Bicycle middle shaft, crank and sprocket combination structure convenient to disassemble

Abstract

This utility model discloses a bicycle bottom bracket, crank, and sprocket assembly structure that is easy to assemble and disassemble, relating to the field of bicycle assembly and disassembly technology. It includes a sprocket unit, a bottom bracket unit, and a crank unit. The bottom bracket unit has two ends that respectively engage with the sprocket unit and the crank unit. It contains symmetrical stabilizing components and engaging components. The first and second engaging connectors of the engaging components are respectively adapted to the sprocket and crank connectors, and all four components have identical structures and are symmetrically distributed. They interlock through a "clamp head-clamp hole" mechanism, forming a square hole for inserting a stabilizing locking strip. The locking strip has sealing plugs at both ends. This structure requires no special tools; assembly can be completed simply by pushing in, inserting the locking strip, and pressing the sealing plugs. Disassembly is simple, the connection is stable and prevents abnormal noise, the positioning is precise and easy to maintain, and it is compatible with various types of bicycles.

Description

Technical Field

[0001] This utility model relates to the field of bicycle assembly and disassembly technology, and in particular to a bicycle bottom bracket, crank, and sprocket combination structure that is easy to assemble and disassemble. Background Technology

[0002] The combination of the bicycle bottom bracket, crank, and sprocket is a core component for transmitting pedaling power. The ease of assembly and disassembly directly determines maintenance efficiency and operating costs. However, existing technologies have several shortcomings that urgently need to be addressed: threaded bottom brackets require repeated tightening of the housing with a wrench for assembly and disassembly, while press-fit bottom brackets rely on a dedicated puller, which is time-consuming and can easily damage the bottom bracket of the frame; cranks and bottom brackets are mostly fastened with bolts or interference fits, requiring a puller to separate square-hole cranks, and a dedicated wrench is also needed to remove the locking cap of splined cranks, resulting in high tool dependence; sprockets are connected to the cranks by multiple circumferentially distributed bolts, requiring individual tightening during assembly and disassembly, and the locating pins are prone to misalignment due to improper operation. These problems make it difficult for ordinary users to perform maintenance independently, increasing subsequent repair costs and reducing the timeliness of equipment maintenance. Therefore, there is an urgent need for a new combination structure that can overcome tool dependence, simplify the assembly and disassembly process, and ensure positioning accuracy. Utility Model Content

[0003] In view of the shortcomings of the existing technology, this utility model provides a bicycle bottom bracket, crank, and sprocket combination structure that is easy to disassemble and assemble, thus solving the problem of quick connection between the bicycle bottom bracket, crank, and sprocket.

[0004] To achieve the above objectives, this utility model provides the following technical solution: A bicycle bottom bracket, crank, and sprocket assembly structure that is easy to disassemble and assemble includes a sprocket unit, a bottom bracket unit, and a crank unit. The bottom bracket unit has the sprocket unit and the crank unit respectively snapped onto its two ends. The bottom bracket unit is provided with two symmetrical stabilizing components and snap-fit ​​components. The stabilizing component includes a stabilizing strip, and the two ends of the stabilizing strip are symmetrically provided with blocking plugs; The snap-fit ​​assembly is symmetrically provided with a first snap-fit ​​connector and a second snap-fit ​​connector, and the appearance of the first snap-fit ​​connector and the second snap-fit ​​connector is the same as the internal structure. The crank unit is provided with a crank connector, which is adapted to the second locking connector. The crank connector and the second locking connector have the same appearance and internal structure, and the crank connector and the second locking connector are centrally symmetrically distributed. The sprocket unit is provided with a sprocket connector, which is adapted to the first snap-fit ​​connector. The sprocket connector and the first snap-fit ​​connector have the same appearance and internal structure, and the sprocket connector and the first snap-fit ​​connector are centrally symmetrically distributed.

[0005] Preferably, the sprocket unit is further provided with a sprocket, the sprocket is made of alloy, and the sprocket connector is fixedly connected to the center of one end of the sprocket.

