Gear shifting pawl assembly and speed change mechanism

Abstract

The utility model discloses a gear shifting pawl assembly and a speed change mechanism, and relates to the field of speed change devices. According to the technical scheme, the device comprises a middle shaft, a pawl, an elastic piece and a gear shifting rotating sleeve; the pawl rotates around the center line of the pawl in the pawl groove, and the rotating radius is R; when the gear shifting rotating sleeve rotates in the anticlockwise direction to close the pawl, the shortest distance between the starting point position, making contact with the pawl, of the gear shifting rotating sleeve and the center line of the pawl is L; wherein 2 < = L / R < = 2.5. According to the gear shifting pawl assembly, L and R are limited, so that the resistance borne by the gear shifting rotating sleeve when the pawl is closed is reduced, the pawl can be smoothly pressed down to be closed, the smoothness of the gear shifting process is improved, the user experience is optimized, and the size optimization of the gear shifting pawl assembly can be considered; moreover, the limiting part is matched with the axial extension groove to limit the pawl, so that the pawl cannot be driven to deviate when the gear shifting rotating sleeve rotates forwards or reversely, and the gear control precision can be improved.

Description

Technical Field

[0001] This utility model relates to the field of transmission devices, and more specifically, it relates to a shift pawl assembly and a transmission mechanism. Background Technology

[0002] In the gear shifting mechanism of a bicycle, multiple pawls are usually used to switch gears.

[0003] The existing Chinese patent with authorization announcement number CN221477422U discloses a hub motor with an integrated transmission mechanism, which includes a shift adjustment component. The shift adjustment component includes multiple pawls respectively embedded in the central shaft and a shift sleeve sleeved on the central shaft. The shift sleeve is used to control the pawls to pop up or retract.

[0004] When applying the shift adjustment component structure to different transmission mechanisms, the shape and size of parts such as the ratchet pawl need to be adjusted. However, a strong shifting jerk feeling often occurs, meaning high shifting resistance, which affects the user experience. Therefore, how to optimize the structure of the aforementioned shift adjustment component to reduce shifting resistance and shifting jerk feeling is an urgent problem to be solved. Utility Model Content

[0005] In view of the shortcomings of the existing technology, one of the objectives of this utility model is to provide a shift pawl assembly, which is beneficial to improving the smoothness and accuracy of the shifting process and optimizing the user experience.

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

[0007] A shift pawl assembly, comprising:

[0008] The central shaft is provided with a ratchet groove;

[0009] A pawl rotatably disposed in a pawl groove, the pawl having a closed state and an open state;

[0010] An elastic element acting on the pawl, the elastic force of which causes the pawl to tend to rotate to the open state; and,

[0011] A shift sleeve rotatably fitted on the central shaft, the shift sleeve being used to open or close the ratchet pawl;

[0012] The pawl rotates within the pawl groove around the pawl centerline with a rotation radius of R. The direction of rotation of the pawl from the closed state to the open state is defined as counterclockwise. Then, the shift sleeve can rotate in both counterclockwise and clockwise directions to close the pawl.

[0013] When the shift sleeve rotates counterclockwise to close the pawl, the shortest distance between the starting point of its contact with the pawl and the center line of the pawl is L.

[0014] Where 2≤L / R≤2.5.

[0015] Furthermore, the pawl is provided with a continuous surface, and the shift sleeve contacts the continuous surface during the closing of the pawl.

[0016] Furthermore, the continuous surface is an inclined surface or an arc surface.

[0017] Furthermore, the pawl includes a rotating base, a contact portion, and a pawl head connected in sequence; the contact portion is provided with a continuous surface.

[0018] Furthermore, the contact portion is provided with a first continuous surface and a second continuous surface, and the pawl head and the first continuous surface are arranged side by side along the axial direction;

[0019] The shift sleeve rotates counterclockwise and contacts the first continuous surface during the closing of the pawl; the shift sleeve rotates clockwise and contacts the second continuous surface during the closing of the pawl.

[0020] Furthermore, the sidewall of the rotating base is provided with a limiting part that protrudes axially from the sidewall of the contact part, and the inner sidewall of the ratchet groove is provided with an axially extending groove that cooperates with the limiting part.

[0021] Furthermore, the rotating base is provided with a rotating arc surface arranged around the center line of the pawl, and the radius of the rotating arc surface is R.

[0022] Another objective of this utility model is to provide a speed change mechanism, which includes the above-mentioned shift pawl assembly.

