Hub shaft lever limiting structure and hub

Abstract

The hub shaft lever limiting structure comprises a hub shell, a tower footing in transmission connection with the hub shell and a shaft lever penetrating through the hub shell and the center of the tower footing, a first bearing and a second bearing are arranged between the hub shell and the shaft lever, and a third bearing is arranged between the tower footing and the shaft lever. The third bearing is located on the side, away from the hub shell, in the tower footing. A sliding bearing is arranged between the second bearing and the third bearing, the sliding bearing is connected to the shaft rod in a sleeved mode, the outer wall of the sliding bearing abuts against the inner wall of the tower footing, and the end faces of the two sides of the sliding bearing abut against the end face of the inner ring of the second bearing and the end face of the inner ring of the third bearing respectively. An original shaft sleeve, an original intermediate gasket and an original rolling bearing are replaced, the structure is simplified, the assembly process is optimized, the number of parts is reduced, the assembly difficulty and the error rate are reduced, meanwhile, the overall weight is remarkably reduced, and the requirement of a high-performance bicycle for lightweight design is met.

Description

Technical Field

[0001] This utility model belongs to the field of hub technology and discloses a hub shaft limiting structure and a hub. Background Technology

[0002] As one of the core components of a bicycle wheel, the structural design of the hub has a crucial impact on the overall riding performance, weight control, and assembly efficiency. In existing technologies, a hub typically includes a hub shell, freehub body, axle, and multiple bearing structures. Among these, the axle, as the core component for transmitting loads and providing rotational support, needs to be supported by multiple rolling bearings within the hub shell and freehub body to ensure good rotational accuracy and resistance to lateral loads during use.

[0003] To achieve axial positioning and balanced load distribution, existing hub designs often incorporate multiple components inside the freehub base, such as bearings, bushings, and spacers. While these components work together to provide positioning and support, their complex structure, cumbersome assembly process, and stringent tolerance requirements make them prone to problems such as excessive axial clearance, increased rotational resistance, and abnormal noises if improperly installed, negatively impacting the overall user experience. Furthermore, the multi-bearing structure increases overall weight, hindering the lightweight design of high-performance bicycles.

[0004] Specifically:

[0005] 1. Precise adjustment of bushings and shims is required between bearings to ensure axial preload. The assembly process is complicated and requires high precision in the machining of parts.

[0006] 2. In traditional multi-bearing structures, improper control of the fit clearance during assembly may lead to increased rotational resistance.

[0007] 3. Under high-speed riding or heavy load conditions, uneven force distribution between the bearing gaskets and bushings may lead to localized stress concentration, affecting structural reliability. Utility Model Content

[0008] To address the aforementioned issues, this invention provides a hub axle limiting structure and a hub, which simplifies the structure and optimizes the assembly process, reduces the number of parts, lowers the assembly difficulty and error rate, and significantly reduces the overall weight, thus meeting the lightweight design requirements of high-performance bicycles.

[0009] The technical solution provided by this utility model is as follows:

[0010] On one hand, a hub axle limiting structure includes a hub shell, a freehub base that is connected to the hub shell in a transmission, and a shaft that passes through the center of the hub shell and the freehub base. A first bearing and a second bearing are provided between the hub shell and the shaft, and a third bearing is provided between the freehub base and the shaft. The third bearing is located inside the freehub base on the side away from the hub shell.

[0011] A sliding bearing is provided between the second and third bearings. The sliding bearing is sleeved on the shaft, and its outer wall abuts against the inner wall of the tower base. The two end faces of the sliding bearing abut against the inner ring end faces of the second and third bearings, respectively.

[0012] In some implementations, the sliding bearing is a polymer sliding bearing.

[0013] In some implementations, the sliding bearing is made of one of PEEK, PA, PI, or PTFE.

[0014] In some implementations, the wall thickness of the sliding bearing is 2-5 mm.

[0015] In some implementations, the hub shell and the hub base are driven by a ratchet mechanism.

[0016] In some embodiments, the ratchet mechanism includes a toothed ring mounted on the hub shell and a jack hinged to the base.

[0017] In some implementations, the shaft is made of carbon fiber.

[0018] On the other hand, this utility model provides a hub, including the above-mentioned hub shaft limiting structure.

[0019] In summary, the beneficial effects of this utility model are as follows:

[0020] (1) This utility model simplifies the structure and optimizes the assembly process by setting a polymer sliding bearing between the second bearing and the third bearing to replace the original bushing, spacer and a rolling bearing. This reduces the number of parts, reduces the assembly difficulty and error rate, and significantly reduces the overall weight, thus meeting the requirements of high-performance bicycles for lightweight design.

[0021] (2) The polymer sliding bearing used in this utility model has excellent self-lubricating, wear-resistant and impact-resistant properties, which can effectively buffer axial micro-displacement, improve the stability of the shaft in the stress area, reduce the risk of stress concentration, extend service life, and enhance the durability and reliability of the structure under complex road conditions and long-term use. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the cross-sectional structure of the flower drum of this utility model;

[0023] Figure 2 This is a schematic diagram of the three-dimensional structure of this utility model.

