Torque limiter and gearbox

Abstract

The present disclosure relates to a torque limiter and a gearbox. The torque limiter comprises: an outer ring; an inner ring coaxially arranged in the outer ring and having a non-circular outer periphery; a torque limiting assembly comprising: two first limiting blocks fixed to the inner periphery of the outer ring and forming a pair of parallel limiting planes; two spaced contact members, the two ends of the contact members abutting against the limiting planes and being capable of sliding relative to the limiting planes, and the inner side wall of the contact members abutting against the outer periphery of the inner ring; and two elastic return members connected to the two contact members for providing elastic pre-tightening force of the contact members pressing against the outer periphery of the inner ring; wherein when the torque borne by the inner ring is less than a preset threshold, the non-circular hub of the inner ring drives the contact members to rotate and drive the first limiting blocks to transmit the torque to the outer ring; when the torque of the inner ring is greater than the preset threshold, the non-circular profile of the inner ring drives the contact members to overcome the elastic force of the elastic return members to displace radially, so that the inner ring and the torque limiting assembly produce relative rotational slip.

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 / 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; an inner ring coaxially disposed within the outer ring and having a non-circular outer circumferential surface; a torque limiting assembly, comprising: two first limiting blocks fixed to the inner circumferential surface of the outer ring and forming a pair of parallel limiting planes; two spaced-apart contact members, the two ends of the contact members abutting against the limiting planes and being slidable relative to the limiting planes, and the inner sidewalls of the contact members abutting against the outer circumferential surface of the inner ring; and two elastic reset members connecting the two contact members for providing an elastic preload force for the contact members to press against the outer circumferential surface of the inner ring; wherein, when the torque borne by the inner ring is less than a preset threshold, the non-circular hub of the inner ring drives the contact members to rotate and drives the first limiting blocks to transmit the torque to the outer ring; when the torque of the inner ring is greater than the preset threshold, the non-circular contour of the inner ring drives the contact members to overcome the elastic force of the elastic reset members and radially displace, causing the inner ring and the torque limiting assembly to rotate and slip relative to each other.

[0008] In some embodiments, the contact member is a flat plate structure, and the two ends of the contact member form a right-angle sliding pair with the limiting plane.

[0009] In some embodiments, the first limiting block is an arc-shaped limiting block, the radial outer side of the first limiting block is in contact with the inner circumferential surface of the outer ring, and the radial inner side of the first limiting block forms the opposing limiting plane.

[0010] In some embodiments, the first limiting block is integrally formed with the outer ring.

[0011] In some embodiments, side plates are provided on both axial sides of the outer ring, and limiting steps are formed on the corresponding axial sides of the inner ring. The side plates abut against the limiting steps to restrict the axial movement of the inner ring relative to the outer ring.

[0012] In some embodiments, the elastic reset member is a helical spring and is connected to both ends of the contact member. The distance between the two helical springs is greater than the maximum radial dimension of the outer circumference of the inner ring, so as to avoid interference with the helical spring when the inner ring rotates relative to the contact member.

[0013] In some embodiments, the outer periphery of the inner ring has an elliptical outline and forms two symmetrically arranged arc-shaped protrusions.

[0014] In some embodiments, the outer circumferential surface of the outer ring is provided with a gear structure, and the inner circumferential surface of the inner ring is provided with a spline structure.

[0015] According to a second aspect of the present disclosure, the present disclosure provides a transmission including a torque limiter as described in the first aspect.

[0016] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: the torque limiting component between the inner and outer rings 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 torque limiting component has a simple structure and does not require additional space or complex control devices. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic cross-sectional view of a torque limiter transmitting torque according to an exemplary embodiment;

[0019] Figure 2 This is a longitudinal cross-sectional schematic diagram of a torque limiter transmitting torque according to an exemplary embodiment;

[0020] Figure 3 This is a schematic cross-sectional view of a torque limiter slipping according to an exemplary embodiment;

[0021] Figure 4 This is a schematic longitudinal section diagram of a torque limiter slipping according to an exemplary embodiment;

[0022] Figure 5 This is a longitudinal cross-sectional schematic diagram of a torque limiter transmitting torque according to another exemplary embodiment. 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 2 and Figure 3The 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... Figures 1 to 4 As shown, the torque limiter 100 includes an outer ring 10, an inner ring 20, and a torque limiting component 30.

