Low-wear bicycle hub-ratchet structure and sliding sleeve transmission structure

Abstract

The application discloses a bicycle hub ratchet with reduced wear, and relates to the technical field of bicycle ratchets.The application solves the technical problems of the prior art, such as serious wear of a bicycle hub ratchet, short maintenance cycle, poor running lubricity and incapability of being compatible with high-viscosity lubricating grease.The application comprises a tower base, a shell, a sliding sleeve and a driving ratchet and a driven ratchet which are cooperated with each other.At least one of the meshing end faces of the driving ratchet and the driven ratchet is provided with four-section segmented ratchets, the segmented ratchets comprise a first guide-in segment, a second transition segment, a third meshing load-bearing segment and a fourth stop-limiting segment, the meshing impact is reduced through a low-inclination slope, the transmission cooperation of the sliding sleeve and the ratchet, oil guiding circulation and a conical centering structure are matched, the wear of the ratchet tooth surface and the transmission position is effectively reduced, the smoothness of the device is improved, and the maintenance cycle and the service life are prolonged.The application is suitable for a one-way transmission mechanism of a bicycle rear wheel hub and is suitable for use of high-viscosity lubricating grease.

Description

Technical Field

[0001] This invention relates to the field of bicycle ratchet technology, specifically to a low-wear bicycle hub ratchet structure and a sliding sleeve transmission structure, and also covers a sliding sleeve transmission structure that can be universally adapted to various unidirectional ratchets. Background Technology

[0002] Existing bicycle hub ratchet generally uses a single-sloping or two-stage ratchet structure. When gliding, the ratchet teeth have a long impact stroke and a large impact force, and the tooth surface is prone to continuous friction and wear. Additional operating resistance is generated between the ratchet teeth when gliding, resulting in poor overall smoothness and a poor riding experience. Such conventional structures mostly use low-viscosity lubricating grease, which is more prone to evaporation, loss, drying and failure compared to high-viscosity grease. The lubrication and protection effect is weak, and the buffering capacity against ratchet impact is insufficient. This leads to short maintenance cycles for parts, and after long-term use, problems such as abnormal noise, jamming, and tooth surface wear failure are likely to occur. It cannot meet the usage requirements of high durability, high smoothness and long maintenance cycle. Meanwhile, the existing auxiliary transmission structures of one-way ratchet are mostly proprietary designs that are bound to specific ratchet structures and specific limiting parts. They cannot be universally adapted to different types of one-way ratchet and different limiting implementation methods, resulting in poor adaptability and limited application scenarios. Summary of the Invention

[0003] This invention aims to solve the technical defects of existing bicycle hub ratchet, such as rapid wear, high sliding resistance, and poor sliding smoothness. It addresses the problem of obvious ratchet impact and jerking during sliding of conventional ratchet, and improves the shortcomings of traditional structure where grease tends to accumulate at the edges and corners and is difficult to circulate and lubricate effectively. This structure achieves limited grease circulation through its oil-guiding design, making it compatible with high-viscosity lubricating greases and thus significantly extending the maintenance cycle. It provides a hub ratchet structure that is structurally stable, has lower wear, smoother gliding, and longer maintenance cycles. Meanwhile, this invention provides a universal ratchet sliding sleeve transmission structure that can be adapted to various one-way ratchet mechanisms and various axial limiting methods, without needing to be bound to specific ratchet structures or specific parts, thus solving the problems of poor adaptability and limited application scenarios of existing transmission structures.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a four-segment unidirectional transmission ratchet structure, comprising a ratchet component, wherein the meshing surface of the ratchet component is provided with unidirectional transmission ratchet teeth, characterized in that the ratchet teeth are a four-segment independent functional segment structure connected sequentially along the transmission direction, comprising in sequence: a first guide segment for guiding, a second transition segment for smooth force transition, a third meshing bearing segment for bearing torque, and a fourth stop limiting segment for stopping and preventing disengagement; The angle B between the meshing guide surface of the first inlet segment and the radial reference plane passing through the ratchet center axis satisfies 0° < B < 20°, and the angle C between the meshing guide surface of the third meshing bearing segment and the radial reference plane passing through the ratchet center axis satisfies 0° < C < 20°. The angle D between the stop surface of the fourth stop limiting segment and the radial reference plane passing through the central axis of the ratchet satisfies 70°≤D<90°; Multiple ratchet teeth are arranged circumferentially on the meshing end face or radial meshing face of the ratchet component.

[0005] A ratchet sliding sleeve transmission structure includes a sliding sleeve body sleeved on the outside of a rotational central shaft. The sliding sleeve body cooperates with a one-way ratchet component to achieve transmission. The characteristic is that the axial displacement of the sliding sleeve body is constrained by a cooperating axial limiting structure, and it can only rotate freely around the axis of the rotational central shaft in the circumferential direction. A circumferential limiting transmission structure is provided between the sliding sleeve body and the mating one-way ratchet component. This circumferential limiting transmission structure restricts the relative circumferential rotation of the two components, while allowing them to slide relative to each other axially along the axis of the rotation center.