[0006] Preferably, the snap-fit ​​assembly further includes a first adapter cap and a second adapter cap. The appearance of the first adapter cap and the second adapter cap are the same as their internal structure. The first adapter cap and the second adapter cap are arranged in a mirror symmetrical manner. One end of the first adapter cap is fixedly connected to the first snap-fit ​​connector, and one end of the second adapter cap is fixedly connected to the second snap-fit ​​connector. A shaft cylinder is connected between the first adapter cap and the second adapter cap. The shaft cylinder is cylindrical.

[0007] Preferably, the crank unit further includes a handle, one end of which is fixedly connected to the crank connector.

[0008] Preferably, the stabilizing strip includes a square strip, and the square strip has a plug hole; The barrier plug includes a plug head, which is cylindrical, and a plug strip is fixedly connected to the center of the plug head. The plug strip is adapted to the plug hole and is made of rubber.

[0009] Preferably, the sprocket connector, the first locking connector, the crank connector, and the second locking connector have the same structure, each equipped with a locking post. The locking post is a cylindrical base with a locking hole, which is a square hole. A stabilizing half-post is fixedly connected to the locking post. The stabilizing half-post is a semi-cylinder with a groove, which is a triangular groove. A locking head is fixedly connected to the other end of the stabilizing half-post. The size of the locking head matches the size of the locking hole. The two symmetrically arranged grooves form a square hole that matches the stabilizing locking strip.

[0010] Compared with the prior art, the present invention has the following beneficial effects: With its interlocking "clamp head-clamp hole" design and secure clamping strip insertion, the connection between the sprocket, crank, and bottom bracket does not require wrenches, pullers, or other professional tools. Assembly can be completed simply by horizontally pushing, inserting the clamping strip, and pressing the blocking plug. Disassembly can be completed by removing the plug, pulling out the clamping strip, and pulling out the connector. Compared with traditional structures, the disassembly and assembly efficiency is greatly improved, and ordinary users can operate it independently.

[0011] The snap-fit ​​connector and the connector achieve initial positioning by inserting the snap-fit ​​connector into the snap-fit ​​hole. After fitting, the square hole formed by the splicing groove is precisely matched with the stabilizing snap-fit ​​strip, forming a double fixing structure of "radial interlocking + axial clamping". With the help of the barrier plug for sealing and dust prevention, it can prevent dust intrusion and component loosening and corrosion, and ensure that there is no deviation or abnormal noise during the transmission process.

[0012] The shape matching of the chuck head and the chuck hole, along with the alignment and guiding function of the slots, provides a clear positioning benchmark for the assembly process, avoiding problems such as sprocket misalignment and crank reverse installation in traditional multi-bolt connections; precise assembly can be completed without professional experience, ensuring the power transmission efficiency of the transmission system.

[0013] The central shaft unit is composed of an adapter cap, shaft sleeve, and snap-fit ​​connector. The sprocket and crank are assembled through independent connectors. When local wear occurs, the corresponding parts can be replaced individually without replacing the entire assembly. The dustproof design of the barrier plug further reduces component wear and extends the service life of the assembly. Attached Figure Description

[0014] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is an exploded view of the overall structure of this utility model; Figure 3 This is a schematic diagram of the sprocket unit in this utility model; Figure 4 This is a schematic diagram of the snap-fit ​​assembly in this utility model; Figure 5 This is an exploded structural diagram of the snap-fit ​​assembly in this utility model; Figure 6 This is a schematic diagram of the crank unit in this utility model; Figure 7 This is a schematic diagram of the stabilizing component in this utility model; Figure 8 This is a schematic diagram illustrating the operation of the sprocket connector and the first locking connector in this utility model; Figure 9 This is a schematic diagram illustrating the operation of the blocking plug and the stabilizing strip in this utility model; Figure 10 This is a schematic diagram of the structure of the sprocket connector, the first locking connector, the crank connector, and the second locking connector in this utility model.

