Middle shaft and transmission mechanism

Abstract

The utility model discloses a center shaft and a transmission mechanism, and relates to the field of riding vehicles. According to the technical scheme, the center shaft is characterized by comprising a center shaft body, installation sections arranged at the two ends of the center shaft body respectively and locking parts arranged at the ends of the installation sections; the installation section is provided with a plurality of clamping grooves arranged in the circumferential direction, and a first clamping tooth is formed between every two adjacent clamping grooves. The clamping groove extends in the direction of a first straight line, and a first included angle is formed between the first straight line and the center line of the center shaft. A first clamping face is formed on the outer surface of the first clamping tooth and extends in the direction of a second straight line, and a second included angle is formed between the second straight line and the center line of the center shaft. The first included angle is larger than the second included angle. Through differential angle design, the connecting strength and tightness between the middle shaft and the crank can be effectively improved, looseness is effectively avoided, and safety is improved.

Description

Technical Field

[0001] This utility model relates to the field of cycling vehicles, and more specifically, it relates to a central shaft and transmission mechanism. Background Technology

[0002] With the booming development of the electric bicycle and bicycle market, especially the rapid expansion of the shared bicycle sector, the bottom bracket, as a key drive component, has become increasingly important. People propel the vehicle forward by pedaling the crank on the bottom bracket; therefore, the strength of the bottom bracket and its fit with the crank have become core elements to ensure the stability and reliability of the entire vehicle's performance.

[0003] In actual use, vehicles often face various impacts and shocks, which can cause significant damage to the crankshaft and bottom shaft.

[0004] Currently, the mounting section on the bottom bracket that mates with the crankshaft is usually square, or has a keyway. However, these mating structures are prone to loosening after the vehicle has undergone various impacts and shocks, affecting the vehicle's safety and service life. Utility Model Content

[0005] In view of the shortcomings of the existing technology, one of the purposes of this utility model is to provide a bottom shaft that, through the design of the groove, the clamping surface and the differentiated angle on the mounting section, can effectively improve the strength and tightness of the connection between the bottom shaft and the crank, and effectively prevent loosening and improve safety.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A central shaft includes a central shaft body, mounting sections respectively disposed at both ends of the central shaft body, and a locking part disposed at the end of the mounting section; the mounting section is provided with a plurality of circumferentially arranged slots, and a first locking tooth is formed between two adjacent slots;

[0008] The slot extends along a first straight line, and the first straight line forms a first angle with the center line of the central axis;

[0009] The outer surface of the first tooth is formed with a first clamping surface, which extends along a second straight line and forms a second angle with the center line of the central axis.

[0010] The first included angle is greater than the second included angle.

[0011] Furthermore, the first included angle is greater than or equal to 0.5° and less than or equal to 1.5°.

[0012] Furthermore, the second included angle is greater than 0° and less than or equal to 1.5°.

[0013] Furthermore, the first included angle is 1°, and the second included angle is 0.5°.

[0014] Furthermore, the inner wall of the slot is an arc surface.

[0015] Furthermore, the locking part includes a threaded locking section extending from the end of the mounting section; or, the locking part includes a threaded locking hole formed at the end of the mounting section.

[0016] Furthermore, the bottom bracket is adapted to a frame bottom bracket with an internal thread of BC1.37×24T or M35; or, the bottom bracket is adapted to a frame bottom bracket with an inner diameter of D30~40mm.

[0017] Another objective of this utility model is to provide a transmission mechanism, which includes the aforementioned central shaft and a crank that cooperates with the central shaft.

[0018] Furthermore, the crank is provided with a mounting hole that mates with the mounting section; the inner wall of the mounting hole is provided with a second locking surface that mates with the first locking surface, and a second locking tooth that mates with the locking groove is formed between two adjacent second locking surfaces.

[0019] Furthermore, the second clamping surface extends along the second straight line direction, and the sidewall of the second clamping tooth extends along the first straight line direction.