[0024] The attached figures are labeled as follows:

[0025] 1. Hub shell; 2. Freeloader base; 3. Shaft; 4. First bearing; 5. Second bearing; 6. Third bearing; 7. Sliding bearing; 8. Ratchet mechanism. Detailed Implementation

[0026] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0027] As shown in the figure, a hub axle limiting structure includes a hub shell 1, a freehub base 2 that is drivenly connected to the hub shell 1, and an axle 3 that passes through the center of the hub shell 1 and the freehub base 2. The axle 3 is a through structure, with one end extending into the interior of the freehub base 2 and the other end extending to the other side of the hub shell 1, so as to achieve axial stable support for the entire hub system. In this embodiment, the axle 3 is made of carbon fiber material, which can effectively improve the rigidity of the hub and achieve lightweighting of the hub structure.

[0028] Between the hub shell 1 and the shaft 3, a first bearing 4 and a second bearing 5 are provided to support the shaft 3 and maintain low friction during rotation. The first bearing 4 is located near one end of the hub shell 1, and the second bearing 5 is located near the transition area between the hub shell 1 and the base 2.

[0029] A third bearing 6 is provided between the tower base 2 and the shaft 3. The third bearing 6 is located inside the tower base 2 on the side away from the hub shell 1, that is, at the end of the tower base 2. The third bearing 6 is used to strengthen the axial limiting and support function of the tower base end.

[0030] To further improve the overall stability of the structure and simplify the traditional assembly method, a sliding bearing 7 is provided between the second bearing 5 and the third bearing 6. This sliding bearing 7 is a polymer sliding bearing, which is sleeved on the outer surface of the shaft 3, with its outer wall abutting against the inner wall of the tower base 2, thus forming a stable supporting contact relationship. The two end faces of the sliding bearing 7 abut against the inner ring end faces of the second bearing 5 and the third bearing 6, respectively, thereby providing axial restraint and support, and effectively absorbing the impact or deviation caused by slight axial displacement.

[0031] Preferably, the material of the sliding bearing 7 is selected from one of PEEK (polyetheretherketone), PA (nylon), PI (polyimide), or PTFE (polytetrafluoroethylene). These materials have excellent wear resistance, low coefficient of friction, and good self-lubricating properties, making them suitable for auxiliary positioning in rotating structures. By using this type of polymer sliding bearing, the original bushing, spacer, and one rolling bearing can be omitted, greatly simplifying the internal structure, reducing the overall weight, decreasing the number of parts, and helping to improve the stability of the structure under high stress conditions.

[0032] Specifically, depending on the hub specifications, the wall thickness of the sliding bearing 7 is 2-5mm, which can meet the structural strength requirements and facilitate press-in installation.

[0033] More preferably, a ratchet device 8 is provided between the hub shell 1 and the freehub base 2 to achieve a one-way drive function and satisfy the decoupling of the rear wheel and pedal system during bicycle inertial gliding. The ratchet device 8 includes a gear ring installed inside the hub shell 1 and a spring jack structure hinged to the freehub base 2, and the transmission is achieved by the engagement of the spring jack with the gear ring.

[0034] The structural design in this embodiment combines the sliding support characteristics of polymer materials with the advantages of integrated assembly of structural components, which not only improves the durability and stability of the product, but also reduces the assembly complexity and production cost. It is particularly suitable for use in the rear hub system of high-performance bicycles such as road bikes and mountain bikes.

[0035] In one feasible implementation, the sliding bearing is injection molded from PEEK material with a wall thickness of 3mm. Its inner diameter is interference-fitted with the shaft 3 (tolerance H7 / p6), and its outer diameter is clearance-fitted with the inner wall of the tower base 2 (tolerance H8 / f7). Its two end faces are precision ground to Ra0.8 surface finish and are respectively in close contact with the inner ring end faces of the second bearing 5 and the third bearing 6.

[0036] During assembly, follow these steps:

[0037] 1. Press the first bearing 4 into the left end of the hub shell 1;

[0038] 2. Install shaft 3 and second bearing 5 in sequence;

[0039] 3. When pre-installing tower base 2, press-fit the third bearing 6 first;

[0040] 4. Finally, the sliding bearing 7 is sleeved on the shaft 3 and pressed into the inner cavity of the tower base 2, so that the sliding bearing 7 forms a pre-compression force (about 50N) in the axial direction.

[0041] Bench tests showed that this structure, compared to the traditional four-bearing design, demonstrates the following advantages:

[0042] Axial stiffness is increased by about 40%, assembly time is reduced by 35% (eliminating the need for selecting bearing gaskets and bushings), and weight is reduced by 18g (taking a 28-inch hub as an example).

[0043] In another embodiment, a hub is provided that has the above-mentioned hub axle limiting structure, which reduces the number of parts, reduces assembly difficulty and error rate, and significantly reduces the overall weight, thus meeting the lightweight design requirements of high-performance bicycles.

[0044] The technical solution of this utility model is illustrated below through an example of a flower drum.

