Gear shifting structure of motorcycle engine

Abstract

The utility model belongs to the technical field of motorcycle engines, and relates to a gear shifting structure of a motorcycle engine, which comprises a gearbox body, a driving shaft in transmission connection with a crankshaft and an output shaft in transmission connection with a load are arranged in the gearbox body, and the driving shaft is in transmission connection with the output shaft through a gear shifting mechanism. The gear shifting mechanism comprises a gear set and a shifting fork changing the connecting state of the gear set, a stepping motor is arranged on the outer side of the gearbox body, a crank is arranged on a motor shaft of the stepping motor in a sleeved mode, the crank is hinged to one end of a connecting rod, the other end of the connecting rod is hinged to the shifting fork, and the shifting fork is arranged on a guide rod in a sliding mode. The guide rod is parallel to the driving shaft and the output shaft, and the stepping motor drives the shifting fork to slide in the axial direction of the guide rod so as to complete the gear shifting action. According to the gear shifting structure of the motorcycle engine, automatic gear shifting of a motorcycle can be achieved.

Description

Technical Field

[0001] This utility model belongs to the technical field of motorcycle engines and relates to a shifting structure for a motorcycle engine. Background Technology

[0002] Existing motorcycles generally use a mechanical shifting mechanism, which requires foot pedal to shift gears. This mechanical structure is relatively complex and has a high production cost. Each shift requires foot pedaling, and since everyone's force is different, the shifting experience varies from person to person. Some people find the shifting inflexible, while others find it too fast.

[0003] Chinese utility model CN201884614U (publication date: 2011.06.29) discloses an electric motorcycle transmission, including a transmission housing, a transmission mechanism, and a shifting mechanism. The transmission mechanism and the shifting mechanism are installed in the transmission housing and are located at the lower and upper parts of the transmission housing, respectively. The electric motor in the transmission mechanism is installed on the right side of the transmission housing, and the housing of the electric motor is integral with the transmission housing.

[0004] The aforementioned transmission uses a stepper motor for gear shifting. Its specific structure includes a stepper motor and a small gear at the output end of the stepper motor, a gear shift drum and a large gear at the end of the gear shift drum, and a first shift fork and a second shift fork mounted on the gear shift drum. The small gear and the large gear mesh. The outer end of the first shift fork extends into the circumferential groove of the second driven gear, and the outer end of the second shift fork extends into the circumferential groove of the third driven gear. In actual production, gear shift drums and other mechanisms utilize cam profiles to achieve gear shifting. To achieve precise gear shifting, the gear shift drum requires high machining accuracy, thus increasing machining difficulty and costs. Utility Model Content

[0005] This utility model addresses the shortcomings of existing technologies by providing a shifting structure for a motorcycle engine, which enables automatic shifting of the motorcycle. It has the advantages of simple structure, convenient operation, flexible and precise shifting, low processing precision requirements, and low cost.

[0006] To solve the above-mentioned technical problems, the objective of this utility model is achieved through the following technical solution:

[0007] A shifting structure for a motorcycle engine includes a gearbox housing. The gearbox housing houses a drive shaft connected to a crankshaft and an output shaft connected to a load. The drive shaft and output shaft are connected via a shifting mechanism. The shifting mechanism includes a gear set and a shift fork that changes the connection state of the gear set. A stepper motor is mounted on the outside of the gearbox housing. A crank is mounted on the motor shaft of the stepper motor. One end of the crank is hinged to a connecting rod, and the other end of the connecting rod is hinged to the shift fork. The shift fork is slidably mounted on a guide rod, which is parallel to the drive shaft and the output shaft. The stepper motor drives the shift fork to slide axially along the guide rod to complete the shifting action.

[0008] In the aforementioned shifting structure of a motorcycle engine, the crankshaft is connected to the drive shaft via a CVT system.

[0009] In the aforementioned shifting structure of a motorcycle engine, the shift fork is connected in the central groove of the engagement sleeve, the engagement sleeve is slidably mounted on the intermediate shaft, and a first gear and a second gear are mounted on the intermediate shaft on both sides of the engagement sleeve. The engagement sleeve is driven by the shift fork and can selectively connect and transmit power with the first gear and the second gear.

