Tower footing and hub driving structure

Abstract

The utility model discloses a tower footing and hub driving structure. The tower footing and hub driving structure comprises a tower footing shell, an outer tooth piece arranged at one end of the tower footing shell and a second transmission ratchet wheel connected with the outer tooth piece in a meshed mode. The outer tooth piece comprises an outer tooth piece outer ring provided with outer teeth; inner teeth are arranged on the inner ring of the second transmission ratchet wheel and matched with the outer ring of the outer tooth piece. Therefore, the transmission area of the second transmission ratchet wheel is larger, the meshing area is larger, the force loss can be reduced in the driving process, and the force transmission efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of bicycle accessories, and specifically relates to a freehub body and a hub drive structure. Background Art

[0002] The current freehub body structure on the market mainly relies on a ratchet mechanism to achieve one-way power transmission through the engagement of a ratchet and a freewheel. However, this design has some significant drawbacks. Insufficient engagement area is a major problem. In the existing freehub body structure, the contact area between the ratchet engaged with the freehub body and the ratchet on the hub is small. This will cause stress concentration during high-torque transmission, accelerating the ratchet teeth from slipping. If the strength of the ratchet material is insufficient, the ratchet needs to be frequently replaced. In addition, the small engagement area also affects the efficiency of power transmission. When the rider pedals the pedal, the force loss is more serious, affecting the driving of the wheel. Summary of the Utility Model

[0003] In order to overcome the deficiencies of the prior art, the utility model provides a freehub body and a hub drive structure with greater engagement strength and longer service life.

[0004] The first technical solution adopted by the utility model to solve its technical problems is:

[0005] It includes a freehub body housing, an external tooth member provided at one end of the freehub body housing, and a second transmission ratchet engaged with the external tooth member;

[0006] The external tooth member includes an external tooth member outer ring provided with external teeth;

[0007] The inner ring of the second transmission ratchet is provided with internal teeth, and the internal teeth are matched with the external tooth member outer ring.

[0008] For the freehub body as described above, the external tooth member further includes an external tooth member outer ring, and the diameter of the second transmission ratchet is 30 mm - 50 mm.

[0009] For the freehub body as described above, it further includes a mounting groove provided on the outer peripheral side of the external tooth member; an elastic member and the external tooth member are installed in the mounting groove, and the elastic member is located between the external tooth member and the inner wall of the mounting groove.

[0010] For the freehub body as described above, the elastic member is a spring, and the diameter of the elastic member is greater than the inner diameter of the freehub body housing and less than the outer diameter of the mounting groove.

[0011] For the freehub body as described above, the elastic member is a conical helical spring.

[0012] The second technical solution adopted by the utility model to solve its technical problems is:

[0013] A hub drive structure includes the above-mentioned freehub body and a hub assembly. The hub assembly includes a hub shell, a first drive ratchet fixedly connected inside the hub shell, and an engagement space provided at one end of the hub shell and adjacent to the first drive ratchet. A first tooth surface is provided on one side of the first drive ratchet facing the engagement space;

[0014] A second tooth surface is provided on one side of the second drive ratchet facing the engagement space, and the second tooth surface and the first tooth surface are mutually meshing surfaces;

[0015] The included angle between the first tooth surface and the rotation axis of the first drive ratchet is α, and the included angle between the second tooth surface and the rotation axis of the second drive ratchet is α; wherein, α > 0°.

[0016] For the hub drive structure as described above, α ≤ 30°.

[0017] For the hub drive structure as described above, the first tooth surface is concavely arranged towards the central axis of the first drive ratchet; the second tooth surface is convexly arranged along the central axis of the second drive ratchet.

[0018] For the hub drive structure as described above, an external thread is provided on the outer peripheral side of the first drive ratchet, and an internal thread matching the external thread is provided inside the hub shell.

[0019] For the hub drive structure as described above, the depth of the engagement space is greater than the thickness of the second tooth surface.

