Anti-loose type connecting structure of bicycle crankshaft

Abstract

The utility model belongs to bicycle accessory technical field, and disclose a kind of anti-loose bicycle crankshaft connecting structure, to solve the problem of inconvenient disassembly of traditional structure. The structure is based on crankshaft as basic framework, rotatable shaft center rod is equipped in crankshaft, shaft center rod both ends are connected with crank, one side is equipped with toothed disc, and the stable connection of crank and shaft center rod is realized by anti-loose connecting piece and anti-loose piece fixing bolt, anti-loose connecting piece adopts hexagonal head and tooth head coaxial design, respectively with the hexagonal groove of shaft center rod, the tooth groove of crank is matched, forms double circumferential anti-loose, in combination with the fixed bolt of axial compression, prevents the slip and relative rotation of crank. At the same time, the crank is provided with deformation gap and fastening bolt, which is convenient for assembly and can eliminate the gap, the exposed hexagonal groove is used to fix the shaft center rod during disassembly, without the cooperation of multiple tools, which greatly improves the maintenance convenience. Overall structure realizes efficient power transmission, and gives consideration to stability and maintainability, suitable for various bicycle scenes.

Description

Technical Field

[0001] This utility model relates to the field of bicycle parts technology, specifically to an anti-loosening bicycle crank bottom bracket connection structure. Background Technology

[0002] In a bicycle drivetrain, the crank-bottom bracket connection is a core load-bearing component, and its performance directly determines riding safety, power transmission efficiency, and ease of maintenance. With the diversification of riding scenarios, from daily commutes to long-distance off-road cycling, users are placing higher demands on the stability and maintainability of the crank-bottom bracket. It not only needs to ensure no slippage or relative rotation during long-term use, but also requires simplified maintenance procedures and lowered tool usage barriers.

[0003] The current mainstream bicycle crank-bottom bracket system suffers from a significant design flaw in terms of ease of disassembly. When crank disassembly and maintenance are required, the process presents considerable challenges. While a puller is typically used to separate the crank from the bottom bracket by applying axial force, allowing for easy removal of one crank, removing the remaining crank results in the bottom bracket axle losing its axial support and rotating freely (it was secured with the other crank when removing the first one). This necessitates simultaneous operation in two directions: disassembling one side while using a puller with a handle to hold the other side in place and prevent rotation. However, due to the limited space for bottom bracket installation and the restricted tool operating angle, the coordination between the wrench and puller is prone to errors, making the process extremely inconvenient. This can lead to tool slippage and damage to the bottom bracket, or even the wrench slipping out of the hand, posing a safety hazard. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a non-loosening bicycle crank bottom bracket connection structure, which solves the problems mentioned in the background art, such as the inconvenience of disassembling the remaining crank end of the existing bicycle bottom bracket.

[0005] To achieve the above-mentioned objectives, this utility model provides the following technical solution: a non-loosening bicycle crank bottom bracket connection structure, comprising: The crank bottom bracket is fixedly installed inside the bottom bracket of the bicycle, and a rotatable axle is installed inside the crank bottom bracket. The crankset is located on one side of the crank shaft and is coaxially connected to the spindle. Two sets of cranks are respectively located at both ends of the crankshaft, and both sets of cranks are coaxially connected to the shaft. Two sets of anti-loosening connectors are provided. The anti-loosening connectors are set on the end face of the shaft rod. The shaft rod and the anti-loosening connectors are provided with mating screw holes. Anti-loosening fixing bolts are provided in the mating screw holes. The crank is installed at both ends of the shaft rod through the anti-loosening connectors and anti-loosening fixing bolts.

[0006] Preferably, the crankshaft further includes a bearing cup sleeve, which is fitted onto the outer ring of the shaft rod. The bearing cup sleeve is fixedly connected to the bottom bracket, and the shaft rod is rotatably connected to the bottom bracket through the bearing cup sleeve.

[0007] Preferably, the bearing cup sleeve includes two sets of bearing components and a five-way plug rod. The five-way plug rod is disposed inside the five-way connector, and the two sets of bearing components are disposed at both ends of the five-way plug rod. The inner side of the two sets of bearing components is provided with mounting rings, which are fixedly connected to the outer rings of the bearing components. The bearing components are connected to the five-way connector through the mounting rings, and the inner rings of the bearing components are fixedly connected to the shaft rod.

