Novel crank anti-loosening structure

Abstract

The utility model provides a novel crank anti -loosening structure, include: left crank, middle axle, two locking screws, lock bolt, elastic gasket, the fixed hole for locking the middle axle is set up in the connecting end of left crank, one deformation seam is equipped in the side portion of fixed hole, the connecting end of left crank is equipped with two locking screw holes through deformation seam, two locking screws are cooperated with two locking screw holes, are used for adjusting the aperture of fixed hole through deformation seam, lock bolt includes head section and stem section, and the junction of head section and stem section is equipped with annular convex, and elastic gasket is annular, and is equipped with a plurality of protruding on its inner ring wall, and elastic gasket is clamped between head section and annular convex through a plurality of protruding, and the inner wall of middle axle connecting end is equipped with the internal thread of cooperation with lock bolt stem section. The utility model has solved the problem that the loosening appears after long time riding because of too small locking force, also avoided the problem that bearing inner shell and outer shell are out of position because of too large locking force.

Description

Technical Field

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

[0002] A bicycle, also known as a pedal bike or bike, is a vehicle that uses pedals to power its wheels. It is a green and environmentally friendly means of transportation. It mainly consists of a frame, transmission, running gear, and safety devices. Among the various parts of a bicycle, apart from some small bearings, there are three main types of bearings: the front axle, the bottom bracket, and the rear axle. The front and rear axles only need to withstand bending moments and do not rotate, so they are fixed axles. The bottom bracket, on the other hand, withstands both bending moments and torque, so it is a rotating axle. The bottom bracket is the axle used to connect the pedals to the crank. Therefore, the connection between the bottom bracket and the crank can affect the user's experience of riding a bicycle.

[0003] See Figure 1 , Figure 2 ,as well as Figure 3 As shown, in the transmission structure, the left crank 10' has an open fixing hole 11' for locking the bottom shaft 20' on its connecting end. A first pressing tooth is arranged on the inner wall of the fixing hole 11', and a second pressing tooth matching the first pressing tooth is arranged on the outer wall of the connecting end of the bottom shaft 20'. This allows the left crank 10' and the bottom shaft 20' to lock together during installation. During installation, the tightening screw 3' is first inserted into the fixing hole 11' at the connecting end of the left crank 10', tightening the left crank 10' and ensuring the locking state between the left crank 10' and the bottom shaft 20'. Finally, two tightening screws 4' are alternately tightened to secure the opening of the fixing hole 11', firmly clamping the left crank 10' to the bottom shaft 20', thus ensuring the entire crankset is locked securely.

[0004] However, because the bearing 5' on the bottom bracket 20' is press-fitted into the cup 60' at its connecting end, the inner shell of the bearing 5' will be tightly pressed against the plastic side cover 7' of the cup 60'. When the tightening screw 3' is locked into the fixing hole 11' to tighten the bottom bracket 20', the connecting end of the left crank 10' will press against the plastic side cover 7', so the pressure exerted by the left crank 10' on the plastic side cover 7' will ultimately act on the inner shell of the bearing 5'. Therefore, the greater the tightening torque of the tightening screw 3', the greater the force exerted by the left crank 10' on the inner shell of the bearing 5', while the outer shell of the bearing 5' is not under pressure, which will cause misalignment between the inner and outer shells of the bearing 5', leading to jamming during riding.

[0005] While existing technologies offer solutions by replacing the material of the tightening screw 3' with plastic, thus preventing excessive tightening torque and avoiding misalignment between the inner and outer shells of the bearing, the plastic tightening screw 3' also has limitations due to its lower tightening torque, which can lead to loosening or falling off during prolonged riding. Utility Model Content

[0006] This invention was developed to solve the above-mentioned problems, and its purpose is to provide a novel crank anti-loosening structure.

[0007] This utility model provides a novel crank anti-loosening structure, comprising: a left crank, a bottom shaft, two locking screws, a locking bolt, and an elastic washer. A threaded cup is fitted onto the bottom shaft, and a bearing is press-fitted inside the threaded cup. A side cover is provided at the port of the threaded cup, and the side cover fits snugly against the inner shell of the bearing. Its distinguishing feature is:

[0008] The connecting end of the left crank has a fixing hole for locking the bottom shaft. The fixing hole is a countersunk fixing hole with adjacent small-diameter and large-diameter sections. The side of the fixing hole has an expansion joint. The connecting end of the left crank has two locking screw holes that pass through the expansion joint.

[0009] Two locking screws mate with two locking screw holes, used to adjust the diameter of the fixing holes through the expansion joint.