[0026] The inner ring 20 and the outer ring 10 are coaxially arranged, with the inner ring 20 coaxially located within the outer ring 10. Specifically, in this embodiment, the torque limiter 100 is preferably applied to a transmission system within a gearbox or reduction gearbox. In this application scenario, after receiving torque input from the inner ring 20, the outer ring 10 of the torque limiter 100 needs to further transmit the torque outward. For this purpose, the outer circumferential surface of the outer ring 10 is preferably circular, and the outer circumferential surface of the outer ring 10 is preferably provided with a gear structure, including but not limited to spur gears, helical gears, or herringbone gears, to improve the efficiency of torque transmission and reduce transmission noise.

[0027] It should be understood that, in other alternative embodiments, the outer peripheral surface contour of the outer ring 10 may be adaptively adjusted according to actual assembly requirements or functional requirements, including but not limited to adopting a square, elliptical or other geometric shape, so that the torque limiter 100 can better adapt to different transmission system layouts and installation conditions, and this disclosure does not specifically limit it in this regard.

[0028] The inner circumferential surface of the inner ring 20 is provided with a spline tooth structure (not shown in the figure), which is configured to mesh with the external spline of the drive shaft (not shown in the figure). Through the spline meshing engagement, the inner ring 20 can receive the input torque transmitted from the drive shaft. The tooth profile parameters of the spline tooth structure of the inner ring 20 (including but not limited to the number of teeth, module, pressure angle, etc.) can be set according to actual transmission requirements to ensure the stability of torque transmission and ease of assembly.

[0029] It should be noted that in other embodiments, the torque transmission connection between the inner ring 20 and the drive shaft may also adopt a keyway fit, a polygonal fit, or other circumferential fixing structure. These alternative solutions are all within the protection scope of this disclosure.

[0030] The torque limiting component 30 is disposed radially R between the inner ring 20 and the outer ring 10. For example... Figure 1 and Figure 3 As shown, the torque limiting component 30 includes a first limiting block 31, a contact element 32, and an elastic reset element 33. The inner ring 20 can transmit torque to the outer ring 10 through the torque limiting component 30. When the torque received by the inner ring 20 exceeds a preset threshold, the inner ring 20 can slip relative to the outer ring 10 through the torque limiting component 30, thereby limiting the transmission of torque to the outer ring 10. The torque limiter 100 of this disclosure, through its simple structure, ensures reliable torque transmission under normal operating conditions while also providing overload protection.

[0031] Specifically, at least two first limiting blocks 31 are provided, and they are arranged along the first direction (e.g., Figure 1 and Figure 3 The first limiting block 31 is fixedly connected to the inner circumferential surface of the outer ring 10, so that the first limiting block 31 and the inner circumferential surface of the outer ring 10 form an anti-torsional connection. A limiting plane 311 is provided on the radial inner side of each first limiting block 31, and the limiting planes 311 of the two first limiting blocks 31 are arranged parallel to each other.

[0032] Two contacts 32 are provided, and they are arranged along the second direction (e.g., Figure 1 and Figure 3 The two contact members 32 are arranged at intervals in the vertical direction shown, wherein the second direction is perpendicular to the first direction. The two ends of the contact member 32 are respectively in non-interference contact with the limiting plane 311 of the first limiting block 31 on both sides, so that the contact member 32 can slide freely relative to the limiting plane 311 of the first limiting block 31 along the second direction, thereby adjusting the interval between the two contact members 32, but the contact member 32 cannot rotate relative to the first limiting block 31, and the contact member 32 can transmit torque to the first limiting block 31.