[0020] In summary, this utility model has the following beneficial effects:

[0021] 1. The setting of the first included angle and the second included angle can improve the tightness of the crank after installation and prevent loosening; the first included angle is larger than the second included angle, and the differentiated angle design can further improve the tightness of the connection and effectively prevent loosening after impact, thereby improving safety and service life.

[0022] 2. The inner wall of the slot is an arc surface, which helps to increase the mating surface and improve the structural strength and reliability of the connection. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the central axis structure in Example 1. Figure 1 ;

[0024] Figure 2 This is a schematic diagram of the central axis structure in Example 1. Figure 2 ;

[0025] Figure 3 This is a schematic diagram of the central axis structure in Example 1. Figure 3 ;

[0026] Figure 4 This is a schematic diagram of the transmission mechanism in Example 2;

[0027] Figure 5 This is a schematic diagram of the crank structure in Example 2;

[0028] Figure 6 This is a schematic diagram of the central axis structure in Example 3;

[0029] Figure 7 This is a schematic diagram of the transmission mechanism in Example 4.

[0030] In the diagram: 1. Main body of the central shaft; 2. Mounting section; 21. Slot; 22. First locking tooth; 23. First clamping surface; 31. Threaded locking section; 32. Threaded locking hole; 4. Crank; 41. Second clamping surface; 42. Second locking tooth; 51. Locking nut; 52. Locking bolt; 6. Central shaft accessories. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law. Example 1:

[0033] A central axis, reference Figures 1 to 3 It includes a central shaft body 1, mounting sections 2 respectively disposed at both ends of the central shaft body 1, and a locking part disposed at the end of the mounting section 2; specifically, in this embodiment, the locking part is a threaded locking section 31 extending from the end of the mounting section 2; in this embodiment, the mounting section 2 is provided with a plurality of circumferentially distributed slots 21, and a first locking tooth 22 is formed between two adjacent slots 21; specifically, in this embodiment, the inner wall of the slot 21 is an arc surface, which is beneficial to increase the mating surface and improve the structural strength and reliability of the connection.

[0034] Reference Figures 1 to 3 In this embodiment, the slot 21 extends along the first straight line direction, and the first straight line forms a first angle with the center line of the central axis; the outer surface of the first tooth 22 is formed with a first clamping surface 23, the first clamping surface 23 extends along the second straight line direction, and the second straight line forms a second angle with the center line of the central axis; wherein, the first angle is greater than the second angle.

[0035] Reference Figures 1 to 3The first included angle is formed, which is equivalent to multiple slots 21 arranged in a cone shape around the center line of the central axis; the second included angle is formed, which is equivalent to multiple first clamping surfaces 23 arranged in a cone shape around the center line of the central axis; that is, the setting of the first included angle and the second included angle can improve the tightness after installation and prevent loosening; the first included angle is larger than the second included angle, and the differentiated angle design can further improve the tightness of the connection, and can also effectively prevent loosening after being impacted, thereby improving safety and service life.

[0036] Reference Figures 1 to 3 Preferably, the first included angle is greater than or equal to 0.5° and less than or equal to 1.5°; the second included angle is greater than 0° and less than or equal to 1.5°; specifically, in this embodiment, the first included angle is 1° and the second included angle is 0.5°.

[0037] Reference Figures 1 to 3 In this embodiment, the bottom bracket is adapted to a frame bottom bracket with an internal thread of BC1.37×24T or M35; or, it is adapted to a frame bottom bracket with an inner diameter of D30~40mm. Example 2:

[0038] A transmission mechanism, as shown in the reference Figures 1 to 5 It includes the bottom bracket as in Embodiment 1, as well as the crank 4 and the locking nut 51; wherein, the crank 4 has a mounting hole that mates with the mounting section 2, the crank 4 is sleeved on the mounting section 2, and then the locking nut 51 is tightened on the threaded locking section 31 to achieve a fixed connection between the crank 4 and the bottom bracket; in this embodiment, the bottom bracket is also sleeved with a bottom bracket accessory 6, which includes a bottom bracket wrist assembly or a sensor; wherein, when the transmission mechanism is used for a power-assisted bicycle, the bottom bracket accessory 6 is preferably a sensor.

