Novel crank middle shaft connecting structure
By introducing threaded fasteners and dust covers into the crankshaft connection structure, the problem of complicated disassembly steps in the prior art is solved, the middle shaft can be quickly disassembled, and the practicality and user experience of the bicycle are improved.
Patent Information
- Application Number
- CN202422758649.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-13
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-13
AI Technical Summary
The existing connection method between the crank and the bottom bracket requires complicated disassembly steps when replacing the crank, which affects the practical effect and user experience of the bicycle.
The fasteners and dust covers are threaded together, and the middle shaft and crank can be quickly disassembled by rotating the fasteners to press against the dust covers, thus simplifying the disassembly steps.
The disassembly process of the middle bracket is simplified, thereby improving the practical effect and user experience of the bicycle.
Smart Images
Figure CN223371068U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bicycle accessories, in particular to a novel crank shaft connection structure. Background Art
[0002] A bicycle, also known as a cycle or a bicycle, is a green and environmentally friendly means of transportation that people use to move by pedaling to drive the wheels. It is mainly composed of a body part, a transmission part, a movement part and a safety device. Among the various parts of a bicycle, in addition to some small bearings, there are mainly three major bearings, namely the front axle, the middle axle and the rear axle. The front and rear axles only need to withstand bending moments and do not rotate, and are fixed axles, while the middle axle withstands both bending moments and torques, and is a rotating axis. The middle axle is the axis used to connect the pedals through the crank, so the connection between the middle axle and the crank can affect the user's experience of the bicycle.
[0003] The current connection methods between crank and bottom bracket are as follows: Figure 1 As shown. Specifically, first, a through hole is opened on the crank 1', and then one end of the middle shaft 2' is inserted into the through hole on the crank 1', and finally a dust cover 3' is provided on the other end of the through hole. Among them, there is an interference fit between the middle shaft 2' and the through hole, and the end of the middle shaft 2' and the inner wall of the through hole are respectively provided with mutually engaging grooves and engaging teeth, so that the middle shaft 2' and the crank 1' are firmly engaged together. The dust cover 3' is fixedly arranged at the other end of the through hole to prevent external debris from entering the through hole, thereby preventing the middle shaft 2' and the inner wall of the through hole from rusting and corroding, thereby improving the service life of the middle shaft 2' and the crank 1'.
[0004] However, with this existing connection method, when the crank 1' and / or the bottom bracket 2' need to be replaced, it is first necessary to use a tool to remove the dust cover 3' from the through hole, and then use a professional disassembly tool 4' to remove the bottom bracket 2' from the crank 1'. This makes the disassembly steps cumbersome, thereby reducing the practical effect of the bicycle and affecting the user's experience. Therefore, this existing connection method has limitations. Utility Model Content
[0005] The utility model is developed to solve the above problems, and aims to provide a novel crank shaft connection structure.
[0006] The utility model provides a novel crank shaft connection structure, which has the following features: a crank, a shaft, a fastener and a dust cover.
[0007] A fixing hole for locking the middle shaft is opened on the end of the crank. The fixing hole has a left section, a right section, and a middle section connecting the left and right sections. The diameter of the middle section of the fixing hole is smaller than the diameters of the left and right sections of the fixing hole. Therefore, there is an annular stop step between the left and right sections of the fixing hole.
[0008] After the middle shaft is inserted into the left section of the fixing hole, it abuts against the stop step. The diameter of the middle shaft is not less than the diameter of the left section of the fixing hole. A slot is opened on one end face of the left section of the fixing hole and along the axis toward the inside thereof. The slot is not larger than the inner diameter of the stop step.
[0009] The fastener has an insertion section and a limiting section. The diameter of the insertion section is no larger than the inner diameter of the stopping step. The outer wall of the insertion section and the inner wall of the slot are respectively provided with an outer thread and an inner thread that engage with each other. The limiting section is larger than the diameter of the left section of the fixing hole and smaller than the diameter of the right section of the fixing hole.
[0010] The dust cover is annular, is arranged on the port of the right section of the fixing hole, and is engaged with the limiting section.
[0011] The new crank shaft connection structure provided by the present invention can also have the following features: convex keys are evenly distributed along the circumference on the inner wall of the left section of the fixing hole, and tooth grooves matching the convex keys are evenly distributed along the circumference on the outer wall of the shaft near one end thereof, so that the shaft cannot rotate after being inserted into the left section of the fixing hole.
[0012] The novel crank shaft connection structure provided by the present invention may also have the following features: an annular protrusion is provided at the junction of the insertion section and the limiting section, and an annular groove matching the annular protrusion is provided on the inner wall of the lower end of the dust cover.