[0033] The two contact members 32 and the two first limiting blocks 31 together form a space that can accommodate the inner ring 20, which is then accommodated within the space enclosed by the two first limiting blocks 31 and the two contact members 32. An elastic reset member 33 is elastically connected between the two contact members 32 along the second direction to apply an elastic preload to the contact members 32, so that the inner sidewall of the contact member 32 can always maintain contact with the outer peripheral surface of the inner ring 20.

[0034] like Figure 1 and Figure 3 As shown, the outer periphery of the inner ring 20 has a non-circular outline.

[0035] Specifically, the torque transmitted from the drive shaft to the inner ring 20 causes the inner ring 20 to tend to rotate; under the preload of the elastic reset member 33, the inner sidewall of the contact member 32 forms a circumferential resistance torque on the non-circular contour of the outer circumference of the inner ring 20. When the torque borne by the inner ring 20 is less than a preset threshold, such as Figure 1 and Figure 2 As shown, the non-circular contour of the outer circumference of the inner ring 20 drives the contact member 32 to rotate. The contact member 32 abuts against the limiting plane 311 of the first limiting block 31 at both ends, thereby transmitting the torque sequentially to the outer ring 10 through the first limiting block 31, achieving stable torque transmission.

[0036] When the torque borne by the inner ring 20 exceeds the preset threshold, such as Figure 3 and Figure 4 As shown, the non-circular contour of the outer circumference of the inner ring 20 forces the contact 32 to move radially outward to overcome the elastic force applied by the elastic reset member 33. During this process, the contact 32 slides radially outward along the limiting plane 311 of the first limiting block 31, increasing the gap between the two contact members 32, ultimately causing relative rotational slippage between the inner ring 20 and the inner sidewall of the contact 32. This slippage effectively interrupts torque transmission, thereby preventing damage to the transmission system due to overload.

[0037] It should be noted that the preset threshold is the circumferential resistance torque from the contact member 32 that the non-circular contour of the outer circumference of the inner ring 20 withstands when it overcomes the preload of the elastic reset member 33. The preload of the elastic reset member 33 can be adjusted according to different preset thresholds to ensure that the torque limiting component 30 reliably transmits torque under rated operating conditions and triggers the slippage protection function in a timely manner when overloaded.

[0038] In this embodiment, the contact member 32 has a flat plate structure. This flat plate structure allows the two ends of the contact member 32 to make perpendicular contact with the limiting plane 311, forming a right-angle sliding pair. When the torque on the inner ring 20 does not exceed a preset threshold, the rigid contact of the right-angle sliding pair can transmit the torque from the inner ring 20 to the first limiting block 31 through the contact member 32. When the torque on the inner ring 20 exceeds the preset threshold, the right-angle sliding pair allows the contact member 32 to slide along the limiting plane 311, resulting in relative slippage between the outer surface of the inner ring 20 and the inner sidewall of the contact member 32, thus achieving torque limiting protection between the inner ring 20 and the outer ring 10.

[0039] After slippage occurs between the inner ring 20 and the contact element 32, the two contact elements 32 reset under the preload of the elastic reset element 33. Compared to friction disc clutches, traditional friction discs rely on axial pressure to adjust the torque threshold, while this solution achieves this through radial elastic preload of the elastic reset element 33, resulting in a simpler structure.

[0040] In this embodiment, the outer periphery of the inner ring 20 has an elliptical outline and forms two symmetrically arranged arc-shaped protrusions 22. During the slippage of the inner ring 20 relative to the inner surface of the contact member 32, the curvature of the arc-shaped protrusions 22 can guide the contact member 32 to smoothly move radially, reducing the impact vibration and wear between the outer periphery of the inner ring 20 and the inner surface of the contact member 32.

