the first groove (12). Multiple balls (30) are sandwiched between the first groove (12) and the second groove (22); The elastic element (40) axially presses the inner ring contact plate (21) so that the inner ring contact plate (21) and the outer ring contact plate (11) axially clamp the ball (30); When the transmitted torque exceeds the threshold, the second groove (22) of the inner ring contact plate (21) pushes the ball (30) to climb, causing the inner ring contact plate (21) to move axially against the preload of the elastic element (40), resulting in the ball (30) disengaging from the constraints of the first groove (12) and the second groove (22) and interrupting the torque transmission; when the torque is restored, the elastic element (40) resets the inner ring contact plate (21) and rebuilds the torque transmission path.

2. The torque limiter (100) according to claim 1, characterized in that, The inner ring (20) has a first baffle (24) extending radially outward at its first axial end and a second baffle (25) at its second axial end. The first baffle (24) and the second baffle (25) abut against the two axial ends of the outer ring (10) respectively to limit the axial position of the outer ring (10).

3. The torque limiter (100) according to claim 2, characterized in that, The first baffle (24) is integrally formed with the inner ring (20), the second baffle (25) is a detachable clamping nut, the second end of the inner ring (20) is provided with an external thread, and the clamping nut is threadedly connected to the second end of the inner ring (20) through the external thread.

4. The torque limiter (100) according to claim 2, characterized in that, The outer ring (10) has a first stepped shoulder (13) and a second stepped shoulder (14) formed at both ends of its axial direction. The radial outer end of the first baffle (24) abuts against the first stepped shoulder (13), and the radial outer end of the second baffle (25) abuts against the second stepped shoulder (14); The axial outer surfaces of the first baffle (24) and the second baffle (25) are respectively coplanar with the axial end surfaces corresponding to the outer ring (10).

5. The torque limiter (100) according to claim 2, characterized in that, The outer ring contact plate (11) is integrally formed on the radial inner side of the outer ring (10), and the axial end face of the outer ring contact plate (11) away from the first groove (12) abuts against the first baffle (24) of the inner ring (20).

6. The torque limiter (100) according to claim 3, characterized in that, The inner ring (20) has a plurality of radially protruding bosses (23) evenly distributed circumferentially at its second axial end, and the bosses (23) are located at the inner axial end of the external thread. The inner ring contact plate (21) has an axial groove (211) on its radially inner side that corresponds to the number of the bosses (23). The boss (23) cooperates with the axial groove (211) so that the inner ring contact plate (21) can be axially slidably connected to the inner ring (20) for torque transmission.

7. The torque limiter (100) according to claim 2, characterized in that, The elastic element (40) is an annular elastic element (40), and the elastic element (40) abuts axially between the second baffle (25) and the inner ring contact plate (21).

8. The torque limiter (100) according to claim 7, characterized in that, The elastic element (40) includes a first elastic element (41) and a second elastic element (42) arranged coaxially. The outer diameter of the second elastic element (42) is smaller than the inner diameter of the first elastic element (41), and it is coaxially sleeved inside the first elastic element (41).

9. The torque limiter (100) according to claim 1, characterized in that, The outer circumferential surface of the outer ring (10) is provided with a gear structure for meshing with the gear system of the gearbox; The inner circumferential surface of the inner ring (20) is provided with an internal spline structure for forming a spline connection with the drive shaft.

10. A gearbox, characterized in that, Includes a torque limiter (100) as described in any one of claims 1-9.

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