[0010] In the aforementioned shifting structure of a motorcycle engine, the inner ring of the engagement sleeve is connected to the intermediate shaft via a spline drive, and the engagement sleeve is connected to the first gear and the second gear via a matching protrusion and groove structure. The first gear and the second gear are rotatably connected to the intermediate shaft. In this utility model, the engagement structure of the engagement sleeve and the first gear and the second gear is the same as in the prior art.

[0011] In the aforementioned shifting structure of a motorcycle engine, a drive gear is provided on the drive shaft, and the drive gear meshes with a first gear on the intermediate shaft and a third gear on the transition shaft. An intermediate gear is provided on the intermediate shaft, and the intermediate gear meshes with a fourth gear mounted on the output shaft. A transition gear is provided on the transition shaft, and the transition gear meshes with a second gear on the intermediate shaft.

[0012] In the aforementioned shifting structure of a motorcycle engine, preferably, the drive teeth, intermediate teeth, and transition teeth all adopt a helical tooth structure, and the first gear, second gear, third gear, and fourth gear adopt a helical tooth structure adapted to it.

[0013] In the aforementioned shifting structure of a motorcycle engine, the drive shaft, intermediate shaft, transition shaft, output shaft, and guide rod are arranged in parallel. The two ends of the drive shaft, intermediate shaft, transition shaft, and output shaft are rotatably connected to the gearbox body and supported by bearings, while the two ends of the guide rod are fixedly connected to the gearbox body.

[0014] In the aforementioned shifting structure of a motorcycle engine, the gearbox body is provided with a motor mounting slot, and the gearbox body corresponding to the motor mounting slot is provided with a motor mounting surface and a motor bearing seat. The motor bearing seat is provided with a motor bearing that supports the motor shaft. The front end face of the stepper motor is in contact with the motor mounting surface, the motor shaft passes through the motor bearing and through the gearbox body, and the rear end of the stepper motor is fixedly connected to the gearbox body through the motor mounting seat.

[0015] Compared with the prior art, this utility model has the following advantages:

[0016] This invention provides a gear shifting structure for a motorcycle engine. By driving a shift fork to slide via a stepper motor and linkage mechanism, automatic gear shifting is achieved. This invention also avoids the use of a gear drum and other parts with complex cam profiles, thus reducing manufacturing difficulty and costs. Compared to traditional structures, this invention offers more precise gear shifting positions and faster, more accurate shifting times, and reduced manufacturing costs due to fewer components. It also simplifies maintenance and repair. Therefore, this invention has the advantages of simple structure, convenient operation, flexible and precise gear shifting, low machining precision requirements, and low cost. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present invention;

[0018] Figure 2 This is an internal perspective view of the present invention;

[0019] Figure 3 This is a perspective view of the transmission structure of this utility model;

[0020] Figure 4 This is a perspective view of the stepper motor drive structure of this utility model;

[0021] Figure 5 This is a perspective view of the gearbox of this utility model;

[0022] Reference numerals: 1. Gearbox housing; 2. Drive shaft; 3. Output shaft; 4. Shift fork; 5. Stepper motor; 6. Crank; 7. Connecting rod; 8. Guide rod; 9. Engaging sleeve; 10. Intermediate shaft; 11. First gear; 12. Second gear; 13. Drive gear; 14. Transition shaft; 15. Third gear; 16. Intermediate gear; 17. Fourth gear; 18. Transition gear; 19. Motor mounting slot; 20. Motor mounting surface; 21. Motor bearing housing; 22. Motor mounting base. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-5 :

[0024] A shifting structure for a motorcycle engine includes a gearbox body 1. The gearbox body 1 houses a drive shaft 2, which is connected to a crankshaft, and an output shaft 3, which is connected to a load. The drive shaft 2 and the output shaft 3 are connected via a shifting mechanism. The shifting mechanism includes a gear set and a shift fork 4 that changes the connection state of the gear set. A stepper motor 5 is mounted on the outside of the gearbox body 1. A crank 6 is mounted on the motor shaft of the stepper motor 5. One end of the crank 6 is hinged to a connecting rod 7, and the other end of the connecting rod 7 is hinged to the shift fork 4. The shift fork 4 is slidably mounted on a guide rod 8. The guide rod 8 is parallel to the drive shaft 2 and the output shaft 3. The stepper motor 5 drives the shift fork 4 to slide axially along the guide rod 8 to complete the shifting action.

