Anti-loosening shift gear seat for shift shaft and motorcycle

Abstract

This utility model discloses an anti-loosening shift gear seat for a shift shaft and a motorcycle. The internal spline teeth of the shift shaft hole of the shift gear seat extend to the transition between the outer opening and the shift shaft hole, increasing the opening range of the internal spline teeth. At the same time, the internal spline teeth are opened at the location where the fastening force is concentrated, improving the distribution of fastening force on the concentrated side of the shift gear seat. This ensures sufficient clamping force while redistributing the torque transmitted from the shift shaft to the shift shaft hole, avoiding impact wear caused by rotational clearance, reducing slippage of the shift shaft relative to the shift gear seat due to wear, and solving the problem of axial loosening of the shift shaft due to wear during operation after the shift gear seat and the motorcycle's shift shaft are assembled, thus extending the service life of the shift gear seat.

Description

Technical Field

[0001] This utility model relates to the field of motorcycle structural design technology, and in particular to an anti-loosening shift gear seat for a shift shaft and a motorcycle. Background Technology

[0002] Motorcycles primarily use the shift shaft to input torque to drive the shift forks within the gearbox for shifting gears. The assembly and connection between the shift gear seat and the shift shaft is a crucial component of the shifting mechanism. Existing assembly methods for the shift gear seat and shift shaft generally involve pre-tightening with bolts and adding an opening to the shift gear seat for pre-tightening and preventing loosening. The opening is used to increase deformation and pressure. This design structure is relatively simple and has a certain anti-loosening effect.

[0003] In existing technology, the internal splines of the shift gear holder are all located in the middle of the shift shaft hole, with the area near the opening smoothed out. This results in an unreasonable arrangement of the internal splines within the shift gear holder relative to the torque distribution. In this structure, the opening is bolted in, so the force is greatest at the opening. The smoothed area at this point leads to concentrated stress on critical locations where internal splines are not present during operation, making slippage easy and causing unreasonable wear on the pressure-concentrated side. Furthermore, unreasonable wear can also occur depending on the stiffness of the shift gear holder. For example, under the same preload, if the shift gear holder stiffness is too high, it will deform less, resulting in insufficient clamping force on the shift shaft. Under external load, this can easily lead to significant local slippage, causing wear on the inner side of the shift arm. If the shift gear holder stiffness is too low, although the clamping force on the shift shaft increases, the limited range of the internal splines due to stiffness issues means they cannot adequately resist slippage. Even minor slippage can cause significant wear, affecting the normal use of the motorcycle and threatening the safety of consumers.

[0004] Therefore, it is necessary to improve the existing motorcycle shifting structure, reduce the wear and slippage of the shift gear seat while ensuring the fastening pressure and clamping force, improve the pressure distribution on the pressure concentration side of the shift gear seat, ensure uniform clamping force, and solve the problem of shift shaft loosening. Utility Model Content

[0005] In view of the shortcomings of the current motorcycle shifting structure, the purpose of this utility model is to provide an anti-loosening shifting gear seat for the shifting shaft and a motorcycle, which reduces the wear and slippage of the shifting gear seat, improves the pressure distribution on the pressure concentration side of the shifting gear seat, ensures uniform clamping force, and solves the problem of shifting shaft loosening under the condition of ensuring fastening pressure and clamping force.

[0006] To achieve the purpose of this utility model, this utility model provides an anti-loosening shift gear seat for a shift shaft. The shift gear seat has a shift shaft hole with an outer opening. The shift shaft hole has internal splines for cooperating with the shift shaft of a motorcycle. The internal splines include upper internal splines and lower internal splines. The upper internal spline extends to the transition between the shift shaft hole and the upper sidewall of the outer opening, or / and the lower internal spline extends to the transition between the shift shaft hole and the lower sidewall of the outer opening.

[0007] Furthermore, an inner opening is provided on the other side of the shift gear seat, which corresponds to the outer opening in the radial direction of the shift shaft hole.

[0008] Furthermore, the opening range of the upper internal spline extends to the transition between the shift shaft hole and the upper sidewall of the inner opening.

[0009] Furthermore, the opening range of the lower internal spline extends to the transition between the shift shaft hole and the lower sidewall of the inner opening.

[0010] Furthermore, the inner opening is a rectangular opening or an arc-shaped opening.

[0011] Furthermore, the inner opening and the outer opening are directly opposite each other in the radial direction of the shift shaft hole.