[0010] The locking bolt consists of a head section and a shank section. The diameter of the head section is equal to the diameter of the major diameter section, and the height of the head section is less than the depth of the major diameter section. An annular protrusion is provided at the connection between the head section and the shank section, and the diameter of the annular protrusion is smaller than the diameter of the minor diameter section.

[0011] The elastic gasket is annular, with both its top and bottom walls being wavy. Multiple protrusions are evenly distributed circumferentially towards the center of the inner ring wall. The elastic gasket is secured between the head section and the annular protrusions via these protrusions.

[0012] The inner wall of the central shaft connection end is provided with an internal thread that mates with the locking bolt rod segment.

[0013] The novel crank anti-loosening structure provided by this utility model also has the following features: the inner wall of the small diameter section is provided with a first press-fitting tooth along the circumferential direction, and the outer wall of the central shaft connection end is provided with a second press-fitting tooth along the circumferential direction to cooperate with the first press-fitting tooth. The first press-fitting tooth is composed of a first arc-shaped groove and a first arc-shaped protrusion connected in sequence on multiple side ends, and the second press-fitting tooth is composed of a second arc-shaped groove and a second arc-shaped protrusion connected in sequence on multiple side ends.

[0014] The novel crank anti-loosening structure provided by this utility model also has the following features: both locking screw holes are countersunk screw holes, the two locking screw holes are arranged in parallel along the central axis, and the central axis of the two locking screw holes is perpendicular to the radial section of the central axis. The heads of the two countersunk screw holes are respectively arranged on both sides of the width direction of the head end of the left crank.

[0015] The novel crank anti-loosening structure provided by this utility model also has the following feature: the locking bolt is made of aluminum alloy.

[0016] The novel crank anti-loosening structure provided by this utility model also has the following feature: three protrusions are provided on the inner ring wall of the elastic gasket.

[0017] Functions and effects of utility models

[0018] According to the novel crank anti-loosening structure of this utility model, when locking the left crank and bottom bracket, the annular protrusion on the locking bolt will screw into the bottom bracket along with the crank section, first abutting against the end face of the bottom bracket. Then, by increasing the locking torque, the head of the locking bolt will squeeze the elastic washer, thereby clamping the left crank tightly through the elastic washer. At this time, the force transmitted from the left crank to the bearing inner housing through the side cover is actually the elastic force of the elastic washer itself, thus avoiding the problem of misalignment between the bearing inner housing and outer housing due to excessive locking force. Finally, by reducing the diameter of the fixing hole through the two locking screws, the left crank clamps the bottom bracket, thereby ensuring that the entire crank is locked without loosening. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the left crank and the bottom bracket in the prior art;

[0020] Figure 2 This is a cross-sectional schematic diagram of the left crank and the central shaft in the prior art;

[0021] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 This is a schematic diagram of the structure of this utility model;

[0023] Figure 5 This is a cross-sectional schematic diagram of the present invention;

[0024] Figure 6 yes Figure 5 Enlarged view of point B in the image;

[0025] Figure 7 This is a schematic diagram of the structure of the locking bolt and the elastic washer in this utility model;

[0026] Figure 8This is an exploded view of the locking bolt and elastic washer in this utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1' Left crank; 11' Mounting hole; 2' Bottom shaft; 3' Tightening screw; 4' Locking screw; 5' Bearing; 6' Threaded cup;

[0029] 7' Plastic side cover.

[0030] 10. Left crank; 11. Fixing hole; 12. Locking screw hole; 20. Bottom shaft; 30. Locking screw; 40. Locking bolt; 41. Head section; 42. Bar section; 43. Annular protrusion; 50. Elastic washer; 60. Threaded cup; 70. Bearing; 80. Side cover. Detailed Implementation

[0031] To make the technical means, creative features, objectives and effects of this utility model easy to understand, the following embodiments are described in detail with reference to the accompanying drawings.

[0032] Example

[0033] Figure 4 This is a structural schematic diagram of the present invention. Figure 5 This is a cross-sectional schematic diagram of the present invention. Figure 6 yes Figure 5 Enlarged view of point B in the image. Figure 7 This is a structural schematic diagram of the locking bolt and elastic washer in this utility model. Figure 8 This is an exploded view of the locking bolt and elastic washer in this utility model.

[0034] like Figures 4 to 8 As shown, this embodiment provides a novel crank anti-loosening structure, including: a left crank 10, a bottom shaft 20, two locking screws 30, a locking bolt 40, and an elastic washer 50. A cup 60 is fitted onto the bottom shaft 20, and a bearing 70 is press-fitted inside the cup 60. A side cover 80 is provided at the port of the cup 60, and the side cover 80 fits snugly against the inner shell of the bearing 70.