[0041] The torque limiting component 30 employs a structure in which a flat contact 32 engages with a symmetrically arranged arc-shaped protrusion 22 circumferentially positioned on the inner ring 20. The geometric symmetry of the arc-shaped protrusion 22 ensures that the torque threshold remains consistent during forward and reverse torque transmission, allowing the torque limiting component 30 to transmit torque bidirectionally. Furthermore, when the transmitted torque exceeds a preset threshold, the flat contact 32 and the arc-shaped protrusion 22 can slide bidirectionally against each other, achieving a bidirectional torque limiting function. Compared to a one-way clutch in transmission, this structure is simple and requires no additional direction recognition mechanism. Forward can be defined as the direction in which the inner ring 20 transmits torque to the outer ring 10, and reverse can be defined as the direction in which the outer ring 10 transmits torque to the inner ring 20.

[0042] In other embodiments, the structure of the contact element 32 and the protrusion 22 on the outer peripheral surface of the inner ring 20 can be adapted to meet the actual application requirements. Specifically, the contact element 32 can adopt a modified structure such as a wave plate or an inverted V-shaped plate, and correspondingly, the protrusion 22 can be wedge-shaped or other geometric shapes to meet the requirements of different torque transmission directions, bidirectional transmission, and specific slippage directions. Those skilled in the art should understand that the above-mentioned structural modifications are all within the protection scope of this disclosure.

[0043] In some embodiments, the first limiting block 31 may be a plate-like structure. In this embodiment, such as... Figure 1 and Figure 3 As shown, the first limiting block 31 is an arc-shaped limiting block. The radially outer contour of the first limiting block 31 is closely fitted with the inner circumferential surface of the outer ring 10, and the radially inner side of the first limiting block 31 forms a relatively parallel limiting plane 311. Compared with the plate-shaped first limiting block 31, the arc-shaped limiting block, through its unique curved surface fit, can achieve a more stable connection and fit with the outer ring 10, thereby improving the stability of the overall structure and the reliability of torque transmission.

[0044] In some embodiments, the connection method between the first limiting block 31 and the outer ring 10 needs to be selected comprehensively based on functional requirements, process costs, and usage environment. The connection methods between the first limiting block 31 and the outer ring 10 include, but are not limited to, integral molding, bonding, welding, and bolt connection. The specific implementation method can be adjusted according to actual working conditions.

[0045] In this embodiment, the first limiting block 31 and the outer ring 10 can be integrally formed. This integrally formed structure eliminates any connection gaps between them, avoiding stress concentration caused by welding or bolting, and resulting in stronger overall fatigue resistance. When the contact element 32 rigidly abuts against the limiting plane 311 of the first limiting block 31 to transmit torque, the integrally formed structure ensures a more uniform load distribution on the outer ring 10, which has the first limiting block 31. Furthermore, the integrally formed structure eliminates the need for connecting parts such as bolts and pins, resulting in fewer parts, fewer production processes, and lower management costs.

[0046] In other alternative embodiments, such as Figure 5 As shown, the first limiting block 31 can be set to four blocks, corresponding to the four ends of the two contact members 32 respectively. By discretizing the arrangement of the first limiting block 31, the redundant material of the overall torque limiter is reduced, and the total mass of the torque limiter 100 is reduced.

[0047] In the embodiments disclosed herein, such as Figure 2 and Figure 4 As shown, side plates 11 are respectively provided on both axial sides of the outer ring 10, and limiting steps 21 are formed on the corresponding axial sides of the inner ring 20. The radially outer end of the side plate 11 is torsionally connected to the outer ring 10, and the radially inner end of the side plate 11 can abut against the limiting steps 21 with clearance fit to limit the axial movement of the inner ring 20 relative to the outer ring 10, while ensuring that the inner ring 20 is not interfered with by the side plate 11 when it rotates.

[0048] The side plate 11 can be a structure independent of the outer ring 10 and the inner ring 20. During assembly, one side plate 11 can be fixed to the outer ring 10 first, then the torque limiting component 30 and the inner ring 20 can be installed, and finally the other side plate 11 can be fixed. The split side plate 11 also facilitates the assembly and maintenance of the torque limiter 100.