[0012] Furthermore, the ratio between the depth h of the inner opening and the root circle diameter d of the shift shaft hole is 1:3-1:4.

[0013] Furthermore, the ratio between the width l of the inner opening and the root circle diameter d of the shift shaft hole is 1:4-1:5.

[0014] Furthermore, the two side walls of the outer opening are provided with through bolt holes, which are as close as possible to the shift shaft hole.

[0015] The motorcycle of this utility model includes the aforementioned anti-loosening shift gear seat for the shift shaft.

[0016] The beneficial effects of this utility model are as follows: This utility model provides an anti-loosening shift gear seat for a shift shaft and a motorcycle. The internal spline teeth of the shift shaft hole of the shift gear seat extend to the transition between the outer opening and the shift shaft hole, increasing the opening range of the internal spline teeth. At the same time, the internal spline teeth are opened at the location where the fastening force is concentrated, improving the distribution of fastening force on the concentrated side of the shift gear seat. This ensures sufficient clamping force while redistributing the torque transmitted from the shift shaft to the shift shaft hole, avoiding impact wear caused by rotational clearance, reducing slippage of the shift shaft relative to the shift gear seat due to wear, and also solving the problem of axial loosening of the shift shaft due to wear during operation after the shift gear seat and the motorcycle shift shaft are assembled, thus extending the service life of the shift gear seat. Attached Figure Description

[0017] Figure 1 This is a top view of the anti-loosening shift gear seat for the shift shaft according to this utility model;

[0018] Figure 2 A side view of the anti-loosening shift gear seat used for the shift shaft;

[0019] Figure 3 A side view of the anti-loosening shift gear seat used for the shift shaft;

[0020] Figure 4 for Figure 3 Longitudinal cross section along the middle AA.

[0021] Explanation of reference numerals in the attached drawings: 1. Shift gear seat; 2. Shift shaft hole; 3. Outer opening; 301. Upper sidewall of the outer opening; 302. Lower sidewall of the outer opening; 4. Internal spline; 401. Upper internal spline; 402. Lower internal spline; 5. Inner opening; 501. Upper sidewall of the inner opening; 502. Lower sidewall of the inner opening; 6. Bolt hole. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in further detail below.

[0023] This utility model discloses an anti-loosening shift gear seat for a shift shaft. The shift gear seat 1 has a shift shaft hole 2, the shift shaft hole 2 has an outer opening 3, and the shift shaft hole 2 has an internal spline 4 for cooperating with the shift shaft of a motorcycle. The internal spline 4 includes an upper internal spline 401 and a lower internal spline 402. The outer opening 3 is mainly used to deform under external force so that the shift shaft hole 2 forms a clamping force on the shift shaft. Of course, the shift shaft also needs to be provided with corresponding external spline teeth to cooperate with the internal spline 4. This is an existing shift shaft installation structure and will not be described in detail here.

[0024] The opening range of the upper internal spline 401 extends to the transition between the shift shaft hole 2 and the upper sidewall 301 of the outer opening 3, and / or the opening range of the lower internal spline 402 extends to the transition between the shift shaft hole 2 and the lower sidewall 302 of the outer opening 3. The opening range of the upper internal spline 401 can be extended solely to the transition between the shift shaft hole 2 and the upper sidewall 301 of the outer opening 3, or the opening range of the lower internal spline 402 can be extended solely to the transition between the shift shaft hole 2 and the lower sidewall 302 of the outer opening 3; both can achieve certain effects. Of course, the structure where both extend to the corresponding transition is optimal; therefore, this embodiment adopts the latter.

[0025] The upper internal spline 401 and the lower internal spline 402 extend to the transition point between the upper sidewall 301 of the shift shaft hole 2 and the outer sidewall 3 of the outer opening 3, and the transition point between the lower sidewall 302 of the shift shaft hole 2 and the outer opening 3, respectively. This means that the internal spline 4 has a wider range of contact with the motorcycle's shift shaft, and can form a tighter wrap around the shift shaft from both the top and bottom. This design can significantly reduce the relative wobble between the shift shaft and the shift gear seat 1, reduce the risk of loosening due to long-term use or vibration, and also increase the contact between the shift shaft and the shift gear seat 1. The area and stress distribution are more uniform, effectively transmitting torque during gear shifting, reducing power loss, improving connection stability, avoiding jamming and disengagement during gear shifting, ensuring smooth and accurate gear shifting operation, and improving driving safety. Due to the tighter spline fit and more reasonable stress distribution, wear, impact and fatigue damage between the gear shift shaft and gear shift seat 1 are reduced, the anti-loosening effect is enhanced, the additional mechanical damage caused by loosening is reduced, the service life of gear shift seat 1 and gear shift shaft is extended, the frequency of maintenance and replacement is reduced, and the operating cost is reduced, which will not be elaborated further here.