[0020] The beneficial effects of the present utility model are:

[0021] The freehub body includes a freehub body shell, an external tooth member provided at one end of the freehub body shell, and a second drive ratchet meshingly connected with the external tooth member; during use, the freehub body shell and the external tooth member are installed outside the axle, and the second drive ratchet has no direct contact with the axle; compared with the prior art, the inner ring of the second drive ratchet is sleeved outside the axle, and the outer diameter of the second drive ratchet is smaller than the diameter of the freehub body shell; in this solution, the transmission area and the meshing area of the second drive ratchet are larger, and the loss of force can be reduced during the driving process, improving the force transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present utility model will be further described below with reference to the drawings and embodiments.

[0023] Figure 1 is a top view of the freehub body in the prior art;

[0024] Figure 2 is a top view of the freehub body in this embodiment;

[0025] Figure 3 is one of the structural schematic diagrams of the freehub body;

[0026] Figure 4 It is the second structural schematic diagram of the tower base;

[0027] Figure 5 It is the structural schematic diagram of the hub drive mechanism;

[0028] Figure 6 It is the cross-sectional view of the hub drive structure;

[0029] Figure 7 It is Figure 6 the enlarged structural view of part A in

[0030] Figure 8 It is Figure 6 the enlarged structural view of part B in

[0031] Figure 9 It is the exploded view of the hub drive structure;

[0032] The reference numerals are as follows:

[0033] 1 - Hub assembly; 2 - Tower base; 11 - Hub housing; 12 - First drive ratchet; 13 - Meshing space; 121 - First tooth surface; 21 - Tower base housing; 22 - Elastic member; 23 - Second drive ratchet; 231 - Second tooth surface; 24 - Installation groove; 211 - External tooth member; 212 - Outer ring of the external tooth member; 213 - Inner ring of the external tooth member; 233 - Contact surface. Detailed implementation manners

[0034] The concept, specific structure and technical effects of the present utility model will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present utility model. Obviously, the described embodiments are only a set of embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model. In addition, all the connection / connection relationships involved in the patent do not simply refer to the direct connection of components, but refer to the more optimal connection structure that can be formed by adding or reducing connection accessories according to the specific implementation situation. Each technical feature in the creation of the present utility model can be interactively combined without mutual contradiction and conflict.

[0035] The hub and the tower base are the core of the bicycle transmission. The hub is a component at the center of the bicycle wheel, responsible for transmitting the power of the pedal to the wheel to make the wheel rotate. The hub contains bearings inside, and these bearings support the rotation of the wheel and reduce friction, which is an indispensable part of the bicycle transmission system. The tower base is a component installed on the hub. It carries the freewheel and allows the chain to mesh with the freewheel, thereby transmitting the power of the pedal to the hub and the wheel.

[0036] When the rider pedals, it drives the base tower to engage with the one-way gear set on the hub, thereby driving the wheel to rotate. When the rider stops pedaling, the wheel and the hub rotate under the action of inertia, while the base tower remains relatively stationary and the base tower idles relative to the hub. Therefore, in the prior art, if the one-way gear set slips, it will affect the transmission stability of the hub and the base tower.

[0037] The base tower structure in the prior art refers to Figure 1 , in the existing base tower housing 9, meshing teeth 91 are provided, and the ratchet 92 meshes with the meshing teeth 91 and is installed in the base tower housing 9; it can be seen that the area of the ratchet 92 is small, and the meshing area with the ratchet on the hub set is correspondingly small.

[0038] In view of the above defects, the following solution is proposed in this embodiment:

[0039] Referring to Figures 2 - 9 , a base tower, characterized in that: it includes a base tower housing 21, an external tooth member 211 provided at one end of the base tower housing 21, and a second transmission ratchet 23 meshingly connected with the external tooth member 211;

[0040] The external tooth member 211 includes an external tooth member outer ring 212 provided with external teeth;

[0041] The inner ring of the second transmission ratchet 23 is provided with inner teeth 231, and the inner teeth 231 match the external tooth member outer ring 212.