[0049] The side plate 11, outer ring 10, and inner ring 20 together form a relatively sealed space, which can effectively prevent the entry of external dust or sewage. This prevents contaminants from interfering with the sliding of the contact 32 on the limiting plane 311, and prevents corrosive liquids and gases such as sewage from damaging the elastic reset member 33, thus avoiding the failure of the torque limiting function and improving the working stability of the torque limiter 100 device in harsh environments.

[0050] In this embodiment, the elastic reset member 33 adopts a helical spring structure. Two elastic reset members 33 can be provided and symmetrically arranged at both ends of the contact member 32. The distance between the two helical springs is greater than the maximum radial dimension of the outer circumference of the inner ring 20, thereby ensuring that the inner ring 20 will not interfere with the helical spring when rotating relative to the contact member 32.

[0051] In other alternative embodiments, the resilient reset member 33 may also employ a connection structure such as an elastic band, elastic rope, or elastic chain. These alternatives can also achieve the pre-tightening function and the resilient reset function of the contact member 32.

[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: Outer ring (10); The inner ring (20) is coaxially disposed within the outer ring (10) and its outer circumferential surface has a non-circular outline; Torque limiting assembly (30), comprising: Two first limiting blocks (31) are fixed to the inner circumferential surface of the outer ring (10) and form a pair of parallel limiting planes (311); Two spaced-apart contact members (32), the two ends of which abut against the limiting plane (311) and are slidable relative to the limiting plane (311), and the inner sidewall of the contact member (32) abuts against the outer peripheral surface of the inner ring (20); and Two elastic reset members (33) are connected to two contact members (32) for providing elastic preload force for the contact members (32) to press against the outer circumferential surface of the inner ring (20); When the torque borne by the inner ring (20) is less than a preset threshold, the non-circular hub of the inner ring (20) drives the contact member (32) to rotate and drive the first limiting block (31) to transmit the torque to the outer ring (10); when the torque of the inner ring (20) is greater than the preset threshold, the non-circular contour of the inner ring (20) drives the contact member (32) to overcome the elastic force radial displacement of the elastic reset member (33), so that the inner ring (20) and the torque limiting component (30) rotate and slip relative to each other.

2. The torque limiter (100) according to claim 1, characterized in that, The contact element (32) has a flat plate structure, and the two ends of the contact element (32) form a right-angle sliding pair with the limiting plane (311).

3. The torque limiter (100) according to claim 1, characterized in that, The first limiting block (31) is an arc-shaped limiting block. The radial outer side of the first limiting block (31) is in contact with the inner circumferential surface of the outer ring (10), and the radial inner side of the first limiting block (31) forms the opposing limiting plane (311).

4. The torque limiter (100) according to claim 3, characterized in that, The first limiting block (31) is integrally formed with the outer ring (10).

5. The torque limiter (100) according to claim 1, characterized in that, Side plates (11) are provided on both sides of the outer ring (10) along the axial direction. Limiting steps (21) are formed on both sides of the inner ring (20) along the axial direction. The side plates (11) abut against the limiting steps (21) to limit the axial movement of the inner ring (20) relative to the outer ring (10).

6. The torque limiter (100) according to claim 1, characterized in that, The elastic reset member (33) is a helical spring and is connected to both ends of the contact member (32). The distance between the two helical springs is greater than the maximum radial dimension of the outer circumference of the inner ring (20) so as to avoid interference with the helical spring when the inner ring (20) rotates relative to the contact member (32).

7. The torque limiter (100) according to claim 1, characterized in that, The outer periphery of the inner ring (20) has an elliptical shape and forms two symmetrically arranged arc-shaped protrusions (22).

8. The torque limiter (100) according to claim 1, characterized in that, The outer ring (10) has a gear structure on its outer circumferential surface, and the inner ring (20) has a spline tooth structure on its inner circumferential surface.

9. A gearbox, characterized in that, Includes a torque limiter (100) as described in any one of claims 1-8.

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