CN218400877U

CN218400877U - Motorcycle gearshift

Info

Publication number: CN218400877U
Application number: CN202222527290.8U
Authority: CN
Inventors: 曾右华; 王卫东; 崔兴健; 邓国久
Original assignee: Chongqing Haosen Motorcycle Co ltd
Current assignee: Chongqing Haosen Motorcycle Co ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2023-01-31
Anticipated expiration: 2032-09-23

Abstract

The utility model discloses a motorcycle gear shift mechanism, which comprises a main shaft, an auxiliary shaft, a reverse gear idler wheel and a speed change drum, wherein a forward gear driving tooth and a reverse gear driving tooth are sleeved on the main shaft in an empty way, and a forward gear driven tooth and a reverse gear driven tooth are fixedly sleeved on the auxiliary shaft; the main shaft is also sleeved with a gear shifting tooth, the gear shifting tooth is connected with the main shaft key and can be connected with the forward gear driving tooth or the reverse gear driving tooth after sliding along the axial direction of the main shaft under the stirring of a shifting fork so as to drive the forward gear driving tooth or the reverse gear driving tooth to rotate; the shifting drum is positioned on one side of the main shaft, a shifting fork guide groove is formed in the outer circle of the shifting drum, one end of the shifting fork is arranged in the shifting fork guide groove, and the other end of the shifting fork is connected with the gear shifting teeth; the reverse gear protection device is arranged on the forward gear driving tooth, the tail end of the reverse gear protection device extends towards the direction of the speed change drum, the reverse gear protection device is in press fit with the forward gear driving tooth, and when the forward gear driving tooth rotates, the tail end of the reverse gear protection device can be pressed on the speed change drum, so that the speed change drum is locked at the current position.

Description

Motorcycle gearshift

Technical Field

The utility model relates to a motorcycle engine variable speed field, concretely relates to motorcycle gearshift.

Background

The conventional motorcycle gear shifting mechanism mainly comprises a main shaft and an auxiliary shaft, wherein a forward gear driving tooth and a reverse gear driving tooth are sleeved on the main shaft, and a forward gear driven tooth and a reverse gear driven tooth which are meshed with the forward gear driving tooth are sleeved on the auxiliary shaft. For example, chinese patent publication No. 1483926 discloses a built-in self-locking reverse gear device for a motorcycle, which comprises a main shaft, an auxiliary shaft, a shift drum, a shift fork, a meshing sleeve, a reverse drive wheel, a reverse driven wheel, and a reverse idle wheel, and further comprises an elastic member, a limit pawl, a positioning member, and a limit device, wherein the elastic member and the limit pawl are sleeved on the auxiliary shaft and are pressed against the end face of a shaft shoulder or a gear by an axial positioning member, and the outer circle of the shift drum is provided with the reverse limit device. When the motorcycle moves forwards, the operating vehicle treads a gear shifting pedal forwards, the gear shifting lever enables the gear shifting drum to rotate, the gear shifting drum rotates to be converted into axial sliding of the meshing sleeve under the action of the shifting fork, at the moment, the meshing sleeve slides to a flower groove of the forward driving wheel, the forward gear is meshed (at the moment, the reverse driving wheel can only idle at the main shaft and cannot transmit power), the auxiliary shaft rotates forwards, and the motorcycle moves forwards. Due to the elastic force of the elastic component, when the auxiliary shaft rotates, a friction torque is applied to the limiting pawl, the limiting pawl rotates along with the auxiliary shaft, after the auxiliary shaft rotates for a certain angle, the limiting pawl touches the outer circle of the speed changing drum, due to the blocking of the speed changing drum, the limiting pawl does not rotate along with the auxiliary shaft, and due to the fact that the driving torque is larger than the friction torque, sliding is generated between the auxiliary shaft and the limiting pawl, the friction torque exists continuously, the limiting pawl is pressed against the outer circle surface of the speed changing drum, at the moment, if misoperation is carried out, when the speed changing drum rotates towards the reverse gear direction, the speed changing drum slides relative to the limiting pawl, due to the fact that the reverse gear limiting device is arranged on the outer circle of the speed changing drum, when the speed changing drum rotates to the neutral gear position, the limiting device can prevent the speed changing drum from rotating continuously. Therefore, the safety of the forward running of the motorcycle is guaranteed.