[0023] In summary, this utility model has the following beneficial effects:

[0024] 1. This utility model defines L and R, that is, when the shift sleeve rotates counterclockwise, the distance between the starting point of the shift sleeve and the pawl contact centerline is 2-2.5 times the pawl rotation radius. This helps to reduce the resistance encountered by the shift sleeve when closing the pawl, thereby enabling the pawl to be smoothly pressed down and closed, improving the smoothness of the shifting process, optimizing the user experience, and also taking into account the size optimization of the shift pawl assembly;

[0025] 2. The contact part is provided with a continuous surface. The shift sleeve contacts the continuous surface during the closing of the pawl. This helps to reduce the resistance encountered by the shift sleeve during the closing of the pawl and improve the smoothness of the shifting process.

[0026] 3. The limiting part and the axial extension groove cooperate to limit the pawl, so that the shift sleeve will not cause the pawl to deviate when rotating forward or backward, thereby improving the control accuracy of the gear. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the shift pawl assembly in Example 1. Figure 1 ;

[0028] Figure 2 This is a schematic diagram of the shift pawl assembly in Example 1. Figure 2 ;

[0029] Figure 3 This is a schematic diagram of the structure of the central shaft and the pawl in Example 1;

[0030] Figure 4 This is a schematic diagram of the pawl structure in Example 1.

[0031] In the figure: 1. Pawl; 11. Rotating base; 111. Rotating arc surface; 112. Limiting part; 12. Contact part; 121. First continuous surface; 122. Second continuous surface; 13. Pawl head; 14. Slot; 2. Central shaft; 21. Pawl groove; 22. Axial extension groove; 3. Shift sleeve; 31. Release port; 32. Pressing part; 4. Elastic element. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings.

[0033] 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:

[0034] A shift pawl assembly, as shown in the reference Figures 1 to 4 It includes a pawl 1, a central shaft 2, a shift sleeve 3, and an elastic element 4; specifically, a pawl groove 21 is provided on the central shaft 2, and the pawl 1 is rotatably disposed in the pawl groove 21, so the pawl 1 includes a closed state and an open state; the elastic element 4 acts on the pawl 1, and the elastic force of the elastic element 4 makes the pawl 1 tend to rotate to the open state; the shift sleeve 3 is rotatably sleeved on the central shaft 2, and the shift sleeve 3 is used to open or close the pawl 1; the rotation direction of the pawl 1 from the closed state to the open state is defined as counterclockwise (e.g., ...). Figure 2 As shown), the shift knob 3 can be rotated in both counterclockwise and clockwise directions to close the pawl 1.

[0035] Reference Figures 1 to 4In this embodiment, the pawl 1 rotates around the pawl centerline within the pawl groove 21 with a rotation radius of R. When the shift sleeve 3 rotates counterclockwise to close the pawl 1, the shortest distance between the starting point of its contact with the pawl 1 and the pawl centerline is L. Wherein, 2≤L / R≤2.5.

[0036] Reference Figures 1 to 4 When the shift sleeve 3 rotates counterclockwise to close the pawl 1, the pawl 1 needs to rotate clockwise to close. Therefore, the rotation direction of the shift sleeve 3 is opposite to that of the pawl 1. The resistance encountered when the shift sleeve 3 and pawl 1 first make contact is relatively large. If the pawl 1 cannot be smoothly pressed down to close, it may cause a jerking sensation during shifting, affecting the user experience. In this embodiment, L and R are limited; that is, the distance between the starting points of contact between the shift sleeve 3 and pawl 1 and the center lines of the pawl is 2-2.5 times the rotation radius of the pawl. This results in... This reduces the resistance encountered by the shift sleeve 3 when closing the pawl 1, thus enabling the pawl 1 to be smoothly pressed down and closed, improving the smoothness of the shifting process and optimizing the user experience. If L / R is less than 2, the resistance encountered by the shift sleeve 3 when closing the pawl 1 will be greater. If L / R is greater than 2.5, it will be detrimental to the size optimization of the shift pawl assembly. In other words, in this embodiment, 2≤L / R≤2.5 can reduce the resistance encountered by the shift sleeve 3 during the shifting process and improve the smoothness of the shifting, while also taking into account the size optimization of the shift pawl assembly.

[0037] Reference Figures 1 to 4 When the shift sleeve 3 rotates clockwise to close the pawl 1, the pawl 1 needs to rotate clockwise to close. In this case, the rotation direction of the shift sleeve 3 is the same as the rotation direction of the pawl 1. There is usually no problem of large resistance in this case.