[0039] Reference Figures 1 to 5 Specifically, the inner wall of the mounting hole is provided with a second locking surface 41 that mates with the first locking surface 23, and a second locking tooth 42 that mates with the locking groove 21 is formed between two adjacent second locking surfaces 41; wherein, the second locking surface 41 extends along the second straight line direction, so as to be able to fit tightly with the first locking surface 23; the side wall of the second locking tooth 42 extends along the first straight line direction, so as to be able to fit tightly with the locking groove 21; therefore, the setting of the first included angle and the second included angle can effectively improve the strength and tightness of the connection between the mounting section 2 and the crank 4, and effectively prevent loosening, thereby improving safety. Example 3:

[0040] A central axis, reference Figures 1 to 3 as well as Figure 6 Based on Example 1, the difference between this example and Example 1 is that the locking part in this example is a threaded locking hole 32 opened at the end of the mounting section 2. Example 4:

[0041] A transmission mechanism, as shown in the reference Figures 1 to 7 It includes the central shaft in embodiment 3, as well as the crank 4 and the locking bolt 52; wherein, the crank 4 is provided with a mounting hole that mates with the mounting section 2, the crank 4 is sleeved on the mounting section 2, and then the locking bolt 52 is tightened in the threaded locking hole 32 to achieve a fixed connection between the crank 4 and the central shaft.

[0042] Reference Figures 1 to 7 Specifically, the inner wall of the mounting hole is provided with a second locking surface 41 that mates with the first locking surface 23, and a second locking tooth 42 that mates with the locking groove 21 is formed between two adjacent second locking surfaces 41; wherein, the second locking surface 41 extends along the second straight line direction, so as to be able to fit tightly with the first locking surface 23; the side wall of the second locking tooth 42 extends along the first straight line direction, so as to be able to fit tightly with the locking groove 21; therefore, the setting of the first included angle and the second included angle can effectively improve the strength and tightness of the connection between the mounting section 2 and the crank 4, and effectively prevent loosening, thereby improving safety.

Claims

1. A kingpin, characterized by: The middle shaft comprises a middle shaft body, mounting segments arranged at both ends of the middle shaft body, and locking portions arranged at the ends of the mounting segments; a plurality of clamping grooves are arranged on the mounting segments in a circumferential direction, and a first clamping tooth is formed between two adjacent clamping grooves; The clamping grooves extend along a first straight line direction, and a first included angle is formed between the first straight line and the center line of the middle shaft; A first clamping surface is formed on the outer surface of the first clamping tooth, the first clamping surface extends along a second straight line direction, and a second included angle is formed between the second straight line and the center line of the middle shaft; The first included angle is greater than the second included angle.

2. The center shaft of claim 1, wherein: The first included angle is greater than or equal to 0.5° and less than or equal to 1.5°.

3. The center shaft of claim 1, wherein: The second included angle is greater than 0° and less than or equal to 1.5°.

4. The center shaft of claim 1, wherein: The first included angle is 1°, and the second included angle is 0.5°.

5. The center shaft of claim 1, wherein: The inner wall of the clamping groove is a circular arc surface.

6. The center shaft of claim 1, wherein: The locking portion comprises a threaded locking segment extending from the end of the mounting segment; or the locking portion comprises a threaded locking hole formed in the end of the mounting segment.

7. The center shaft of claim 1, wherein: The middle shaft is adapted to a frame five-way pipe with an internal thread of BC1.37×24T or M35; or the middle shaft is adapted to a frame five-way pipe with an internal hole diameter of D30-40mm.

8. A transmission mechanism characterised in that: The middle shaft according to any one of claims 1-7, further comprising a crank matched with the middle shaft.

9. The transmission mechanism of claim 8, wherein: An installation hole is formed in the crank and matched with the mounting segment; a second clamping surface matched with the first clamping surface is arranged on the inner side wall of the installation hole, and a second clamping tooth matched with the clamping groove is formed between two adjacent second clamping surfaces.

10. The transmission mechanism of claim 9, wherein: The second clamping surface extends along the second straight line direction, and the side wall of the second clamping tooth extends along the first straight line direction.

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