[0016] Legend: 1. Sprocket unit; 11. Sprocket; 12. Sprocket connector; 2. Central shaft unit; 21. Stabilizing component; 211. Stabilizing clip; 2111. Square; 2112. Plug hole; 212. Barrier plug; 2121. Plug head; 2122. Plug strip; 22. Snap-fit ​​component; 221. First adapter cap; 222. First snap-fit ​​connector; 223. Shaft cylinder; 224. Second adapter cap; 225. Second snap-fit ​​connector; 3. Crank unit; 31. Crank connector; 32. Handle; 01. Snap-fit ​​post; 02. Snap hole; 03. Stabilizing half post; 04. Groove; 05. Clip head. Detailed Implementation

[0017] This application provides a bicycle bottom bracket, crank, and sprocket assembly structure that is easy to assemble and disassemble, effectively solving the problem of quick connection between the bicycle bottom bracket, crank, and sprocket. Example

[0018] like Figure 1 - Figure 10 As shown, the technical solution in this application embodiment effectively solves the technical problem of quick connection between the bicycle bottom bracket, crank, and sprocket. The overall idea is as follows: To address the problems existing in the prior art, this utility model provides a bicycle bottom bracket, crank, and sprocket assembly structure that is easy to disassemble and assemble, including: The sprocket unit 1, the central shaft unit 2, and the crank unit 3 are provided, wherein the two ends of the central shaft unit 2 are respectively snapped with the sprocket unit 1 and the crank unit 3, and the central shaft unit 2 is characterized in that two symmetrical stabilizing components 21 and snapping components 22 are provided inside the central shaft unit 2. The stabilizing component 21 includes a stabilizing strip 211, and the two ends of the stabilizing strip 211 are symmetrically provided with blocking plugs 212; The snap-fit ​​assembly 22 is symmetrically provided with a first snap-fit ​​connector 222 and a second snap-fit ​​connector 225. The appearance of the first snap-fit ​​connector 222 and the second snap-fit ​​connector 225 are the same as their internal structure. The crank unit 3 is provided with a crank connector 31, which is adapted to the second locking connector 225. The crank connector 31 and the second locking connector 225 have the same appearance and internal structure, and the crank connector 31 and the second locking connector 225 are centrally symmetrically distributed. The sprocket unit 1 is provided with a sprocket connector 12, which is adapted to the first snap-fit ​​connector 222. The sprocket connector 12 and the first snap-fit ​​connector 222 have the same appearance and internal structure, and the sprocket connector 12 and the first snap-fit ​​connector 222 are centrally symmetrically distributed.

[0019] Furthermore, the sprocket unit 1 is also provided with a sprocket 11, which is made of alloy, and the sprocket connector 12 is fixedly connected to the center of one end of the sprocket 11.

[0020] Furthermore, the snap-fit ​​assembly 22 also includes a first adapter cap 221 and a second adapter cap 224. The appearance and internal structure of the first adapter cap 221 and the second adapter cap 224 are the same. The first adapter cap 221 and the second adapter cap 224 are arranged in a mirror symmetrical manner. One end of the first adapter cap 221 is fixedly connected to the first snap-fit ​​connector 222, and one end of the second adapter cap 224 is fixedly connected to the second snap-fit ​​connector 225. A shaft cylinder 223 is connected between the first adapter cap 221 and the second adapter cap 224. The shaft cylinder 223 is cylindrical.

[0021] Furthermore, the crank unit 3 also includes a handle 32, one end of which is fixedly connected to the crank connector 31.

[0022] Furthermore, the stabilizing strip 211 includes a square strip 2111, and the square strip 2111 has a plug hole 2112; The barrier plug 212 includes a plug head 2121, which is cylindrical. A plug strip 2122 is fixedly connected to the center of the plug head 2121. The plug strip 2122 is adapted to the plug hole 2112 and is made of rubber.

[0023] Furthermore, the sprocket connector 12, the first snap-fit ​​connector 222, the crank connector 31, and the second snap-fit ​​connector 225 have the same structure, all of which are provided with snap-fit ​​posts 01. The snap-fit ​​post 01 is a cylindrical base with a snap-fit ​​hole 02, which is a square hole. A stabilizing half-post 03 is fixedly connected to the snap-fit ​​post 01. The stabilizing half-post 03 is a semi-cylinder. A groove 04 is provided on the stabilizing half-post 03. The groove 04 is a triangular groove. A snap-fit ​​head 05 is fixedly connected to the other end of the stabilizing half-post 03. The size of the snap-fit ​​head 05 is adapted to the size of the snap-fit ​​hole 02. The square hole formed by the two symmetrical grooves 04 is adapted to the stabilizing snap-fit ​​strip 211.