[0038] Reference Figures 1 to 4In this embodiment, the pawl 1 includes a rotating base 11, a contact portion 12, and a pawl head 13 connected in sequence; that is, the rotating base 11, the contact portion 12, and the pawl head 13 are integrally formed; in addition, the pawl 1 is also provided with a groove 14 that cooperates with the elastic element 4; the bottom wall of the rotating base 11 is provided with a rotating arc surface 111 arranged around the center line of the pawl, and the radius of the rotating arc surface 111 is R; the use of the rotating arc surface 111 is beneficial to the smooth rotation of the pawl 1; wherein, the contact portion 12 is used to contact the shift sleeve 3, and the pawl head 13 is usually engaged with the sun gear in the transmission mechanism; in this embodiment, the contact portion 12 is respectively provided with the first The shift sleeve 3 has a continuous surface 121 and a second continuous surface 122. When the shift sleeve 3 rotates counterclockwise to close the pawl 1, it contacts the first continuous surface 121. When the shift sleeve 3 rotates clockwise to close the pawl 1, it contacts the second continuous surface 122. This helps to reduce the resistance encountered by the shift sleeve 3 when closing the pawl 1 and improves the smoothness of the shifting process. Specifically, if the continuous surface is an inclined surface or an arc surface, the path of contact between the shift sleeve 3 and the pawl 1 is a straight line or an arc. Preferably, the pawl head 13 and the first continuous surface 121 are arranged side by side along the axial direction, which facilitates dimensional optimization.

[0039] Reference Figures 1 to 4 The shift sleeve 3 has a release port 31, and the inner side wall of the release port 31 is provided with a pressing part 32. When the pawl 1 is opposite to the release port 31, the pawl 1 rotates under the elastic force of the elastic member 4 until it passes through the release port 31 and is in an open state. When the shift sleeve 3 rotates counterclockwise to close the pawl 1, the pressing part 32 rotates until it contacts the first continuous surface 121 on the pawl 1 until the pawl 1 is pressed down to the closed state.

[0040] Reference Figures 1 to 4 In this embodiment, the side wall of the rotating base 11 is provided with a limiting part 112 that protrudes axially from the side wall of the contact part 12, and the inner side wall of the pawl groove 21 is provided with an axially extending groove 22 that cooperates with the limiting part 112. The limiting part 112 and the axially extending groove 22 cooperate to limit the pawl 1, so that the shift sleeve 3 will not drive the pawl 1 to deviate when rotating forward or backward, thereby improving the control accuracy of the gear position. Example 2:

[0041] A speed-changing mechanism, as shown in the reference Figures 1 to 4 It includes the shift pawl assembly in Embodiment 1.

Claims

1. A shift pawl assembly, characterized in that, include: The central shaft is provided with a ratchet groove; A pawl rotatably disposed in a pawl groove, the pawl having a closed state and an open state; An elastic element acting on the pawl, the elastic force of which causes the pawl to tend to rotate to the open state; and, A shift sleeve rotatably fitted on the central shaft, the shift sleeve being used to open or close the ratchet pawl; The pawl rotates within the pawl groove around the pawl centerline with a rotation radius of R. The direction of rotation of the pawl from the closed state to the open state is defined as counterclockwise. Then, the shift sleeve can rotate in both counterclockwise and clockwise directions to close the pawl. When the shift sleeve rotates counterclockwise to close the pawl, the shortest distance between the starting point of its contact with the pawl and the center line of the pawl is L. Where 2≤L / R≤2.

5.

2. The shift pawl assembly according to claim 1, characterized in that: The pawl has a continuous surface, and the shift sleeve contacts the continuous surface during the closing of the pawl.

3. The shift pawl assembly according to claim 2, characterized in that: The continuous surface is an inclined surface or an arc surface.

4. The shift pawl assembly according to claim 2, characterized in that: The pawl includes a rotating base, a contact portion, and a pawl head connected in sequence; the contact portion is provided with a continuous surface.

5. The shift pawl assembly according to claim 4, characterized in that: The contact portion is provided with a first continuous surface and a second continuous surface, and the pawl head is arranged side by side with the first continuous surface along the axial direction; The shift sleeve rotates counterclockwise and contacts the first continuous surface during the closing of the pawl; the shift sleeve rotates clockwise and contacts the second continuous surface during the closing of the pawl.

6. The shift pawl assembly according to claim 4, characterized in that: The sidewall of the rotating base is provided with a limiting part that protrudes axially from the sidewall of the contact part, and the inner sidewall of the ratchet groove is provided with an axially extending groove that cooperates with the limiting part.

7. The shift pawl assembly according to claim 4, characterized in that: The rotating base is provided with a rotating arc surface arranged around the center line of the pawl, and the radius of the rotating arc surface is R.

8. A speed-changing mechanism, characterized in that: Includes the shift pawl assembly according to any one of claims 1-7.

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