Bicycle crank

Abstract

The utility model relates to a bicycle crank which comprises a crank assembly and an axis sleeve. The crank assembly is in an L shape and comprises a crank part and a rotating axis part which are integrally formed. The rotating axis part is sleeved with the axis sleeve. According to the technical scheme, the carbon fiber crank with the rotating axis integrally formed is provided, the weight of the crank is remarkably reduced, and meanwhile the overall rigidity and strength of the crank are improved. According to the scheme, during machining, unnecessary installation and splicing procedures are reduced, the production and machining efficiency is improved, and the whole crank is attractive and elegant.

Description

Technical Field

[0001] This utility model relates to the field of carbon fiber composite material technology, and in particular to a bicycle crank. Background Technology

[0002] Bicycles are a convenient mode of transportation. In recent years, with the promotion of green travel, cycling has become a healthy, environmentally friendly, and fashionable mode of transportation. People's requirements for bicycles have also evolved from durability and lightness to green and stylish design. Although bicycles seem simple, they actually combine ergonomics, dynamics, mechanics, aesthetics, and many other aspects of comprehensive design.

[0003] In this bicycle system, transmission is achieved through the cooperation of a front sprocket and a rear sprocket. The front sprocket is the drive sprocket and is connected to the pedals via a crank. The crank typically includes a main shaft hole and a secondary shaft hole. The main shaft hole mates with the central shaft of the front sprocket, while the secondary shaft hole mates with the pedals. An embedded or glued metal bushing is located inside the main shaft hole to mate with the central shaft of the front sprocket. This requires additional metal parts, pre-treatment, and gluing processes, increasing the overall rotational weight of the crank assembly. This is highly detrimental to the development and production of lightweight cranks, and the modular design makes the crank components less robust. Utility Model Content

[0004] Therefore, it is necessary to provide a bicycle crank that addresses the problems of existing cranks being too lightweight and cumbersome to manufacture.

[0005] A bicycle crank includes: a crank assembly and an axle sleeve; the crank assembly is L-shaped and includes an integrally formed crank portion and a rotating axle portion; the axle sleeve is fitted onto the rotating axle portion. The crank assembly is integrally formed from carbon fiber material. The axle sleeve is made of metal material, including aluminum alloy and titanium alloy. The axle sleeve is glued and fixed to the rotating axle, or it can be integrally formed together with the axle portion.

[0006] Furthermore, the crank assembly has a hollow structure, and the inner wall of the crank assembly is provided with reinforcing ribs.

[0007] This invention proposes a carbon fiber crank with an integrally molded rotating shaft, which significantly reduces the weight of the crank while improving its overall rigidity and strength. Furthermore, this design reduces unnecessary assembly and splicing procedures during manufacturing, accelerating production efficiency, and resulting in a more aesthetically pleasing overall crank. Attached Figure Description

[0008] Figure 1 This is a perspective view of an embodiment of the present utility model;

[0009] Figure 2 This is a front view of an embodiment of the present invention;

[0010] Figure 3 This is a perspective view of the crank assembly according to an embodiment of the present invention;

[0011] Figure 4 This is a front view of the crank assembly according to an embodiment of the present invention;

[0012] Figure 5 This is a schematic diagram of the structure of the shaft sleeve according to an embodiment of the present utility model;

[0013] Figure 6 This is a left view of the crank assembly according to an embodiment of the present invention;

[0014] Figure 7 for Figure 6 A schematic diagram of the cross-section along the AA direction;

[0015] Figure 8 This is a left view of the shaft sleeve according to an embodiment of the present invention;

[0016] Figure 9 for Figure 8 A schematic diagram of the cross-section in the BB direction.

[0017] The attached diagram lists the components represented by each number as follows:

[0018] 1. Crank assembly; 11. Crank section; 12. Rotating shaft section; 13. Reinforcing rib; 2. Shaft sleeve. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described clearly and completely below with reference to the accompanying drawings. Obviously, the specific details described below are only a part of the embodiments of this utility model, and this utility model can be implemented in many other embodiments different from those described herein. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0022] In one embodiment, please refer to Figures 1 to 9 As shown, a bicycle crank includes a spindle sleeve 2 and a crank assembly 1. The crank assembly 1 is L-shaped and includes an integrally formed crank portion 11 and a rotating spindle portion 12. The spindle sleeve 2 is fitted onto the rotating spindle portion 12. This utility model provides a carbon fiber crank with an integrally formed rotating spindle, significantly reducing the crank's weight while improving its overall rigidity and strength. Furthermore, this design reduces unnecessary assembly and splicing procedures during processing, accelerating production efficiency, and resulting in a more aesthetically pleasing overall crank.

[0023] The crank assembly 1 is integrally molded from carbon fiber material. High-performance carbon fiber possesses a series of superior properties that are irreplaceable by other materials, including light weight, high strength, high modulus, high temperature resistance, corrosion resistance, erosion and sputtering resistance, and excellent designability and compositeability. The aforementioned axle sleeve 2 is made of metal materials, including aluminum alloy and titanium alloy. The axle sleeve 2 is glued to the pedal axle 12 to prevent loosening. Alternatively, it can be integrally molded together with the axle.

[0024] Based on this embodiment, the crank assembly 1 has a hollow structure, and the inner wall of the crank assembly 1 is provided with reinforcing ribs 13. On the one hand, the hollow structure can greatly reduce the weight of the crank, achieving a lightweight effect; on the other hand, the reinforcing ribs 13 can effectively strengthen the crank and prevent crank breakage.

[0025] In this embodiment, the surface of the rotating shaft 12 is provided with protrusions or concave areas; the inner sidewall of the shaft sleeve 2 is provided with corresponding concave or protrusions to circumferentially fix the shaft sleeve 2 and the rotating shaft 12. The concave-convex fit structure can effectively prevent slippage.

[0026] In this embodiment, the crank production process is as follows: S1 carbon fiber prepreg; S2 cutting; S3 material preparation; S4 pre-forming (EPS core + nylon air bag, internal metal parts of the countershaft); S5 placing in the mold; S6 hot table blowing molding (30 minutes); S7 cold table cooling (10 minutes).

[0027] The present invention has the following advantages: the one-piece molded carbon fiber rotating shaft eliminates the need for a metal spindle sleeve, saving weight and simplifying the manufacturing process; the one-piece molded carbon fiber rotating shaft replaces the metal shaft, resulting in a lighter design and reducing the weight of the entire crank assembly by more than 10%; the continuous reinforcing ribs 13 in the middle of the cavity significantly improve the overall strength and rigidity of the crank, which helps with power generation and comfort during riding.

[0028] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications, substitutions, and improvements without departing from the concept of this utility model, and these should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the claims.

Claims

1. A bicycle crank, characterized in that The application relates to a crank assembly and a shaft sleeve. The crank assembly is integrally formed by carbon fiber material.

2. The bicycle crank of claim 1, wherein The shaft sleeve is made of metal material.

3. The bicycle crank of claim 1, wherein, The shaft sleeve is glued to the rotating shaft part or integrally formed with the crank assembly.

4. The bicycle crank of claim 1, wherein, The crank assembly is a hollow structure, and the inner wall of the crank assembly is provided with reinforcing ribs.

5. The bicycle crank of claim 1, wherein, The rotating shaft part is provided with a protrusion or an inner recess, and the inner wall of the shaft sleeve is provided with an inner recess or a protrusion matched with the rotating shaft part, so that the shaft sleeve and the rotating shaft part are circumferentially fixed.

6. The bicycle crank of claim 1, wherein, ​

Images