[0026] In this embodiment, an inner opening 5 is provided on the other side of the shift gear seat 1, corresponding to the outer opening 3 in the radial direction of the shift shaft hole 2. The outer opening 3 and the inner opening 5 form a symmetrical or asymmetrical double-opening structure, which can change the stress distribution around the shift shaft hole 2. Under the conditions of torque transmission by the shift shaft and bolt tightening force, the double-opening structure can guide the stress to be reasonably dispersed to the areas of the outer opening 3 and the inner opening 5, avoiding stress concentration on a single opening side, reducing the risk of cracks and deformation at the edge of the shift shaft hole 2 due to stress concentration, improving the overall structural strength and fatigue resistance of the shift gear seat 1, and extending its service life. The double opening provides the shift shaft hole 2 with a certain elastic deformation space, which is beneficial for assembly and replacement. When the shift shaft is engaged, the shift shaft hole 2 can be slightly elastically expanded to fit the shift shaft more smoothly. After assembly, the elastic restoring force of the double-opening structure can form a more uniform clamping force on the shift shaft, strengthening the tightness of the spline fit between the shift shaft and the shift gear seat 1, further reducing the fit clearance, improving the accuracy of shift power transmission, and at the same time helping to enhance the anti-loosening effect and suppress the relative movement between the shift shaft and the shift gear seat 1 during shifting. The inner opening 5 can serve as an auxiliary guide structure during assembly, making it convenient for operators to observe and align the spline between the shift shaft and the shift shaft hole 2 from both sides. The double-opening structure can provide more operating angles and adjustment margins, reduce assembly difficulty, and improve assembly efficiency and accuracy. Further details are omitted here.

[0027] In this embodiment, the opening range of the upper internal spline 401 extends to the transition between the shift shaft hole 2 and the upper sidewall 501 of the inner opening 5. The upper internal spline 401 extending to the edge of the inner opening 5 can expand the contact range with the shift shaft, forming a more comprehensive wrap, reducing the radial wobble space of the shift shaft, and also sharing the torque load during shifting, avoiding stress concentration on the internal spline 4 near the outer opening 3, reducing the risk of local wear or fatigue fracture, and extending the service life of the shift gear seat 1. Of course, the opening range of the upper internal spline 401 may not extend to the transition between the shift shaft hole 2 and the upper sidewall 501 of the inner opening 5. The impact on the local deformation of the inner opening 5 can be ignored, but the fixing effect on the shift shaft is not as good as extending to the transition. This will not be elaborated further here.

[0028] In this embodiment, the lower internal spline 402 extends to the transition between the shift shaft hole 2 and the lower sidewall 502 of the inner opening 5. The lower internal spline 402 extending to the edge of the inner opening 5 can expand the contact range with the shift shaft, forming a more comprehensive enclosure, reducing the radial wobble space of the shift shaft, and also sharing the torque load during shifting. This avoids stress concentration on the internal spline 4 near the outer opening 3, reducing the risk of local wear or fatigue fracture, and extending the service life of the shift gear seat 1. Of course, the lower internal spline 402 may not extend to the transition between the shift shaft hole 2 and the lower sidewall 502 of the inner opening 5. The impact on the local deformation of the inner opening 5 is negligible, but the fixing effect on the shift shaft is not as good as extending to the transition. This will not be elaborated further here.

[0029] In this embodiment, the inner opening 5 is a rectangular opening or an arc-shaped opening. If the inner opening 5 is a rectangular opening, the edges are straight and the structural rigidity is more uniform. When subjected to the torsional force of the shift shaft, the right-angled side of the rectangular opening can form a clear stress dispersion boundary, making the elastic deformation range of the shift shaft hole 2 more controllable. If the inner opening 5 is an arc-shaped opening, the arc transition can avoid the local stress concentration caused by the right angle. Under the impact load of frequent shifting, the arc edge can guide the stress diffusion more smoothly and reduce the risk of cracking at the opening. This will not be elaborated further here.