Above-mentioned structure is though can effectively ensure when advancing, and spacing pawl is by pressing on the outer disc of variable speed drum for the variable speed drum can't rotate, can prevent to make the rotatory back of variable speed drum because of the maloperation under the fender that advances, and the collision after the drive tooth that reverses gear and the driven tooth meshing of reversing gear damages the gear. However, the limit locking mechanism is assembled on the auxiliary shaft, the speed changing drum can only realize the pressing of the reverse gear limit device on the speed changing drum when the auxiliary shaft rotates clockwise, and in the application, the speed changing drum rotates anticlockwise when the auxiliary shaft rotates clockwise. If need the variable speed drum anticlockwise rotation, need operating personnel to trample forward and just can realize, and this kind of operation is not conform to consumer's use habit for the personnel of riding when riding, the maloperation appears very easily, influences the impression of riding and damages the gear.

Disclosure of Invention

Not enough to the above that prior art exists, the utility model aims to provide a reverse gear protection device who uses habit to suit with the personnel of riding, step on the variable speed pedal before when moving ahead promptly, step on the variable speed pedal after when reversing gear, realize the protection of reversing gear to adapt to the personnel of riding's use habit.

In order to solve the technical problem, the utility model discloses a following technical scheme:

a motorcycle gear shift mechanism comprises a main shaft, an auxiliary shaft and a gear shift drum, wherein a forward gear driving tooth and a reverse gear driving tooth are sleeved on the main shaft in a hollow manner, a forward gear driven tooth and a reverse gear driven tooth are fixedly sleeved on the auxiliary shaft in a fixed manner, and the forward gear driving tooth is meshed with the forward gear driven tooth; a reverse gear idle wheel is arranged between the reverse gear driving tooth and the reverse gear driven tooth, and the reverse gear idle wheel is meshed with the reverse gear driving tooth and the reverse gear driven tooth; the gear shifting mechanism is characterized in that a gear shifting tooth is further sleeved on the main shaft, is positioned between the forward gear driving tooth and the reverse gear driving tooth, is in key connection with the main shaft, can slide along the axial direction of the main shaft under the stirring of a shifting fork, and is connected with the forward gear driving tooth or the reverse gear driving tooth to drive the forward gear driving tooth or the reverse gear driving tooth to rotate; the speed change drum is positioned on one side of the main shaft, a shifting fork guide groove is formed in the excircle of the speed change drum, one end of the shifting fork is arranged in the shifting fork guide groove, and the other end of the shifting fork is connected with the gear shifting teeth; the reverse gear protection device is arranged on the forward gear driving tooth, the tail end of the reverse gear protection device extends towards the direction of the speed change drum, the reverse gear protection device is in press fit with the forward gear driving tooth, when the forward gear driving tooth rotates, the tail end of the reverse gear protection device can be pressed on the speed change drum, the speed change drum is locked at the current position, the speed change drum is prevented from rotating, meanwhile, after the forward gear driving tooth stops rotating, the reverse gear protection device lightly leans on the speed change drum, and the speed change drum is unlocked.

Furthermore, the shifting fork guide groove is composed of an upper arc-shaped groove, a hollow retaining transverse groove and a lower arc-shaped groove which are communicated with each other, the hollow retaining transverse groove is positioned between the upper arc-shaped groove and the lower arc-shaped groove, the vertical height from the tail end of the upper arc-shaped groove to the tail end of the lower arc-shaped groove corresponds to the sliding distance of the gear shifting teeth, the upper arc-shaped groove corresponds to the lower end of the forward gear driving teeth, and the lower arc-shaped groove corresponds to the reverse gear driving teeth.

Further, the gear shift drum is shifted in a reciprocating rotation mode, namely a forward gear, a neutral gear and a reverse gear, or the reverse gear, the neutral gear and the forward gear; when the speed changing drum rotates anticlockwise, the shifting fork slides from bottom to top to drive the gear shifting teeth to enter a forward gear from a neutral gear or enter the neutral gear from a reverse gear; when the variable speed drum rotates clockwise, the shifting fork slides from top to bottom to drive the gear shifting teeth to enter a neutral gear from a forward gear or enter a reverse gear from the neutral gear.