[0006] During operation, in the sliding state, the high-viscosity grease between the sliding sleeve body and the ratchet on one side generates viscous resistance, creating a circumferential speed difference between the two. This speed difference is converted into axial thrust through the circumferential limiting transmission structure, pushing the ratchet on the other side away axially and reducing the contact pressure between the ratchet meshing surfaces. In the driving state, the axial force is in the opposite direction, pushing the ratchet on the other side back into engagement.

[0007] A one-way meshing ratchet hub structure includes a central shaft, a driving ratchet and a driven ratchet that cooperate to achieve one-way transmission, characterized in that it also includes a sliding sleeve; The sliding sleeve is fitted on the outside of the central shaft, and the axial displacement of the sliding sleeve is constrained by the axial limiting structure. The active ratchet and the driven ratchet can move relative to each other along the central axis to achieve meshing transmission or separation slippage, and at least one of their meshing surfaces is provided with the aforementioned four-segment unidirectional transmission ratchet structure. The sliding sleeve adopts the ratchet sliding sleeve transmission structure described above, and is connected in conjunction with the driving ratchet or the driven ratchet.

[0008] Furthermore, the ratchet teeth of the ratchet are a segmented structure arranged along the meshing transmission direction. A radial reference plane is defined with the ratchet centerline as the reference. The transmission stop surface of the limiting segment is set almost vertically, and the included angle of the meshing bearing working surface is greater than the included angle of the working surface of the guide segment and the limiting segment. There is a small fit clearance between the sliding sleeve body and the surrounding mating parts, and there is a lubricating grease clearance in the ratchet mating part. The fit forms a sliding fit and lubrication arrangement structure. The ratchet mating part is also equipped with an oil guide structure to realize limited circulation of lubricating grease. Beneficial effects

[0009] This invention achieves its core technological advantages through the coordinated operation of a segmented ratchet and a sliding sleeve transmission structure. Together, they enhance the overall performance of the hub ratchet. The specific beneficial effects and corresponding technical features are as follows: 1. Reduce tooth surface wear and minimize meshing impact: The above-mentioned four-segment unidirectional transmission ratchet structure effectively shortens the impact stroke of the ratchet during sliding through the low-angle first introductory segment, reducing the collision impact and frictional wear between the ratchet teeth. From the tooth profile design level, it reduces tooth surface wear and reduces the fundamental source of sliding jerking. In the preferred scheme, the included angles B and C are controlled within the range of 0°~10°. In the optimal scheme, the angular deviation between the first introductory segment and the third meshing load-bearing segment does not exceed ±0.5°, which can achieve complete surface contact and further minimize sliding resistance and wear. At the same time, the fourth stop limiting segment with 70°≤D<90° ensures stable load bearing of the driving torque and eliminates the risk of slippage and disengagement.

[0010] 2. Improved gliding smoothness and reduced gliding resistance: The above-mentioned ratchet sleeve transmission structure can create a speed difference with the surrounding structure due to the viscous resistance of the lubricating grease during the gliding stage. This speed difference is converted into axial separation force through structural cooperation. When an elastic reset element is set, this axial force can overcome part of the preload pressure of the elastic reset element, or even completely offset the preload force, pushing the two ratchets to separate axially, greatly reducing the contact pressure of the ratchet meshing surface, fundamentally weakening the gliding jerking feeling, significantly reducing gliding resistance and improving the gliding smoothness of the wheel set.

[0011] 3. Improved power response speed and further reduced wear: During the transition from coasting to drive, the sliding sleeve transmission structure also generates a speed difference due to the viscous resistance of the grease, producing an axial force that prompts the ratchet to engage. If equipped with an elastic reset element, this engagement force can be superimposed with the preload reset force to jointly drive the ratchet to engage quickly, significantly improving the power response speed of the hub. At the same time, due to the significant reduction in engagement force and impact force, tooth surface wear is further reduced, which can greatly reduce the generation of metal powder caused by wear and prevent the grease from being contaminated and deteriorated.

[0012] 4. Extend maintenance cycle and service life: With its oil-guiding structure and compatibility with high-viscosity greases, the lubrication condition remains stable over a long period of time, further improving the durability of the hub ratchet and significantly extending the maintenance cycle and overall service life. Attached Figure Description

[0013] Figure 1 This is an overall axial sectional assembly diagram of the one-way meshing ratchet hub structure described in this invention; Figure 2 This is a schematic diagram of the meshing and engagement of the four-segment unidirectional transmission ratchet structure described in this invention, and an enlarged cross-sectional schematic diagram of a single set of ratchet teeth; Figure 3 This is an exploded axial view of the ratchet sliding sleeve transmission structure described in this invention; The accompanying drawing is a simplified overall schematic diagram of the unidirectional meshing ratchet hub structure described in this invention.