[0030] In this embodiment, the inner opening 5 and the outer opening 3 are directly opposite each other in the radial direction of the shift shaft hole 2, forming a symmetrical through-hole layout. This ensures that the structural shape of the shift shaft hole 2 is consistent on both radial sides. When the bolt is tightened on the outer opening 3, the shrinkage deformation of the shift shaft hole 2 will be more uniform due to the presence of the symmetrical openings. That is, both openings provide elastic deformation space simultaneously, avoiding the shift shaft hole 2 from tilting to one side due to a single-sided opening. This ensures that the meshing clearance between the internal spline 4 and the shift shaft is evenly distributed in the circumferential direction, reducing local stress concentration and improving the overall performance. For fatigue resistance, there is usually a certain tolerance in the machining of the shift shaft and the shift shaft hole 2. The symmetrical opening design can make the elastic expansion or contraction capacity of the shift shaft hole 2 on both sides of the radial direction more balanced. When the size of the shift shaft is slightly larger or smaller, the openings on both sides can provide deformation allowance simultaneously, ensuring that the shift shaft can be installed smoothly and the clamping force is uniform after assembly. This avoids the problem of being too loose or too tight due to the limited deformation of one side opening, and improves the adaptability to parts. Of course, the width and height of the inner opening 5 and the outer opening 3 may not be consistent. The impact on the balance of the elastic expansion or contraction capacity of the shift shaft hole 2 on both sides of the radial direction is negligible and will not be elaborated here.

[0031] In this embodiment, the ratio between the depth h of the inner opening 5 and the root circle diameter d of the shift shaft hole 2 is 1:3-1:4. The depth h of the inner opening 5 directly determines the effective range of elastic deformation of the shift shaft hole 2 when the bolt is tightened. The deformation is concentrated in the critical meshing area of ​​the shift shaft hole 2. The root circle usually refers to the circle formed by the lowest points of all the tooth roots on the gear, and the root circle diameter refers to the diameter of the circle where the gear tooth roots are located, which will not be elaborated here. The root circle diameter is the core mating dimension between the internal spline tooth 4 and the shift shaft. The opening depth is designed in this proportion so that the elastic deformation mainly acts on the root and surrounding area of ​​the internal spline 4. This ensures that the internal spline 4 can contract evenly and fit tightly against the shift shaft when locked, avoiding insufficient deformation range and residual local meshing clearance due to insufficient depth; it also avoids structural failure caused by excessive deformation. If the depth is too deep (ratio greater than 1:3), the deformation will affect the non-meshing area of ​​the shift shaft hole 2, causing the shift shaft hole 2 to become out of round, damaging the meshing accuracy of the internal spline 4, and even causing the shift shaft to jam; if the inner side The depth h of the opening 5 does not exceed 1 / 3 of the root circle diameter, meaning that sufficient shaft hole wall thickness is still retained at the bottom of the opening. This material provides stable support for the internal spline 4, especially when transmitting large torques, preventing the internal spline 4 from breaking due to insufficient root support. At the same time, a depth of not less than 1 / 4 ensures that the opening will not become a stress concentration point due to being too shallow. An opening that is too shallow will cause deformation forces to concentrate at the edge of the opening, which is prone to edge cracks after long-term use. A depth range of 1:3 to 1:4 can disperse stress and prolong the life of the structure. Structural lifespan; Since the internal spline tooth 4 can extend to the edge of the inner opening 5, the ratio of the opening depth to the root circle diameter needs to match the length of the internal spline tooth 4. If the depth is too shallow, the root of the internal spline tooth 4 at the edge of the opening will be too short, making it easy to bend and deform during meshing; if the depth is too deep, the internal spline tooth 4 will extend to the bottom of the opening, resulting in a weak connection between the root and the bottom of the opening. A ratio of 1:3 to 1:4 can make the embedding depth of the internal spline tooth 4 at the edge of the opening match the root circle diameter, ensuring the structural integrity of the tooth. This will not be elaborated further here.