Furthermore, the reverse gear protection device is plate-shaped and is sleeved on the forward gear driving tooth, the two ends of the reverse gear protection device and the forward gear protection tooth are respectively provided with a wave-shaped gasket and a retainer ring, the reverse gear protection device is positioned between the retainer ring and the wave-shaped gasket, and the retainer ring tightly presses the reverse gear protection device and the wave-shaped gasket on the end face of the forward gear driving tooth; a limiting groove corresponding to the tail end of the reverse gear protection device is arranged on the excircle of the speed changing drum, and an insertion opening of the limiting groove is formed in one side, close to the reverse gear protection device.

Furthermore, an annular clamping groove is formed in one end, far away from the gear shifting tooth, of the forward gear driving tooth, the reverse gear protection device is composed of an installation portion and an insertion portion, the middle portion of the installation portion is provided with an installation hole, the insertion portion extends to one side of the installation portion, and the installation hole of the installation portion is matched with the annular clamping groove.

Furthermore, the tail end of the insertion part is bent towards the direction of the limiting groove and corresponds to the opening side of the limiting groove, and the tail end of the insertion part is arc-shaped.

Furthermore, the depth of the limiting groove body is gradually increased from the insertion hole to the other end, and the deeper side of the limiting groove body is arc-shaped.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the reverse gear protection device is arranged on a forward gear of the main shaft, so that the variable speed pedal is treaded backwards when the main shaft moves forwards, the reverse gear protection is realized through the rotation of the forward gear when the main shaft moves forwards, and the reverse gear protection device is more in line with ergonomics.

2. The operation habit of the riding personnel can be better met.

3. And the gear is more effectively prevented from being damaged by misoperation.

Drawings

FIG. 1 is a schematic view of a shifting mechanism of a motorcycle in a neutral state in an embodiment;

FIG. 2 is a schematic view of the drum in the embodiment shown deployed;

FIG. 3 is a schematic view showing a mounting structure of a shift drum in the embodiment;

FIG. 4 is a schematic view of the mounting structure of the shift pedal and shift drum assembly in the embodiment.

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the attached drawings in the embodiments of the present invention will be combined below to clearly and completely describe the technical solution in the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance. Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined. In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood as a specific case by those skilled in the art.

As shown in fig. 1 to fig. 3, the motorcycle gear shift mechanism provided in this embodiment includes a main shaft 1, an auxiliary shaft 8 and a shift drum 11, a forward gear driving tooth 5 and a reverse gear driving tooth 7 are sleeved on the main shaft 1 in a hollow manner, a forward gear driven tooth 9 and a reverse gear driven tooth 10 are fixedly sleeved on the auxiliary shaft 8, the forward gear driving tooth 5 is engaged with the forward gear driven tooth 9, a reverse gear idle wheel 18 is disposed between the reverse gear driving tooth 7 and the reverse gear driven tooth 10, and the reverse gear idle wheel 18 is engaged with the reverse gear driven tooth 10 after being engaged with the reverse gear driving tooth 7; the main shaft 1 is also sleeved with a gear shifting tooth 6, the gear shifting tooth 6 is positioned between the forward gear driving tooth 5 and the reverse gear driving tooth 7, is connected with the main shaft 1 in a key manner, can slide along the axial direction of the main shaft 1 under the stirring of a shifting fork 16, and is connected with the forward gear driving tooth 5 or the reverse gear driving tooth 7 to drive the forward gear driving tooth 5 or the reverse gear driving tooth 7 to rotate; the gear shifting drum 11 is positioned on one side of the main shaft 1, a shifting fork 16 guide groove 13 is formed in the outer circle of the gear shifting drum 11, one end of the shifting fork 16 is arranged in the shifting fork 16 guide groove 13, and the other end of the shifting fork 16 is connected with gear shifting teeth; the gear shift drum 11 is shifted in a reciprocating rotation mode, namely, a forward gear, a neutral gear and a reverse gear, or the reverse gear, the neutral gear and the forward gear; when the speed changing drum 11 rotates anticlockwise, the shifting fork 16 slides from bottom to top to drive the gear shifting teeth to enter a forward gear from a neutral gear or enter the neutral gear from a reverse gear; when the variable speed drum 11 rotates clockwise, the shifting fork 16 slides from top to bottom to drive the gear shifting teeth 6 to enter a neutral gear from a forward gear or enter a reverse gear from the neutral gear. The reverse gear protection device 3 is arranged on the forward gear driving tooth 5, the tail end of the reverse gear protection device extends towards the direction of the speed changing drum 11, the reverse gear protection device 3 is in press fit with the forward gear driving tooth 5, when the forward gear driving tooth 5 rotates, the tail end of the reverse gear protection device can lean against the speed changing drum 11 to lock the speed changing drum 11 at the current position, the speed changing drum 11 is prevented from rotating, and meanwhile, after the forward gear driving tooth 5 stops rotating, the reverse gear protection device 3 lightly leans against the speed changing drum 11, and the speed changing drum 11 is unlocked.