[0008] Preferably, one end of the shaft is fitted with a claw, and the crank plate is provided with a crank plate inner extension block corresponding to the claw. The claw and the crank plate inner extension block are fixedly connected by bolts.

[0009] Preferably, the anti-loosening connector includes a hexagonal head and a toothed head, the size of the hexagonal head being smaller than the size of the toothed head, and the hexagonal head and the toothed head being coaxially and fixedly connected.

[0010] Preferably, the end face of the shaft rod is provided with a hexagonal groove corresponding to the hexagonal head, and the crank is provided with a toothed groove corresponding to the toothed head. The hexagonal head is engaged in the hexagonal groove, and the toothed head is engaged in the toothed groove.

[0011] Preferably, the crank has a deformation notch that communicates with the tooth groove, and vertical fastening bolts are provided on both sides of the deformation notch.

[0012] Compared with the prior art, this utility model provides a non-loosening bicycle crank bottom bracket connection structure, which has the following beneficial effects: This anti-loosening bicycle crank bottom bracket connection structure includes a crank bottom bracket, axle rod, chainring, crank, anti-loosening connector, anti-loosening bolt, chainring claw, deformation notch, and fastening bolt. It prevents crank slippage, and the crank and bottom bracket are fixed together, making relative rotation difficult. After removing the anti-loosening connector on one side, the remaining hexagonal groove can be used to fix the crank bottom bracket, facilitating the removal of the other end of the crank. Maintenance is convenient; a common Allen wrench can be used directly without the need for a puller. It is easy to use, simple, and highly practical. Attached Figure Description

[0013] 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 crankshaft and chainring structure of this utility model; Figure 4 This is a schematic diagram of the crankshaft and anti-loosening connector of this utility model.

[0014] In the diagram: 1. Crankshaft; 2. Shaft rod; 3. Chainring; 4. Crank; 5. Anti-loosening connector; 6. Mating screw hole; 7. Anti-loosening fixing bolt; 8. Bearing cup sleeve; 9. Bearing component; 10. Five-way plug rod; 11. Mounting ring; 12. Chainring claw; 13. Chainring inner extension block; 14. Hexagonal head; 15. Tooth head; 16. Hexagonal groove; 17. Tooth groove; 18. Deformation notch; 19. Fastening bolt. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1-4 This utility model provides a technical solution: A non-loosening bicycle crank bottom bracket connection structure includes: Crank shaft 1, the crank shaft 1 is fixedly installed in the bottom bracket of the bicycle, and a rotatable axle 2 is provided inside the crank shaft 1; Crank 3 is located on one side of the crank shaft 1 and is coaxially connected to the spindle 2; Two sets of cranks 4 are respectively set at both ends of the crank shaft 1, and both sets of cranks 4 are coaxially connected to the shaft rod 2; the pedals are installed at the end of the cranks 4 away from the shaft rod.

[0017] Two sets of anti-loosening connectors 5 are provided on the end face of the shaft rod 2. The shaft rod 2 and the anti-loosening connectors 5 are provided with mating screw holes 6. Anti-loosening fixing bolts 7 are provided in the mating screw holes 6. The crank 4 is installed at both ends of the shaft rod 2 through the anti-loosening connectors 5 and the anti-loosening fixing bolts 7.

[0018] Furthermore, the crank shaft 1 also includes a bearing cup sleeve 8, which is fitted on the outer ring of the shaft rod 2. The bearing cup sleeve 8 is fixedly connected to the bottom bracket, and the shaft rod 2 is rotatably connected to the bottom bracket through the bearing cup sleeve 8.

[0019] Furthermore, the bearing cup sleeve 8 includes two sets of bearing components 9 and a five-way plug rod 10. The five-way plug rod 10 is disposed inside the five-way connector, and the two sets of bearing components 9 are disposed at both ends of the five-way plug rod 10. The inner side of the two sets of bearing components 9 is provided with mounting rings 11, which are fixedly connected to the outer ring of the bearing component 9. The bearing component 9 is connected to the five-way connector through the mounting rings 11, and the inner ring of the bearing component 9 is fixedly connected to the shaft rod 2.

[0020] Furthermore, a claw 12 is sleeved on one end of the shaft rod 2, and an inner extension block 13 corresponding to the claw 12 is provided on the gear 3. The claw 12 and the inner extension block 13 are fixedly connected by bolts.