[0024] in: Snap-fit ​​post 01: Made of aluminum alloy, it serves as the basic structure for components such as sprocket connector 12 and first snap-fit ​​connector 222. It has snap-fit ​​hole 02 and connects to the stable half post 03, providing a carrier for the interlocking of snap-fit ​​head 05 and snap-fit ​​hole 02, ensuring the consistency and adaptability of the connection structure. Snap hole 02: A square hole is made on snap-fit ​​post 01. It is adapted to the size of snap-fit ​​head 05 and allows the snap-fit ​​head 05 of the corresponding component to be inserted to achieve initial positioning and power transmission. It provides radial limit for snap-fit ​​structure to prevent relative rotation. Stabilizing half-column 03: Made of aluminum alloy, it is fixed on the snap-fit ​​column 01 and has a splicing groove 04. After the two stabilizing half-columns 03 are fitted together, the splicing groove 04 forms a square hole for the stabilizing clip 211 to be inserted, so as to realize the axial locking of the snap-fit ​​structure and enhance the connection stability. Slot 04: It is a triangular slot, which is opened on the stabilizing half column 03. It fits with the slot 04 of the corresponding component to form a square hole, providing an insertion channel for the stabilizing clip 211, realizing double fixation, and also serving as an assembly guide. Clip 05: A square protrusion, fixed to the end of the stable half-post 03, and adapted to the clip hole 02; it is embedded in the clip hole 02 of the corresponding component to realize the quick alignment and initial fixation of the clip component, transmit torque and ensure transmission concentricity.

[0025] Working principle: Traditional bicycle bottom bracket assembly requires wrenches, pullers, and other tools to connect the bottom bracket to the crank and chainring, which is not only time-consuming and labor-intensive, but also prone to errors due to the large number of parts involved. The installation structure provided in this utility model allows for easy connection of the bicycle bottom bracket to the crank and chainring without the need for wrenches, pullers, or other tools, saving time and effort.

[0026] In the first step, the sprocket 11 and the sprocket connector 12 are fixedly connected in this structure. The user only needs to insert the axle sleeve 223 into the bottom bracket of the bicycle, and then connect the first adapter cap 221 and the second adapter cap 224 to both ends of the axle sleeve 223 by rotating them. By fixing the first adapter cap 221 to the first snap-fit ​​connector 222, as shown... Figure 8 As shown, the user only needs to align the locking head 05 on the sprocket connector 12 with the locking hole 02 on the first locking head 222, and push the sprocket connector 12 horizontally toward the first locking head 222 until the locking head 05 on the sprocket connector 12 is completely pushed into the locking hole 02 of the first locking head 222. At this time, the locking head 05 on the first locking head 222 is also completely pushed into the locking hole 02 of the sprocket connector 12, so that the groove 04 on the sprocket connector 12 fits with the groove 04 on the first locking head 222, forming a complete square hole.

[0027] The second step involves the installer pushing the square strip 2111 into the square hole formed in the first step, so that the sprocket connector 12 and the first locking connector 222 are completely locked. After locking, the plug strip 2122 is fixedly connected to the plug head 2121. The user presses the plug head 2121 to insert the plug strip 2122, which is fixedly connected to the plug head 2121, into the plug hole 2112. By setting the area of ​​the plug head 2121 to be larger than the plug hole 2112, dust is prevented from entering the tiny gap formed by the locking strip 211 being inserted into the square hole, thus avoiding loosening and corrosion of parts caused by dust brought in during riding between the locking strip 211 and the square hole.

[0028] The third step involves fixing the handlebar 32 to the crank connector 31, aligning the locking head 05 on the crank connector 31 with the locking hole 02 on the second locking head 225, and then pushing the crank connector 31 toward the second locking head 225 until the locking head 05 on the crank connector 31 is fully inserted into the locking hole 02 of the second locking head 225. At this point, the groove 04 on the crank connector 31 and the groove 04 on the second locking head 225 are fully fitted together, forming a complete square hole. Then, the plug strip 2122 is inserted into the square hole formed by the crank connector 31 and the second locking head 225 through the plug 2121, thus completing the combination connection between the bicycle bottom bracket, crank, and sprocket 11.