Specifically, the reverse gear protection device 3 in this embodiment is plate-shaped, and is sleeved on the forward gear driving tooth 5, the two ends of the reverse gear protection device 3 and the forward gear protection tooth are respectively provided with the wave washer 4 and the retainer ring 2, the reverse gear protection device 3 is located between the retainer ring 2 and the wave washer 4, and the retainer ring 2 tightly presses the reverse gear protection device 3 and the wave washer 4 on the end surface of the forward gear driving tooth 5 (this arrangement can ensure that when the forward gear driving tooth 5 rotates, friction torque is transmitted to the reverse gear protection device 3 through the wave washer 4, so that the reverse gear protection device 3 is pressed against the shift drum 11 to press the shift drum 11 to prevent the shift drum 11 from rotating, and at the same time, when the forward gear driving tooth 5 does not rotate, the reverse gear protection device 3 is only adhered to the shift drum 11, no external force is applied, and the shift drum 11 is ensured to be driven by external force to rotate); a limiting groove 12 corresponding to the tail end of the reverse gear protection device 3 is arranged on the excircle of the speed changing drum 11, and an insertion opening of the limiting groove 12 is arranged close to one side of the reverse gear protection device 3. The limiting groove 12 arranged on the shift drum 11 can facilitate the insertion of the tail end of the reverse gear protection device 3, so that the tail end of the reverse gear protection device is not tangent to the reverse gear protection device 3, the applied downward pressure is larger, and the tail end of the reverse gear protection device 3 is effectively ensured to have larger friction force after being inserted into the limiting groove 12.

In operation, when a rider steps on the shift pedal 15 when the rider moves forward, the shift lever assembly 14 connected with the shift pedal is driven to move, so that the shift drum 11 is driven to rotate anticlockwise, and after the shift drum 11 rotates anticlockwise, the shift fork 16 is driven to move upwards to be connected with the forward gear driving tooth 5. Therefore, under the driving of the main shaft 1, the forward gear driving tooth 5 and the gear shifting tooth rotate together to drive the forward gear driven tooth 9 to rotate anticlockwise (at the moment, the reverse gear driving wheel can only idle on the main shaft 1 and can not transmit power), the auxiliary shaft 8 rotates clockwise, and the motorcycle runs forwards. In the forward process, the tail end of the reverse gear protection device 3 on the forward gear driving tooth 5 is in contact with the outer circular surface of the speed changing drum 11 and is far away from the limiting groove 12, and meanwhile, when the forward gear driving tooth 5 rotates, due to the action of the wave washer 4, when the main shaft 1 rotates, a friction torque is applied to the reverse gear protection device 3, so that the reverse gear protection device 3 is pressed against the outer circular surface of the speed changing drum 11 under the action of the friction force. At this time, if the shift lever is operated by mistake and the shift drum 11 is driven to rotate clockwise, the shift drum 11 cannot rotate clockwise because the reverse gear protection device 3 is pressed against the outer circumferential surface and the tail end of the reverse gear protection device abuts against the limiting groove 12. Therefore, the safety of the forward running of the motorcycle is guaranteed.