[0014] In the figure: 1-housing, 2-central shaft, 3-elastic reset component, 4-driven ratchet, 5-driving ratchet, 6-base, 7-sliding sleeve, 501-third engagement bearing section, 502-second transition section, 503-first guide section, 504-fourth stop limiting section. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are used to clearly illustrate the core hub assembly technical solution of the present invention, rather than to limit the scope of protection of the present invention.

[0016] The low-wear bicycle hub ratchet of this embodiment includes a housing 1, a central shaft 2, an elastic reset member 3, a driven ratchet 4, a driving ratchet 5, a freehub base 6, and a sliding sleeve 7; The central shaft 2 passes through the central hole of the housing 1 and the tower base 6, and the tower base 6 and the housing 1 are rotatably connected by two sets of bearings; The driving ratchet 5 is connected to the base 6 via an internal spline circumferential transmission, and the driven ratchet 4 is connected to the housing 1 via an external spline circumferential transmission. The meshing end faces of the driving ratchet 5 and the driven ratchet 4 are provided with the above-mentioned four-segment unidirectional transmission ratchet structure. Among them, the included angle B of the first inlet section 503 is 8°, and the included angle C of the third meshing bearing section 501 is 8°. The angle deviation between the two is 0°, which meets the preferred range of 0°<B≤10° and 0°<C≤10°, as well as the optimal solution requirement of the absolute value of the angle deviation ≤0.5°, so as to achieve complete surface contact and reduce wear; the included angle D of the fourth stop limiting section 504 is 82°, which meets the design requirement of 70°≤D<90°, and there is no risk of slippage; The sliding sleeve 7 is the sliding sleeve body of the above-mentioned sliding sleeve transmission structure. It is sleeved on the outside of the central shaft 2. Its axial displacement is constrained by the axial limiting structure of the limiting step on the central shaft. The outer transmission teeth of the sliding sleeve 7 mesh with the inner transmission teeth of the driven ratchet 4. The tooth surface mating angle is 45°. The circumferential limiting transmission structure formed by the two is a precision spline sliding fit structure with a single-sided clearance ≤0.1mm. The single-sided clearance between the sliding sleeve 7 and the central shaft 2 is 0.05mm, and an annular closed oil guide groove is provided on the outer wall of the central shaft 2; The elastic reset element 3 is a wave spring, which is installed on the side of the driven ratchet 4 that is axially away from the driving ratchet 5, to provide axial preload reset force; High-viscosity damping grease is filled between the circumferential rotating mating surfaces of the sliding sleeve 7 and the central shaft 2.

[0017] The working principle of this embodiment: In the gliding state, the base 6 and the driving ratchet 5 stop rotating, while the housing 1 drives the driven ratchet 4 to rotate continuously. The high-viscosity damping grease between the sliding sleeve 7 and the axial limiting structure generates viscous resistance, which creates a circumferential speed difference between the sliding sleeve 7 and the driven ratchet 4. This speed difference is converted into an axial separation force through the meshing tooth surface, pushing the driven ratchet 4 axially away from the driving ratchet 5, greatly reducing the contact pressure between the meshing surfaces of the two. There is only slight contact between the ratchet teeth, without severe impact and friction, significantly reducing the gliding resistance and greatly improving the smoothness. When switching to drive mode, the base 6 drives the active ratchet 5 to rotate. Due to the viscous resistance, the sliding sleeve 7 forms a circumferential speed difference with the active ratchet 5, which is converted into axial meshing force. Combined with the preload of the elastic reset member 3, it pushes the active ratchet 5 to quickly mesh with the driven ratchet 4. The power response is rapid, the meshing impact is small, and the tooth surface wear is greatly reduced.

[0018] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A four-stage one-way drive ratchet structure comprising a ratchet member, the engaging surface of the ratchet member being provided with one-way drive ratchets, characterized in that, The ratchet is a four-segment independent functional segment structure connected sequentially along the transmission direction, including: a first guide segment (503) for guiding, a second transition segment (502) for smooth force transition, a third engagement bearing segment (501) for bearing torque, and a fourth stop limiting segment (504) for stopping and preventing disengagement. The angle B between the meshing guide surface of the first inlet segment (503) and the radial reference plane passing through the ratchet center axis satisfies 0° < B < 20°, and the angle C between the meshing guide surface of the third meshing bearing segment (501) and the radial reference plane passing through the ratchet center axis satisfies 0° < C < 20°. The angle D between the stop surface of the fourth stop limiting segment (504) and the radial reference plane passing through the ratchet center axis satisfies 70°≤D<90°; Multiple ratchet teeth are arranged circumferentially on the meshing end face or radial meshing face of the ratchet component.