[0035] like Figures 4 to 8 As shown, a fixing hole 11 for locking the central shaft 20 is provided on the connecting end of the left crank 10. The fixing hole 11 is a countersunk fixing hole 11 with adjacent small diameter section and large diameter section. A deformation groove is provided on the side of the fixing hole 11. Two locking screw holes 12 passing through the deformation groove are provided on the connecting end of the left crank 10.

[0036] Two locking screws 30 engage with two locking screw holes 12 to adjust the diameter of the fixing hole 11 through the expansion joint.

[0037] The inner wall of the connecting end of the central shaft 20 is provided with an internal thread that mates with the locking bolt rod segment 42.

[0038] In this embodiment, the inner wall of the small-diameter section is provided with first pressing teeth along the circumferential direction, and the outer wall of the connecting end of the central shaft 20 is provided with second pressing teeth along the circumferential direction to cooperate with the first pressing teeth. The first pressing teeth are composed of multiple first arc-shaped grooves and first arc-shaped protrusions connected in sequence at their side ends, and the second pressing teeth are composed of multiple second arc-shaped grooves and second arc-shaped protrusions connected in sequence at their side ends. Specifically, the first arc-shaped grooves are adapted to the second arc-shaped protrusions, and the first arc-shaped protrusions are adapted to the second arc-shaped grooves, so that after the central shaft 20 is inserted into the fixing groove, it is fixed by the cooperation of the first pressing teeth and the second pressing teeth, thus preventing relative rotation.

[0039] In this embodiment, both locking screw holes 12 are countersunk screw holes, arranged parallel to each other along the axial direction of the central shaft 20. The central shaft 20 line of the two locking screw holes 12 is perpendicular to the radial section of the central shaft 20. The heads of the two countersunk screw holes are respectively located on both sides of the width direction of the head end of the left crank 10. This allows the two locking screws 30 to apply force to the deformation joint from both sides of the left crank 10, making the deformed state of the deformation joint more stable, thereby better ensuring the effect of the left crank 10 clamping the central shaft 20.

[0040] like Figures 4 to 7 As shown, the locking bolt 40 includes a head section 41 and a shank section 42. The diameter of the locking bolt head section 41 is equal to the diameter of the major diameter section, and the height of the locking bolt head section 41 is less than the depth of the major diameter section. An annular protrusion 43 is provided at the connection between the head section 41 and the shank section 42. The diameter of the annular protrusion 43 is less than the diameter of the minor diameter section.

[0041] The elastic gasket 50 is annular, with both its top and bottom walls being wavy. Multiple protrusions are evenly distributed on the inner ring wall of the elastic gasket 50 in the direction of its center and along the circumference. The elastic gasket 50 is secured between the head section 41 and the annular protrusions 43 by the multiple protrusions.

[0042] In this embodiment, the locking bolt 40 is preferably an aluminum alloy bolt, and the elastic washer 50 is preferably a rubber washer.

[0043] In this embodiment, the inner ring wall of the elastic gasket 50 is preferably provided with three protrusions.

[0044] In this embodiment, the distance between the annular protrusion 43 and the top wall of the locking bolt head section 41 is equal to the distance between the end face of the central shaft 20 and the large diameter section opening of the fixing hole 11.

[0045] The assembly process of this utility model is as follows:

[0046] First, insert the connecting end of the central shaft 20 into the fixing hole 11 of the connecting end of the left crank 10. At this time, the first press-fit teeth on the inner wall of the small diameter section of the fixing hole will cooperate with the second press-fit teeth on the outer wall of the central shaft 20 to achieve initial fixation of the central shaft 20 and prevent relative rotation.

[0047] Then the elastic washer 50 is installed on the locking bolt 40 (because the elastic washer 50 can be engaged between the head section 41 of the locking bolt and the annular protrusion 43 through its protrusion, the elastic washer 50 and the locking bolt 40 can be made into one accessory during production, thus this step can be omitted).