When the motorcycle stops, the forward driving gear 5 stops rotating, and at this time, the reverse gear protection device 3 no longer has friction force and cannot be pressed on the speed change drum 11, so that the speed change drum 11 can rotate. At this time, if the motorcycle needs to retreat, the rider can normally engage the shift position.

In addition, when the motorcycle is in neutral (as shown in fig. 1), and the driver slides forward to drive the motorcycle to move forward, the auxiliary shaft 8 rotates, so as to drive the forward gear driven teeth 9 to rotate, and further drive the forward gear driving teeth 5 engaged with the forward gear driven teeth 9 to rotate. When the forward gear driving tooth 5 rotates, a torque force is applied to the reverse gear protection device 3, so that the reverse gear protection device 3 can be pressed on the speed change drum 11 to prevent the speed change drum 11 from rotating, the reverse gear is prevented from being operated by mistake in the sliding process, and the situation that the gear is damaged by collision can be avoided.

As shown in fig. 2, the shift fork guide groove 13 in this embodiment is composed of an upper arc-shaped groove 131, a hollow transverse groove 132 and a lower arc-shaped groove 133 which are communicated with each other, the hollow transverse groove 132 is located between the upper arc-shaped groove 131 and the lower arc-shaped groove 133, the vertical height from the end of the upper arc-shaped groove 131 to the end of the lower arc-shaped groove 133 corresponds to the sliding distance of the shift tooth 6, the upper arc-shaped groove 131 corresponds to the lower end of the forward drive tooth 5, and the lower arc-shaped groove 133 corresponds to the reverse drive tooth 7. This setting can effectively guarantee variable speed drum anticlockwise rotation, and the shift fork is stirred to the last arc wall direction, and clockwise rotation, shift fork slip to the lower arc wall.

As shown in fig. 3 and 4, in the present embodiment, the rotation direction of the shift lever assembly 14 for shifting the shift drum 11 to rotate can be changed by stepping on the shift pedal in different directions, so as to realize that the shift pedal is stepped on forward to enter the forward gear; the speed change pedal is pedaled backwards to enter a reverse gear. Specifically, when the operator steps forward on the front pedal of the shift pedal, the shift lever assembly 14 connected to the shift pedal is rotated, thereby rotating the shift drum 11 counterclockwise. When the operator steps on the rear pedal of the shift pedal, the shift lever assembly 14 connected to the shift pedal is rotated in the reverse direction, and the shift drum 11 is rotated clockwise. The shifting fork 16 guide groove 13 is composed of an upper arc-shaped groove, a hollow gear transverse groove and a lower arc-shaped groove which are communicated with each other, the hollow gear transverse groove is positioned between the upper arc-shaped groove and the lower arc-shaped groove, the vertical height from the tail end of the upper arc-shaped groove to the tail end of the lower arc-shaped groove corresponds to the sliding distance of the gear shifting teeth, the upper arc-shaped groove corresponds to the lower end of the forward gear driving tooth 5, and the lower arc-shaped groove corresponds to the reverse gear driving tooth 7.

In order to install the reverse gear protection device 3, an annular clamping groove is formed in one end, far away from the shifting tooth, of the forward gear driving tooth 5, the reverse gear protection device 3 is composed of an installation portion and an insertion portion, the middle portion of the installation portion is provided with an installation hole, the insertion portion extends to one side of the installation portion, and the installation hole of the installation portion is matched with the annular clamping groove. In order to increase the compressive strength of the tail end of the reverse gear protection device 3, the tail end of the insertion part is bent towards the direction of the limiting groove 12 and corresponds to the opening side of the limiting groove 12. Meanwhile, in order to ensure that the reverse gear protection device 3 can be well matched with the limiting groove 12 and is convenient to withdraw from the limiting groove 12 when not pressed, the tail end of the insertion part is arc-shaped. The depth of the groove body of the limiting groove 12 is gradually increased from the insertion opening to the other end, and the deeper side is arc-shaped.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that those modifications or equivalent substitutions to the technical solutions of the present invention should be included in the scope of the claims of the present invention without departing from the spirit and scope of the technical solutions.