[0042] Compared with the prior art, when the outer diameter of the base tower housing 21 is fixed, the inner installation of the ratchet is on the axle; in this solution, the external tooth member 211 is installed on the axle through the inner ring 213 of the external tooth member, and after the second transmission ratchet 23 meshes with the external tooth member 211, it is not directly connected to the axle. Compared with the prior art, the transmission area is larger, the meshing area is larger, the loss of force can be reduced during the driving process, and the transmission efficiency of force can be improved.

[0043] Based on the above structure, the outer diameter of the ratchet in the prior art is 27.7 mm, while adopting the solution in this embodiment, the inner diameter of the second transmission ratchet 23 can reach 27.7 mm.

[0044] In one embodiment, the outer diameter of the second transmission ratchet 23 is 30 mm - 50 mm; such as 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm.

[0045] Referring to Figures 8 - 9, in one embodiment, the tower base 2 further includes an installation groove 24 provided on the peripheral side of the external tooth member 211; an elastic member 22 and the external tooth member 211 are installed in the installation groove 24, and the elastic member 22 is located between the external tooth member 211 and the inner wall of the installation groove 24. When the elastic member 22 expands, it drives the second transmission ratchet wheel 23 to move towards the direction of the hub assembly 1.

[0046] Specifically, the elastic member 22 is a spring, and the diameter of the elastic member 22 is greater than the inner diameter of the tower base housing 21 and less than the outer diameter of the installation groove 24. Compared with installing several springs with an inner diameter less than the inner diameter of the tower base housing 21 and the outer diameter of the installation groove 24 in the installation groove 24, the elastic force provided by the spring along the peripheral side of the external tooth member 211 in this embodiment is uniform, which can improve the stability of the tower base 2.

[0047] More specifically, the elastic member 22 is a conical helical spring; when the conical helical spring is completely compressed, the height of the conical helical spring is relatively small, making the structure of the tower base 2 more compact.

[0048] This embodiment also provides a hub drive structure, which includes the tower base 2 and the hub assembly 1 described in any one of the above embodiments. The hub assembly 1 includes a hub housing 11, a first transmission ratchet wheel 12 fixedly connected in the hub housing 11, and an engagement space 13 provided at one end of the hub housing 11 and adjacent to the first transmission ratchet wheel 12. A first tooth surface 121 is provided on one side of the first transmission ratchet wheel 12 facing the engagement space 13;

[0049] A second tooth surface 232 is provided on one side of the second transmission ratchet wheel 23 facing the engagement space 13, and the second tooth surface 232 and the first tooth surface 121 are mutually meshing surfaces;

[0050] The included angle between the first tooth surface 121 and the rotation axis of the first transmission ratchet wheel 12 is α, and the included angle between the second tooth surface 232 and the rotation axis of the second transmission ratchet wheel 23 is α; wherein, α > 0°.

[0051] In one embodiment, α ≤ 30°.

[0052] Further, α is 10°.

[0053] As an example for understanding the working principle of the present device: the teeth of the second tooth surface 232 are inclined in the clockwise direction, the opening of the tooth groove of the first tooth surface 121 faces in the counterclockwise direction. When the rider steps on the pedal, the elastic member 22 unfolds, driving the freehub body 2 to move towards the direction of the hub assembly 1. The second tooth surface 232 is attached to the first tooth surface 121, and the teeth of the second tooth surface 232 are inserted into the tooth grooves of the first tooth surface 121, thereby driving the hub assembly 1 to rotate. When stopping stepping on the pedal, the hub assembly 1 rotates clockwise relative to the freehub body 2, and the teeth of the second tooth surface 232 are not inserted into the tooth grooves of the first tooth surface 121, and the first drive ratchet 12 idles relative to the second drive ratchet 23.