[0021] Furthermore, the anti-loosening connector 5 includes a hexagonal head 14 and a toothed head 15. The size of the hexagonal head 14 is smaller than the size of the toothed head 15, and the hexagonal head 14 and the toothed head 15 are coaxially fixedly connected.

[0022] Furthermore, the end face of the spindle 2 has a hexagonal groove 16 corresponding to the hexagonal head 14, and the crank 4 has a toothed groove 17 corresponding to the toothed head 15. The hexagonal head 14 is engaged in the hexagonal groove 16, and the toothed head 15 is engaged in the toothed groove 17. The fixed shape of the hexagonal head 14 and the hexagonal groove 16 makes it difficult for the anti-loosening connector 5 to loosen relative to the spindle 2, and the fixed shape of the toothed head 15 and the toothed groove 17 makes it difficult for the anti-loosening connector 5 to loosen relative to the crank 4. The anti-loosening connector 5 ultimately achieves an anti-loosening connection, which can meet the usage requirements of the bicycle bottom bracket.

[0023] Furthermore, the crank 4 has a deformation notch 18 that communicates with the tooth groove 17, and vertical fastening bolts 19 are provided on both sides of the deformation notch 18. The deformation notch 18 provides a gap for the anti-loosening fixing bolt 7 to facilitate material deformation. After installation, it can be tightened by screwing on the fastening bolts 19. This avoids the problem of the material being difficult to install due to excessively precise dimensions and the loosening after installation due to excessively large reserved gaps.

[0024] Structural Description: Crank shaft 1: The basic load-bearing structure of the device, fixedly installed in the bottom bracket of the bicycle, with a rotatable shaft rod 2 inside, and an integrated bearing cup sleeve 8, providing a stable mounting frame for the entire connection structure; Shaft rod 2: It has a rod-shaped structure and is set inside the crank shaft 1, which can rotate freely. Both ends are connected to the crank 4. One end is fitted with a disc claw 12, and the end face is provided with a hexagonal groove 16 and a matching screw hole 6. It is the core rod for power transmission. Chain 3: It has a disc-shaped transmission structure, is set on one side of the crank shaft 1, and is coaxially connected with the shaft rod 2. It is fixed to the chain claw 12 by the inner extension block 13 of the chain 3 and is used to transmit power to the chain. Crank 4: It has a long rod-shaped structure, with two sets respectively set at both ends of the crank shaft 1 and coaxially connected with the shaft rod 2. The end opposite to the shaft rod 2 is used to install the pedal. It has a toothed groove 17 and a deformation notch 18 communicating with the toothed groove 17. It is connected to the shaft rod 2 through the anti-loosening connector 5. Anti-loosening connector 5: It consists of a hexagonal head 14 and a toothed head 15 that are coaxially fixedly connected (the size of the hexagonal head 14 is smaller than that of the toothed head 15), and is set on the end face of the shaft rod 2 to connect the crank 4 and the shaft rod 2 to achieve circumferential anti-loosening of the two. The screw hole 6 is a circular hole structure, which is respectively opened on the shaft 2 and the anti-loosening connector 5 to provide mounting holes for the anti-loosening bolt 7 and realize the axial connection between the two. Anti-loosening fixing bolt 7: It has a standard bolt structure and is installed in the mating screw hole 6 to axially press the anti-loosening connector 5 and the shaft rod 2 together, further strengthening the connection stability of the three. Bearing cup sleeve 8: It has a sleeve-shaped structure and is fitted on the outer ring of the shaft rod 2. It is fixedly connected to the bottom bracket. It contains two sets of bearing components 9 and a bottom bracket plug rod 10, so that the shaft rod 2 can rotate stably through it and the bottom bracket. Bearing component 9: It has a ring bearing structure, with two sets respectively set at both ends of the five-way plug rod 10. The inner ring is fixedly connected to the shaft rod 2, and the outer ring is connected to the five-way plug through the mounting ring 11, which helps the shaft rod 2 to rotate flexibly. Five-way plug rod 10: It has a rod-shaped structure and is set inside the five-way connector. It is a component of the bearing cup sleeve 8. Both ends are used to install two sets of bearing components 9 and provide installation support for the bearing components 9. Mounting ring 11: It has a ring structure and is set on the inner side of the bearing component 9. It is fixedly connected to the outer ring of the bearing component 9 and is used to connect and fix the bearing component 9 to the bottom bracket to achieve the positioning of the bearing component 9. Claw 12: It has a claw-shaped structure and is sleeved on one end of the shaft rod 2. It is fixedly connected to the inner extension block 13 of the gear 3 by bolts, so that the gear 3 can rotate synchronously with the shaft rod 2. The inner extension block 13 of the crank plate is a block-shaped structure, which is set on the crank plate 3 and corresponds to the claw 12. It is fixedly connected to the claw 12 by bolts and is a transitional structure for connecting the crank plate 3 and the spindle 2. Hexagonal head 14: It has a hexagonal columnar structure and is a component of the anti-loosening connector 5. Its size is smaller than that of the tooth head 15 and it is coaxially fixed with it. It is snapped into the hexagonal groove 16 to restrict the rotation of the anti-loosening connector 5 relative to the shaft 2. Tooth head 15: It has a toothed columnar structure and is a component of the anti-loosening connector 5. It is larger than the hexagonal head 14 and is fixed coaxially with it. It is snapped into the tooth groove 17 to restrict the rotation of the anti-loosening connector 5 relative to the crank 4. Hexagonal groove 16: It has a hexagonal groove structure, which is opened on the end face of the shaft 2 and corresponds to the hexagonal head 14. It is used for the hexagonal head 14 to snap into place. When disassembling, the shaft 2 can be fixed by inserting an internal hex wrench. Tooth groove 17: It has a toothed groove structure, which is opened on the crank 4 and corresponds to the tooth head 15. It is used for the tooth head 15 to snap into place and communicates with the deformation notch 18 to realize the circumferential fixation of the crank 4 and the anti-loosening connector 5. Deformation notch 18: It has a strip-shaped notch structure, is opened on the crank 4 and communicates with the tooth groove 17, and has fastening bolts 19 on both sides to provide material deformation space for the assembly of the anti-loosening connector 5. Fastening bolt 19: It has a standard bolt structure and is set vertically on both sides of the deformation notch 18. Tightening it can reduce the gap of the deformation notch 18, so that the tooth groove 17 and the tooth head 15 mesh more tightly and eliminate the assembly gap.