[0032] In this embodiment, the ratio between the width l of the inner opening 5 and the root circle diameter d of the shift shaft hole 2 is 1:4-1:5. When the shift gear seat 1 is bolted to the outer opening 3, the inner opening 5 needs to provide elastic deformation space simultaneously so that the shift shaft hole 2 can smoothly contract and hold the shift shaft. This ratio range ensures that the shift shaft hole 2 can generate sufficient radial contraction when locked, that is, the meshing clearance between the internal spline tooth 4 and the shift shaft is effectively eliminated, avoiding insufficient deformation and insufficient locking force due to an excessively narrow opening (ratio less than 1:5), thereby preventing loosening and slippage during shifting. At the same time, it avoids excessive structural weakness due to an excessively wide opening (ratio greater than 1:4). If the opening is too wide, the rigidity of the shift shaft hole 2 will decrease significantly. The method of stably bearing the torsional force of the shift shaft can lead to problems such as misalignment of the internal spline teeth 4. The diameter of the root circle is a key dimension of the internal spline teeth 4 structure, which is directly related to the fitting accuracy of the shift shaft. The opening width is designed according to the aforementioned ratio, which allows the elastic deformation to be mainly concentrated in the non-load-bearing area of ​​the internal spline teeth 4, that is, the shaft hole wall near the tooth root. This avoids the deformation range being too large and affecting the meshing accuracy of the internal spline teeth 4. The ratio of 1:4 to 1:5 limits the opening width to not excessively occupy the circumferential space of the shift shaft hole 2, so that most of the circumferential area of ​​the shift shaft hole 2 maintains the integrity of the structure. This intact area can provide solid support for the internal spline teeth 4, ensuring that the tooth root of the internal spline teeth 4 is not prone to breakage due to structural weakness when transmitting shift torque. This will not be elaborated further here.

[0033] In this embodiment, the two side walls of the outer opening 3 are provided with through bolt holes 6. In use, the shift shaft is installed by bolts passing through the bolt holes 6. The bolt holes 6 are as close as possible to the shift shaft hole 2 to minimize the ineffective deformation of the opening and ensure the stirrup force.

[0034] The motorcycle of this embodiment includes the aforementioned anti-loosening shift gear seat for the shift shaft. The internal spline 4 of the shift shaft hole 2 of the shift gear seat 1 extends to the transition between the outer opening 3 and the shift shaft hole 2, increasing the opening range of the internal spline 4. At the same time, the internal spline 4 is opened at the location where the fastening force is concentrated, improving the distribution of the fastening force on the concentrated side of the shift gear seat 1. This ensures sufficient clamping force while redistributing the torque transmitted from the shift shaft to the shift shaft hole 2, avoiding impact wear caused by rotational clearance, reducing slippage of the shift shaft relative to the shift gear seat 1 due to wear, and also solving the problem of axial loosening of the shift shaft due to wear during operation after the shift gear seat 1 is assembled with the shift shaft of the motorcycle, thus extending the service life of the shift gear seat 1.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A lock-up shift dog for a shift shaft, characterized by: The shift gear seat has a shift shaft hole with an outer opening. The shift shaft hole has internal splines for engaging with the shift shaft of a motorcycle. The internal splines include an upper internal spline and a lower internal spline. The upper internal spline extends to the transition between the shift shaft hole and the upper sidewall of the outer opening, or / and the lower internal spline extends to the transition between the shift shaft hole and the lower sidewall of the outer opening.

2. A lock-up shift dog for a shift shaft according to claim 1, characterized in that: An inner opening is provided on the other side of the shift gear seat, which is radially opposite to the outer opening in the shift shaft hole.

3. A lock-up shift dog for a shift shaft according to claim 2, characterized in that: The opening range of the upper internal spline extends to the transition between the shift shaft hole and the upper sidewall of the inner opening.

4. The lock-up shift dog for a shift shaft as set forth in claim 2, characterized by: The opening range of the lower internal spline extends to the transition between the shift shaft hole and the lower sidewall of the inner opening.

5. The lock-up shift dog for a shift shaft as set forth in claim 2, characterized by: The inner opening is either a rectangular opening or an arc-shaped opening.

6. A lock-up shift dog for a shift shaft according to claim 5, characterized in that: The inner opening and the outer opening are directly opposite each other in the radial direction of the shift shaft hole.

7. A lock-up shift dog for a shift shaft according to claim 6, characterized in that: The ratio between the depth h of the inner opening and the root circle diameter d of the shift shaft hole is 1:3-1:

4.

8. The anti-loosening shift gear seat for a shift shaft according to claim 6, characterized in that: The ratio between the width l of the inner opening and the root circle diameter d of the shift shaft hole is 1:4-1:

5.

9. The anti-loosening shift gear seat for a shift shaft according to claim 1, characterized in that: The outer opening has through bolt holes on both sides, and the bolt holes are located as close as possible to the shift shaft hole.

10. A motorcycle, characterized in that: Including the anti-loosening shift gear seat for shift shaft as described in any one of claims 1-9.

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