[0029] Fourth step, during disassembly, first pull the blocking plug 212 out of the retaining clip 211, then push the two retaining clips 211 out of the square holes between the sprocket connector 12 and the first retaining clip 222, and between the crank connector 31 and the second retaining clip 225. This will pull the sprocket connector 12 out of the first retaining clip 222 and the crank connector 31 out of the second retaining clip 225, thus completing the connection between the bicycle bottom bracket and the crank and sprocket 11 assembly.

[0030] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A bicycle bottom bracket, crank, and sprocket assembly structure that is easy to disassemble and assemble, comprising a sprocket unit (1), a bottom bracket unit (2), and a crank unit (3), wherein the bottom bracket unit (2) is respectively snapped with the sprocket unit (1) and the crank unit (3), characterized in that, The central axis unit (2) is provided with two symmetrical stabilizing components (21) and a snap-fit ​​component (22). The stabilizing component (21) includes a stabilizing strip (211), and the two ends of the stabilizing strip (211) are symmetrically provided with blocking plugs (212). The snap-fit ​​assembly (22) is symmetrically provided with a first snap-fit ​​connector (222) and a second snap-fit ​​connector (225), and the appearance of the first snap-fit ​​connector (222) and the second snap-fit ​​connector (225) is the same as the internal structure; The crank unit (3) is provided with a crank connector (31), which is adapted to the second snap connector (225). The crank connector (31) and the second snap connector (225) have the same appearance and internal structure. The crank connector (31) and the second snap connector (225) are centrally symmetrically distributed. The sprocket unit (1) is provided with a sprocket connector (12), which is adapted to the first snap connector (222). The sprocket connector (12) and the first snap connector (222) have the same appearance and internal structure. The sprocket connector (12) and the first snap connector (222) are centrally symmetrically distributed.

2. The easily detachable bicycle bottom bracket, crank, and sprocket assembly structure as described in claim 1, characterized in that, The sprocket unit (1) is also provided with a sprocket (11), which is made of alloy, and the sprocket connector (12) is fixedly connected to the center of one end of the sprocket (11).

3. The easily detachable bicycle bottom bracket, crank, and sprocket assembly structure as described in claim 1, characterized in that, The snap-fit ​​assembly (22) further includes a first adapter cap (221) and a second adapter cap (224). The appearance of the first adapter cap (221) and the second adapter cap (224) are the same as their internal structure. The first adapter cap (221) and the second adapter cap (224) are arranged in a mirror symmetrical manner. One end of the first adapter cap (221) is fixedly connected to the first snap-fit ​​connector (222), and one end of the second adapter cap (224) is fixedly connected to the second snap-fit ​​connector (225). A shaft cylinder (223) is connected between the first adapter cap (221) and the second adapter cap (224). The shaft cylinder (223) is cylindrical.

4. The easily detachable bicycle bottom bracket, crank, and sprocket assembly structure as described in claim 1, characterized in that, The crank unit (3) also includes a handle (32), one end of which is fixedly connected to the crank connector (31).

5. The easily detachable bicycle bottom bracket, crank, and sprocket assembly structure as described in claim 1, characterized in that, The stabilizing strip (211) includes a square strip (2111), and the square strip (2111) has a plug hole (2112). The barrier plug (212) includes a plug head (2121), which is cylindrical. A plug strip (2122) is fixedly connected to the center of the plug head (2121). The plug strip (2122) is adapted to the plug hole (2112) and is made of rubber.

6. The easily detachable bicycle bottom bracket, crank, and sprocket assembly structure as described in claim 1, characterized in that... The sprocket connector (12), the first snap-fit ​​connector (222), the crank connector (31), and the second snap-fit ​​connector (225) have the same structure and are all provided with snap-fit ​​posts (01). The snap-fit ​​post (01) is a cylindrical base with a snap-fit ​​hole (02). The snap-fit ​​hole (02) is a square hole. A stabilizing half-post (03) is fixedly connected to the snap-fit ​​post (01). The stabilizing half-post (03) is a semi-cylinder. A groove (04) is provided on the stabilizing half-post (03). The groove (04) is a triangular groove. A snap-fit ​​head (05) is fixedly connected to the other end of the stabilizing half-post (03). The size of the snap-fit ​​head (05) is adapted to the size of the snap-fit ​​hole (02). The square hole formed by the two symmetrical grooves (04) is adapted to the stabilizing snap-fit ​​strip (211).

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