[0025] Working principle: The crankshaft 1 serves as the basic load-bearing frame, achieving a stable connection with the bicycle bottom bracket via bearing cups 8. The bottom bracket plug 10 is embedded inside the bottom bracket, and the bearing components 9 at both ends are fixed to the inner wall of the bottom bracket via mounting rings 11. At the same time, the inner ring of the bearing component 9 is tightly fitted with the axle rod 2. This ensures that the axle rod 2 can rotate flexibly around its own axis, providing a stable rotational foundation for subsequent power transmission.

[0026] The chainring 3 is secured to the chainring claw 12 at one end of the axle rod 2 via the chainring inner extension block 13, ensuring no relative rotation between the chainring 3 and the axle rod 2. Two sets of cranks 4 are connected to both ends of the axle rod 2 via anti-loosening connectors 5. The pedals are mounted on the ends of the cranks 4 facing away from the axle rod. When the rider pedals, power is transmitted sequentially through the cranks 4 and anti-loosening connectors 5 to the axle rod 2, which then drives the chainring 3 to rotate, ultimately achieving efficient power transmission to the chain. The entire transmission path has no redundant gaps, effectively avoiding power loss. Furthermore, the coaxial connection design of all components ensures no eccentric vibration during transmission, improving riding comfort.

[0027] The anti-loosening connector 5 is coaxially composed of hexagonal heads 14 and toothed heads 15 of different sizes. During assembly, the hexagonal heads 14 are precisely engaged in the hexagonal grooves 16 on the end face of the shaft rod 2. Utilizing the surface contact limiting characteristics of the hexagonal structure, the rotational freedom of the anti-loosening connector 5 relative to the shaft rod 2 is completely restricted, preventing circumferential loosening caused by long-term rotation. At the same time, the toothed heads 15 and the toothed grooves 17 on the crank 4 form a tooth meshing, and through the interlocking action between the tooth surfaces, the relative rotation between the anti-loosening connector 5 and the crank 4 is blocked, forming a double circumferential fixation of the shaft rod, anti-loosening connector, and crank. In addition, the anti-loosening fixing bolts 7 pass through the mating screw holes 6 of the anti-loosening connector 5 and the shaft rod 2 to achieve axial compression, further strengthening the connection stability of the three and preventing problems such as crank slippage and relative rotation.