2. The four-segment unidirectional transmission ratchet structure according to claim 1, characterized in that, The values ​​of the included angles B and C satisfy 0°<B≤10° and 0°<C≤10°.

3. The four-segment unidirectional transmission ratchet structure according to claim 1, characterized in that, The absolute value of the numerical deviation between the included angle B and the included angle C is ≤0.5°.

4. The four-segment unidirectional transmission ratchet structure according to claim 1, characterized in that, The ratchet teeth are arranged circumferentially, and the circumferential spacing between adjacent ratchet teeth is set according to the load-bearing requirements.

5. The four-segment unidirectional transmission ratchet structure according to claim 1, characterized in that, The four-segment functional surfaces of the ratchet are integrally formed using continuous spline curves, circular arc surfaces, or gradually changing inclined surfaces, without clearly defined segmented steps.

6. A ratchet sliding sleeve transmission structure, comprising a sliding sleeve body sleeved on the outside of a rotational central shaft, wherein the sliding sleeve body cooperates with a one-way ratchet component to achieve transmission, characterized in that, The axial displacement of the sliding sleeve body is constrained by the axial limiting structure, and it can only rotate freely around the axis of the rotation center. A circumferential limiting transmission structure is provided between the sliding sleeve body and the mating one-way ratchet component. This circumferential limiting transmission structure restricts the relative circumferential rotation of the two components, while allowing them to slide relative to each other axially along the axis of the rotation center.

7. The ratchet sliding sleeve transmission structure according to claim 6, characterized in that, The circumferential limiting transmission structure includes an outer transmission tooth on the outer wall of the sliding sleeve body and an inner transmission tooth on the inner wall of the matching one-way ratchet component, wherein the outer transmission tooth and the inner transmission tooth mesh with each other. The included angle of the tooth surface of the outer transmission tooth of the sliding sleeve body is between the angle of the ratchet tooth cutting surface and the angle of the ratchet tooth stop surface of the mating one-way ratchet component.

8. The ratchet sliding sleeve transmission structure according to claim 7, characterized in that, The included angle of the tooth surface of the outer transmission tooth of the sliding sleeve body is the midpoint angle between the angle of the ratchet tooth cutting surface and the angle of the ratchet tooth stop surface of the mating one-way ratchet component.

9. The ratchet sliding sleeve transmission structure according to claim 6, characterized in that, The circumferential limiting transmission structure is a precision spline sliding fit structure with a single-sided clearance ≤0.1mm.

10. A one-way meshing ratchet hub structure, comprising a central shaft (2), a driving ratchet (5) and a driven ratchet (4) that cooperate to achieve one-way transmission, characterized in that, It also includes the sliding sleeve (7); The sliding sleeve (7) is sleeved on the outside of the central shaft (2), and the axial displacement of the sliding sleeve (7) is constrained by the axial limiting structure. The active ratchet (5) and the driven ratchet (4) can move relative to each other along the central axis (2) to achieve meshing transmission or separation slippage, and at least one of their meshing surfaces is provided with the four-segment unidirectional transmission ratchet structure as described in claim 1. The sliding sleeve (7) adopts the ratchet sliding sleeve transmission structure as described in claim 6, and is connected in cooperation with the driving ratchet (5) or the driven ratchet (4).

11. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, The meshing end faces of the active ratchet (5) and the driven ratchet (4) are matching conical mating surfaces, and the four-segment unidirectional transmission ratchet structure is correspondingly set on the conical mating surface.

12. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, The central shaft (2), the driving ratchet (5), the driven ratchet (4), and any one or more components of the axial limiting structure are provided with oil guide grooves or oil guide holes for the circulation of lubricating grease.

13. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, The single-sided fitting clearance between the sliding sleeve (7) and its circumferentially rotating and axially limiting fitting parts is 0.03mm to 0.50mm. A micro-fitting clearance of 0.01mm to 0.05mm is provided between the meshing end faces of the driving ratchet (5) and the driven ratchet (4) formed by machining precision.

14. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, At least one of the driving ratchet (5) and the driven ratchet (4) is provided with an elastic reset member (3).

15. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, The circumferential rotational mating surface between the sliding sleeve (7) and the central shaft (2) or the axial limiting structure is filled with high-viscosity damping grease.

16. The unidirectional meshing ratchet hub structure according to claim 10, characterized in that, It also includes the tower base (6) and the shell (1); The tower base (6) is circumferentially connected to the active ratchet (5) or the driven ratchet (4), and the housing (1) is correspondingly circumferentially connected to the driven ratchet (4) or the active ratchet (5).

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