[0013] The novel crankshaft connection structure provided by the present invention may also have the following feature: the outer wall of the dust cover and the inner wall of the right section of the fixing hole are respectively provided with meshing external threads and internal threads.
[0014] The novel crank shaft connection structure provided by the present invention can also have the following feature: the inner diameter of the dust cover is not less than the diameter of the limiting section.
[0015] The novel crank shaft connection structure provided by the present invention may also have the following feature: a slot for cooperating with a disassembly tool is provided on the end surface of the limiting section and inwardly along the axis.
[0016] Functions and effects of utility models
[0017] According to the novel crank axle connection structure involved in the present invention, it is intended that after the fastener is rotated using a disassembly tool, the dust cover and the fixing hole are threadedly connected, so that the fastener will press against the dust cover, and as the fastener rotates, the fastener and the axle will be disengaged, so that the fastener can push the axle out, so that there is no need to remove the dust cover and the axle can be removed from the crank with a disassembly tool once, thereby simplifying the disassembly steps, thereby improving the practical effect of the bicycle and enhancing the user experience. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the middle shaft and crank in the prior art;
[0019] Figure 2 It is an explosion diagram of the utility model;
[0020] Figure 3 It is a cross-sectional schematic diagram of the present utility model.
[0021] Description of reference numerals:
[0022] 1. Crank; 11. Fixing hole; 111. Left section; 112. Right section; 113. Middle section; 12. Stop step; 13. Key; 2. Central shaft; 21. Tooth socket; 22. Slot; 3. Fastener; 31. Insert section; 32. Limiting section; 33. Annular protrusion; 34. Slot; 4. Dust cover; 41. Annular groove. DETAILED DESCRIPTION
[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail in the following embodiments with reference to the accompanying drawings.
[0024] Example
[0025] Figure 2 This is an explosion diagram of the utility model. Figure 3 It is a cross-sectional schematic diagram of the present utility model.
[0026] like Figure 2 and Figure 3 As shown, this embodiment provides a novel crank axle connection structure, including: a crank 1, a axle 2, a fastener 3, and a dust cover 4.
[0027] In this embodiment, a fixing hole 11 for locking the middle shaft 2 is opened on the end of the crank 1. The fixing hole 11 has a left section 111, a right section 112, and a middle section 113 connecting the left section 111 and the right section 112. The diameter of the middle section 113 of the fixing hole is smaller than the diameters of the left section 111 and the right section 112 of the fixing hole. Therefore, there is an annular stopping step 12 between the left section 111 and the right section 112 of the fixing hole.
[0028] In this embodiment, the central shaft 2 is inserted into the left section 111 of the fixing hole 11 and abuts against the stopping step 12. The diameter of the central shaft 2 is not less than the diameter of the left section 111 of the fixing hole. The central shaft 2 is inserted into the end face of the left section 111 of the fixing hole and a slot 22 is opened inside the central shaft 2 along the axis. The slot 22 is not larger than the inner diameter of the stopping step 12.
[0029] In this embodiment, the inner wall of the left section 111 of the fixing hole is evenly distributed with convex keys 13 along the circumferential direction, and the outer wall of the central shaft 2 and near one end thereof are evenly distributed with grooves 21 matching the convex keys 13 along the circumferential direction, so that the central shaft 2 cannot rotate after being inserted into the left section 111 of the fixing hole 11.
[0030] In this embodiment, the fastener 3 comprises an insertion section 31 and a stop section 32. The diameter of the insertion section 31 is no larger than the inner diameter of the stop step 12. The outer wall of the insertion section 31 and the inner wall of the slot 22 are provided with intermeshing external and internal threads, respectively. The stop section 32 is larger than the diameter of the left section 111 of the fixing hole and smaller than the diameter of the right section 112 of the fixing hole. The stop section 32 preferably appears as a regular polygon, such as a regular hexagon or regular octagon, when viewed from above, to facilitate rotation of the stop section using an external angle wrench.
[0031] In this embodiment, a slot 34 for engaging a disassembly tool is formed on the end surface of the limiting segment 32 and extends inwardly along the axis thereof. The slot 34 preferably appears as a regular polygon, such as a regular hexagon or a regular octagon, when viewed from above, to facilitate the use of an internal angle wrench to rotate the limiting segment through the slot 34.
[0032] In this embodiment, the dust cover 4 is annular, is disposed on the end of the right section 112 of the fixing hole, and is engaged with the limiting section 32 .