[0028] During installation, the deformation notch 18 provides a certain material deformation space for the crank 4, avoiding assembly difficulties caused by excessively high dimensional accuracy of the tooth head 15 and tooth groove 17; after installation, by tightening the vertical fastening bolts 19 on both sides of the deformation notch 18, the notch gap can be reduced, making the meshing of the tooth groove 17 and tooth head 15 tighter, while eliminating assembly gaps and preventing axial loosening during long-term use.

[0029] During disassembly and maintenance, the anti-loosening fixing bolts 7 and anti-loosening connectors 5 on one side must be removed first. Then, the crank on one side can be disassembled. After that, the shaft rod 2 can be easily fixed with an Allen wrench by using the exposed hexagonal groove 16 on the end face of the shaft rod 2 to prevent it from rotating freely. When disassembling the crank on the other side, there is no need to rely on the coordinated operation of puller and wrench, which greatly simplifies the operation process, lowers the threshold for tool use, and achieves efficient maintenance.

[0030] In summary, this structure, through the complementary functions and precise coordination of its components, not only ensures the stability of power transmission and the reliability of preventing loosening, but also solves the pain point of inconvenient disassembly of traditional structures, fully meeting the usage and maintenance needs of bicycles in different scenarios.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A non-loosening bicycle crank bottom bracket connection structure, characterized in that, include: Crank shaft (1) is fixedly installed in the bottom bracket of the bicycle. A rotatable axle rod (2) is provided inside the crank shaft (1). Crank (3) is located on one side of the crank shaft (1) and is coaxially connected to the shaft rod (2); Two sets of cranks (4) are respectively set at both ends of the crank shaft (1), and both sets of cranks (4) are coaxially connected to the shaft rod (2); Two sets of anti-loosening connectors (5) are provided on the end face of the shaft rod (2). The shaft rod (2) and the anti-loosening connectors (5) are provided with mating screw holes (6). Anti-loosening fixing bolts (7) are provided in the mating screw holes (6). The crank (4) is installed at both ends of the shaft rod (2) through the anti-loosening connectors (5) and the anti-loosening fixing bolts (7).

2. The anti-loosening bicycle crankshaft connection structure according to claim 1, characterized in that, The crank shaft (1) also includes a bearing cup sleeve (8), which is fitted on the outer ring of the shaft rod (2). The bearing cup sleeve (8) is fixedly connected to the bottom bracket, and the shaft rod (2) is rotatably connected to the bottom bracket through the bearing cup sleeve (8).

3. The anti-loosening bicycle crankshaft connection structure according to claim 2, characterized in that, The bearing cup sleeve (8) includes two sets of bearing components (9) and a five-way plug rod (10). The five-way plug rod (10) is located inside the five-way connector. The two sets of bearing components (9) are located at both ends of the five-way plug rod (10). The inner side of the two sets of bearing components (9) is provided with an installation ring (11). The installation ring (11) is fixedly connected to the outer ring of the bearing component (9). The bearing component (9) is connected to the five-way connector through the installation ring (11), and the inner ring of the bearing component (9) is fixedly connected to the shaft rod (2).

4. The anti-loosening bicycle crankshaft connection structure according to claim 1, characterized in that, One end of the shaft (2) is fitted with a claw (12), and the toothed plate (3) is provided with a toothed plate inner extension block (13) corresponding to the claw (12). The claw (12) and the toothed plate inner extension block (13) are fixedly connected by bolts.

5. The anti-loosening bicycle crankshaft connection structure according to claim 1, characterized in that, The anti-loosening connector (5) includes a hexagonal head (14) and a toothed head (15). The size of the hexagonal head (14) is smaller than that of the toothed head (15), and the hexagonal head (14) and the toothed head (15) are coaxially fixedly connected.

6. The anti-loosening bicycle crankshaft connection structure according to claim 5, characterized in that, The end face of the shaft rod (2) is provided with a hexagonal groove (16) corresponding to the hexagonal head (14), and the crank (4) is provided with a tooth groove (17) corresponding to the tooth head (15). The hexagonal head (14) is engaged in the hexagonal groove (16), and the tooth head (15) is engaged in the tooth groove (17).

7. The anti-loosening bicycle crankshaft connection structure according to claim 6, characterized in that, The crank (4) has a deformation notch (18) that communicates with the tooth groove (17), and vertical fastening bolts (19) are provided on both sides of the deformation notch (18).

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