[0045] Example 1

[0046] A polymer sliding bearing with a wall thickness of 3mm and a length of 10mm is made of polyetheretherketone (PEEK). It is sleeved on the outer surface of the shaft and abuts against the end faces of the second and third rolling bearings in sequence to form axial limiting. The hub weighs 284g and is assembled on the rear hub of a 700C highway.

[0047] Assembly records of five samples showed that it only took 32 seconds from picking up the part to locking it, while the average time for the conventional structure was 68 seconds.

[0048] The unloaded rotational resistance was measured to be 0.013 N·m under constant speed conditions of 23°C and 200 rpm.

[0049] After being subjected to an axial static pressure of 1000N for 60 seconds, the plastic deformation was 0.08mm, and no cracks were observed after a drop impact of 3kg×250mm.

[0050] The noise level in the semi-anechoic chamber was 48dB, and the resistance increase of the roller after 8000km of durability was less than 15% with no abnormal noise.

[0051] Example 2

[0052] In this embodiment, the sliding bearing material was replaced with polyimide (PI), while other structural elements remained the same. The hub weighed 286g. The average assembly time for this group of samples was 35 seconds under ambient temperature heat treatment.

[0053] No-load resistance: 0.015 N·m; static pressure and impact displacement: 0.09 mm; noise: 49 dB; test bench durability: 7500 km.

[0054] Immediately after braking down a 15km 12% slope, the rotational resistance showed no significant increase and the bearing appeared intact.

[0055] The results show that the PI version combines the advantages of high-temperature stability and lightweight design, and still maintains significant improvements in assembly efficiency, rolling resistance and strength compared to the traditional structure.

[0056] Example 3

[0057] In this embodiment, the sliding bearing is made of polytetrafluoroethylene (PTFE) material, weighs 282g, and is assembled on the rear hub of a mountain bike for a comprehensive test of salt spray-damp heat cycling and muddy road surface.

[0058] No corrosion was observed in the bearing and surrounding metal parts after 72 hours of salt spray and 100 hours of alternating wet heat.

[0059] No-load resistance: 0.014 N·m; static pressure and impact displacement: 0.11 mm; noise: 47 dB; performance remains within ±15% of initial value after 8000 km of roller fatigue.

[0060] This embodiment demonstrates the self-lubricating and corrosion-resistant properties, which can significantly extend maintenance intervals and reduce the risk of failure in harsh environments.

[0061] We tested the traditional structure of the hub using the test method described in the above embodiment. Please refer to Table 1 for the test data.

[0062]

[0063] Table 1

[0064] The results in Table 1 show that the introduction of single-piece polymer sliding bearings can reduce assembly time by more than half, decrease no-load rolling resistance by 32-41%, improve axial impact resistance by about three times, reduce overall drum weight by about 10%, and significantly extend maintenance intervals while maintaining or improving strength. This fully demonstrates the feasibility and comprehensive beneficial effects of this technical solution.

[0065] It should be noted that implementations not shown or described in the accompanying drawings or the main text of the specification are all forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the elements and methods described above are not limited to the various specific structures, shapes, or methods mentioned in the embodiments.

[0066] It should also be noted that this document may provide examples of parameters containing specific values, but these parameters need not be exactly equal to the corresponding values, but can approximate the corresponding values ​​within acceptable error tolerances or design constraints. Directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," "right," "inner," and "outer," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this application.

[0067] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A hub shaft limiting structure, characterized in that, It includes a hub shell (1), a freehub base (2) that is connected to the hub shell (1) in a transmission manner, and a shaft (3) that passes through the center of the hub shell (1) and the freehub base (2). A first bearing (4) and a second bearing (5) are provided between the hub shell (1) and the shaft (3), and a third bearing (6) is provided between the freehub base (2) and the shaft (3). The third bearing (6) is located inside the freehub base (2) on the side away from the hub shell (1). A sliding bearing (7) is provided between the second bearing (5) and the third bearing (6). The sliding bearing (7) is sleeved on the shaft (3) and its outer wall abuts against the inner wall of the tower base (2). The two end faces of the sliding bearing (7) abut against the inner ring end faces of the second bearing (5) and the third bearing (6), respectively.

2. The hub shaft limiting structure according to claim 1, characterized in that, The sliding bearing (7) is a polymer sliding bearing.

3. The hub shaft limiting structure according to claim 2, characterized in that, The material of the sliding bearing (7) is one of PEEK, PA, PI, or PTFE.

4. The hub shaft limiting structure according to claim 2, characterized in that, The wall thickness of the sliding bearing (7) is 2-5 mm.

5. The hub shaft limiting structure according to claim 1, characterized in that, The drum shell (1) and the base (2) are driven by a ratchet device (8).

6. The hub shaft limiting structure according to claim 5, characterized in that, The ratchet device (8) includes a toothed ring disposed on the drum shell (1) and a jack hinged to the base (2).

7. The hub shaft limiting structure according to claim 1, wherein The shaft (3) is made of carbon fiber material.

8. A flower drum, characterized in that, Includes the hub shaft limiting structure as described in any one of claims 1-7.

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