[0033] In this embodiment, an annular protrusion 33 is provided at the junction of the insertion section 31 and the limiting section 32 , and an annular groove 41 matching the annular protrusion 33 is provided on the inner wall of the lower end of the dust cover 4 .
[0034] In this embodiment, the outer wall of the dust cover 4 and the inner wall of the right section 112 of the fixing hole are respectively provided with meshing external threads and internal threads.
[0035] In this embodiment, the inner diameter of the dust cover 4 is not less than the diameter of the limiting section 32 .
[0036] When in use, first insert one end of the middle shaft 2 into the left section 111 of the fixing hole 11 on the crank 1, so that the middle shaft 2 and the crank 1 are preliminarily locked, and then insert the fastener 3 into the right section 112 of the fixing hole 11, and rotate the fastener 3 so that the insertion section 31 of the fastener 3 is threadedly locked with the slot 22 on the middle shaft 2, so that the middle shaft 2 and the crank 1 are finally locked, and finally screw the dust cover 4 into the right section 112 of the fixing hole 11, and make the inner wall of the dust cover 4 close to the outer wall of the fastener 3, so as to prevent foreign matter from entering the fixing hole 11. During disassembly, it is only necessary to use a disassembly tool to rotate the fastener 3. At this time, since the dust cover 4 and the right section 112 of the fixing hole 11 are threadedly connected, the fastener 3 will press against the dust cover 4, and as the fastener 3 rotates, the insertion section 31 of the fastener 3 will be disengaged from the slot 22 on the middle shaft 2, so that the fastener 3 can push the middle shaft 2 out, so that there is no need to remove the dust cover 4, and the middle shaft 2 can be removed from the crank 1 using only one disassembly tool.
[0037] Functions and Effects of the Embodiments
[0038] According to the novel crank axle connection structure involved in the present invention, it is intended that after the fastener is rotated using a disassembly tool, the dust cover and the fixing hole are threadedly connected, so that the fastener will press against the dust cover, and as the fastener rotates, the fastener and the axle will be disengaged, so that the fastener can push the axle out, so that there is no need to remove the dust cover and the axle can be removed from the crank with a disassembly tool once, thereby simplifying the disassembly steps, thereby improving the practical effect of the bicycle and enhancing the user experience.
[0039] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.
Claims
1. A new crankshaft connection structure, characterized in that: include: Cranks, bottom brackets, fasteners and dust covers, A fixing hole for locking the central shaft is provided on the end of the crank, and the fixing hole has a left section, a right section, and a middle section connecting the left section and the right section. The diameter of the middle section of the fixing hole is smaller than the diameters of the left section and the right section of the fixing hole, so there is an annular stopping step between the left section and the right section of the fixing hole. The central shaft is inserted into the left section of the fixing hole and abuts against the stopping step. The diameter of the central shaft is not less than the diameter of the left section of the fixing hole. The central shaft is inserted into the end surface of the left section of the fixing hole and a slot is opened inside the central shaft along the axis. The slot is not larger than the inner diameter of the stopping step. The fastener comprises an insertion section and a limiting section, wherein the diameter of the insertion section is not larger than the inner diameter of the stopping step, the outer wall of the insertion section and the inner wall of the slot are respectively provided with an outer thread and an inner thread which engage with each other, and the limiting section is larger than the diameter of the left section of the fixing hole and smaller than the diameter of the right section of the fixing hole. The dust cover is annular, is arranged on the port of the right section of the fixing hole, and is engaged with the limiting section.
2. The novel crankshaft connection structure according to claim 1 is characterized in that: in, The inner wall of the left section of the fixing hole is evenly provided with convex keys along the circumferential direction, and the outer wall of the central shaft is evenly provided with grooves matching the convex keys along the circumferential direction near one end thereof, so that the central shaft cannot rotate after being inserted into the left section of the fixing hole.
3. The novel crankshaft connection structure according to claim 1 is characterized in that: in, An annular protrusion is provided at the junction of the insertion section and the limiting section, and an annular groove matching the annular protrusion is provided on the inner wall of the lower end of the dust cover.
4. The novel crankshaft connection structure according to claim 1 is characterized in that: in, The outer wall of the dust cover and the inner wall of the right section of the fixing hole are respectively provided with meshing external threads and internal threads.
5. The novel crankshaft connection structure according to claim 1 is characterized in that: in, The inner diameter of the dust cover is not less than the diameter of the limiting section.
6. The novel crankshaft connection structure according to claim 1 is characterized in that: in, A slot for cooperating with a disassembly tool is provided on the end surface of the limiting section and inwardly along the axis.