[0054] In this embodiment, the compression and unfolding of the elastic member 22 drive the second drive ratchet 23 to move, and the external teeth on the outer ring 212 of the external tooth member also have the function of guiding the second drive ratchet 23.

[0055] In one embodiment, the first tooth surface 121 is concavely arranged towards the central axis of the first drive ratchet 12; the second tooth surface 232 is convexly arranged along the central axis of the second drive ratchet 23. The required transmission ratio can be achieved in a smaller meshing space 13, and the structure is more compact.

[0056] In one embodiment, the first drive ratchet 12 is threadedly connected to the hub housing 11. For example, when the first drive ratchet 12 is damaged, it is convenient to remove and replace it from the hub housing 11.

[0057] Further, an external thread is provided on the outer peripheral side of the first drive ratchet 12, and an internal thread matching the external thread is provided in the hub housing 11.

[0058] Further, the transverse diameter of the meshing space 13 is larger than the transverse diameter of the mounting groove 24.

[0059] Further, the depth of the meshing space 13 is larger than the thickness of the second tooth surface 232.

[0060] The above is a specific description of the preferred embodiments of the present utility model, but the present utility model is not limited to the above embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present utility model, and these equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A tower foundation, characterized in that: It comprises a freehub base housing (21), an external toothed part (211) arranged at one end of the freehub base housing (21), and a second transmission ratchet (23) meshingly connected to the external toothed part (211); The external toothed member (211) comprises an external toothed member outer ring (212) provided with external teeth; The inner ring of the second transmission ratchet (23) is provided with inner teeth (231), and the inner teeth (231) match the outer ring (212) of the outer tooth member.

2. The tower foundation according to claim 1, characterized in that: The diameter of the second transmission ratchet (23) is 30 mm-50 mm.

3. The tower foundation according to claim 1, characterized in that: It also includes a mounting groove (24) arranged on the outer peripheral side of the external tooth part (211); an elastic part (22) and the external tooth part (211) are installed in the mounting groove (24), and the elastic part (22) is located between the external tooth part (211) and the inner wall of the mounting groove (24).

4. The tower foundation according to claim 3, characterized in that: The elastic member (22) is a spring, and the diameter of the elastic member (22) is larger than the inner diameter of the tower base housing (21) and smaller than the outer diameter of the installation groove (24).

5. The tower foundation according to claim 4, characterized in that: The elastic member (22) is a conical helical spring.

6. A hub driving structure, characterized in that: The invention comprises a freewheel base (2) and a hub assembly (1) as claimed in any one of claims 1 to 5, wherein the hub assembly (1) comprises a hub shell (11), a first transmission ratchet (12) fixedly connected to the hub shell (11), and a meshing space (13) provided at one end of the hub shell (11) and adjacent to the first transmission ratchet (12), wherein the first transmission ratchet (12) is provided with a first tooth surface (121) on a side facing the meshing space (13); A second tooth surface (232) is provided on a side of the second transmission ratchet (23) facing the meshing space (13), and the second tooth surface (232) and the first tooth surface (121) are meshing surfaces with each other; The angle between the first tooth surface (121) and the rotation axis of the first transmission ratchet (12) is α, and the angle between the second tooth surface (232) and the rotation axis of the second transmission ratchet (23) is α; wherein α>0°.

7. The hub driving structure according to claim 6, characterized in that: The α is ≤30°.

8. The hub driving structure according to claim 6, characterized in that: The first tooth surface (121) is arranged concavely toward the central axis of the first transmission ratchet (12); and the second tooth surface (232) is arranged convexly along the central axis of the second transmission ratchet (23).

9. The hub driving structure according to claim 7, characterized in that: The outer peripheral side of the first transmission ratchet (12) is provided with an external thread, and the hub shell (11) is provided with an internal thread matching the external thread.

10. The hub driving structure according to claim 6, characterized in that: The depth of the meshing space (13) is greater than the thickness of the second tooth surface (232).

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