Claims

1. A motorcycle gear shift mechanism comprises a main shaft, an auxiliary shaft and a gear shift drum, wherein a forward gear driving tooth and a reverse gear driving tooth are sleeved on the main shaft in a hollow manner, a forward gear driven tooth and a reverse gear driven tooth are fixedly sleeved on the auxiliary shaft in a fixed manner, and the forward gear driving tooth is meshed with the forward gear driven tooth; a reverse gear idler wheel is also arranged between the reverse gear driving tooth and the reverse gear driven tooth, and the reverse gear idler wheel is meshed with the reverse gear driving tooth and the reverse gear driven tooth; the gear shifting mechanism is characterized in that a gear shifting tooth is further sleeved on the main shaft, is positioned between the forward gear driving tooth and the reverse gear driving tooth, is in key connection with the main shaft, can slide along the axial direction of the main shaft under the stirring of a shifting fork, and is connected with the forward gear driving tooth or the reverse gear driving tooth to drive the forward gear driving tooth or the reverse gear driving tooth to rotate; the shifting drum is positioned on one side of the main shaft, a shifting fork guide groove is formed in the outer circle of the shifting drum, one end of the shifting fork is arranged in the shifting fork guide groove, and the other end of the shifting fork is connected with the gear shifting teeth; the reverse gear protection device is arranged on the forward gear driving tooth, the tail end of the reverse gear protection device extends towards the direction of the speed change drum, the reverse gear protection device is in press fit with the forward gear driving tooth, when the forward gear driving tooth rotates, the tail end of the reverse gear protection device can be pressed on the speed change drum, the speed change drum is locked at the current position, the speed change drum is prevented from rotating, meanwhile, after the forward gear driving tooth stops rotating, the reverse gear protection device lightly leans on the speed change drum, and the speed change drum is unlocked.

2. The motorcycle shift mechanism according to claim 1, wherein the shift fork guide groove is composed of an upper arc-shaped groove, a hollow shift transverse groove and a lower arc-shaped groove which are communicated with each other, the hollow shift transverse groove is located between the upper arc-shaped groove and the lower arc-shaped groove, a vertical height from a terminal of the upper arc-shaped groove to a terminal of the lower arc-shaped groove corresponds to a sliding distance of the shift tooth, the upper arc-shaped groove corresponds to a lower end of the forward shift driving tooth, and the lower arc-shaped groove corresponds to the reverse shift driving tooth.

3. A motorcycle gear change mechanism according to claim 2, wherein the shift drum is shifted in a reciprocating rotational manner, i.e. forward, neutral, reverse, or reverse, neutral, forward; when the speed changing drum rotates anticlockwise, the shifting fork slides from bottom to top to drive the gear shifting teeth to enter a forward gear from a neutral gear or enter the neutral gear from a reverse gear; when the variable speed drum rotates clockwise, the shifting fork slides from top to bottom to drive the gear shifting teeth to enter a neutral gear from a forward gear or enter a reverse gear from the neutral gear.

4. A motorcycle gear shift mechanism according to claim 1, 2 or 3, wherein the reverse gear guard is plate-shaped and fitted over the forward gear driving tooth, and a wave washer and a retainer ring are provided at both ends of the reverse gear guard and the forward gear guard tooth, respectively, the reverse gear guard being located between the retainer ring and the wave washer, the retainer ring pressing the reverse gear guard and the wave washer against the end face of the forward gear driving tooth; the outer circle of the speed changing drum is provided with a limiting groove corresponding to the tail end of the reverse gear protection device, and an insertion hole of the limiting groove is formed in one side, close to the reverse gear protection device.

5. A motorcycle gear shift mechanism according to claim 4, wherein an annular notch is provided at an end of the forward drive tooth remote from the shift tooth, and the reverse guard is composed of a mounting portion having a fitting hole at a middle portion thereof and an insertion portion extending on a side of the mounting portion, the fitting hole of the mounting portion being fitted with the annular notch.

6. A motorcycle gear shift mechanism according to claim 5, wherein the end of the insertion part is bent toward the direction of the limit groove, and laterally corresponds to the opening of the limit groove, and the end of the insertion part is arc-shaped.

7. A motorcycle gear shift mechanism according to claim 5 or 6, wherein the depth of the stopper groove body becomes gradually larger from the insertion opening to the other end, and the deeper side is arc-shaped.