[0048] Next, the locking bolt 40 can be screwed into the fixing hole 11 of the connecting section of the left crank 10. At this time, because the inner wall of the central shaft 20 has an internal thread that mates with the shank of the locking bolt 40, the locking bolt 40 will connect with the central shaft 20. As the shank of the locking bolt 40 penetrates deeper into the central shaft 20, the annular protrusion 43 on the locking bolt 40 will abut against the end face of the central shaft 20. At this time, the locking torque can be increased. Because the locking bolt 40 in this invention is preferably made of aluminum alloy, the locking torque can reach 40 N·m, thus ensuring the locking effect. Furthermore, because the height of the head section 41 of the locking bolt is less than the depth of the large diameter section, there will still be a gap between the head section 41 of the locking bolt 40 and the bottom wall of the large diameter section. The elastic washer located in the gap will use its own elasticity to press against the left crank 10, ensuring that the left crank 10 is in a tightened state. Simultaneously, this ensures that the force exerted by the left crank 10 on the inner shell of the bearing 70 through the side cover 80 is actually the elastic force of the elastic washer 50 itself. The elastic force of the elastic washer 50 can be adjusted according to actual usage needs; in this embodiment, the elastic force of the elastic washer 50 is approximately 15 kgf. This ensures that the left crank 10 is just properly tightened without causing misalignment of the inner shell of the bearing 70 due to excessive force. This solves the problem of loosening after prolonged riding due to insufficient tightening force of the locking bolt 40, while also preventing misalignment between the inner and outer shells of the bearing 70 due to excessive tightening force of the locking bolt 40.

[0049] Finally, the two locking screws 30 are passed through the expansion joint and engaged with the corresponding locking screw holes 12, making the diameter of the fixing hole 11 smaller, thereby clamping the left crank 10 to the bottom shaft 20, thus ensuring that the entire chainring is locked without loosening.

[0050] The role and effect of the embodiments

[0051] According to the novel crank anti-loosening structure of this utility model, when locking the left crank and bottom bracket, the annular protrusion on the locking bolt will screw into the bottom bracket along with the crank section, first abutting against the end face of the bottom bracket. Then, by increasing the locking torque, the head of the locking bolt will squeeze the elastic washer, thereby clamping the left crank tightly through the elastic washer. At this time, the force transmitted from the left crank to the bearing inner housing through the side cover is actually the elastic force of the elastic washer itself, thus avoiding the problem of misalignment between the bearing inner housing and outer housing due to excessive locking force. Finally, by reducing the diameter of the fixing hole through the two locking screws, the left crank clamps the bottom bracket, thereby ensuring that the entire crank is locked without loosening.

[0052] The above embodiments are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model.

Claims

1. A novel crank anti-loosening structure, comprising: The system comprises a left crank, a bottom bracket, two locking screws, a locking bolt, and a spring washer. A threaded cup is fitted onto the bottom bracket, and a bearing is press-fitted into the inside of the threaded cup. A side cover is provided at the port of the threaded cup, and the side cover fits snugly against the inner shell of the bearing. Its distinguishing feature is that: The connecting end of the left crank has a fixing hole for locking the bottom shaft. The fixing hole is a countersunk fixing hole with adjacent small-diameter and large-diameter sections. The side of the fixing hole has an expansion joint. The connecting end of the left crank has two locking screw holes that pass through the expansion joint. The two locking screws mate with the two locking screw holes, and are used to adjust the diameter of the fixing hole through the expansion joint. The locking bolt includes a head section and a shank section. The diameter of the head section is equal to the diameter of the major diameter section, and the height of the head section is less than the depth of the major diameter section. An annular protrusion is provided at the connection between the head section and the shank section, and the diameter of the annular protrusion is less than the diameter of the minor diameter section. The elastic gasket is annular, with both its top and bottom walls being wavy. Multiple protrusions are evenly distributed circumferentially towards the center of the inner ring wall of the elastic gasket. The elastic gasket is secured between the head section and the annular protrusions via these protrusions. The inner wall of the central shaft connection end is provided with an internal thread that mates with the locking bolt segment.

2. The novel crank anti-loosening structure according to claim 1, characterized in that: in, The inner wall of the small diameter section is provided with a first press-fitting tooth along the circumferential direction, and the outer wall of the central shaft connecting end is provided with a second press-fitting tooth along the circumferential direction to cooperate with the first press-fitting tooth. The first press-fitting tooth is composed of a first arc-shaped groove and a first arc-shaped protrusion connected in sequence on multiple side ends, and the second press-fitting tooth is composed of a second arc-shaped groove and a second arc-shaped protrusion connected in sequence on multiple side ends.

3. The novel crank anti-loosening structure according to claim 1, characterized in that: in, Both locking screw holes are countersunk screw holes, and the two locking screw holes are arranged side by side and parallel along the central axis of the central shaft. The central axis of the two locking screw holes is perpendicular to the radial section of the central shaft. The heads of the two countersunk screw holes are respectively arranged on both sides of the width direction of the head end of the left crank.

4. The novel crank anti-loosening structure according to claim 1, characterized in that: in, The locking bolt is made of aluminum alloy.

5. The novel crank anti-loosening structure according to claim 1, characterized in that: in, The elastic gasket has three protrusions on its inner ring wall.

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