[0025] Comparison Appendix Figure 2 To be continued Figure 4 The shifting mechanism of this embodiment further includes: the shift fork 4 is connected in the central groove of the engagement sleeve 9, the engagement sleeve 9 is slidably disposed on the intermediate shaft 10, and the intermediate shaft 10 on both sides of the engagement sleeve 9 is fitted with a first gear 11 and a second gear 12, and the engagement sleeve 9 is driven by the shift fork 4 to selectively connect and transmit power with the first gear 11 and the second gear 12.

[0026] Furthermore, the inner ring of the engagement sleeve 9 is connected to the intermediate shaft 10 via a spline drive, and the engagement sleeve 9 is connected to the first gear 11 and the second gear 12 via a matching protrusion and groove structure. The first gear 11 and the second gear 12 are rotatably connected to the intermediate shaft 10. In this embodiment, the engagement structure of the engagement sleeve 9 and the first gear 11 and the second gear 12 is the same as in the prior art, and the method of connecting the engagement sleeve 9 to the first gear 11 and the second gear 12 by shifting the shift fork 4 is also the same as in the prior art.

[0027] Furthermore, the drive shaft 2 is provided with drive teeth 13, which mesh with the first gear 11 on the intermediate shaft 10 and the third gear 15 on the transition shaft 14. The intermediate shaft 10 is provided with intermediate teeth 16, which mesh with the fourth gear 17 mounted on the output shaft 3. The transition shaft 14 is provided with transition teeth 18, which mesh with the second gear 12 on the intermediate shaft 10.

[0028] The shifting method in this embodiment is:

[0029] When the stepper motor 5 is started, the motor axis of the stepper motor 5 rotates in a predetermined direction and at a predetermined angle. The crankshaft mounted on the motor shaft rotates accordingly. The crankshaft pulls the shift fork 4 along the axial direction defined by the guide rod 8 through the connecting rod 7, thereby driving the engagement sleeve 9 to slide along the axial direction of the intermediate shaft 10. When the engagement sleeve 9 slides to both ends, it connects with the first gear 11 or the second gear 12 respectively, and at the same time separates from the other gear.

[0030] When the meshing sleeve 9 is connected to the first gear 11, the crankshaft drives the drive shaft 2 to rotate through the transmission system, and the drive gear 13 rotates accordingly. The drive gear 13 drives the first gear 11 and the third gear 15 that mesh with it to rotate. The first gear 11 drives the intermediate shaft 10 to rotate through the meshing sleeve 9, and the intermediate gear 16 on the intermediate shaft 10 rotates accordingly. The intermediate gear 16 drives the fourth gear 17 that meshes with it to rotate, and the fourth gear 17 drives the output shaft 3 to rotate to output power. At the same time, the third gear 15 drives the transition shaft 14 to rotate, and the transition gear 18 on the transition shaft 14 rotates accordingly. The transition gear 18 drives the second gear 12 that meshes with it to rotate. The second gear 12 is not connected to the meshing sleeve 9 and is in an idle state.

[0031] When the meshing sleeve 9 is connected to the second gear 12, the crankshaft drives the drive shaft 2 to rotate through the transmission system, and the drive gear 13 rotates accordingly. The drive gear 13 drives the first gear 11 and the third gear 15 that mesh with it to rotate. The first gear 11 is not connected to the meshing sleeve 9 and is in an idle state. The third gear 15 drives the transition shaft 14 to rotate, and the transition gear 18 on the transition shaft 14 rotates accordingly. The transition gear 18 drives the second gear 12 that meshes with it to rotate. The second gear 12 drives the intermediate shaft 10 to rotate through the meshing sleeve 9, and the intermediate gear 16 on the intermediate shaft 10 rotates accordingly. The intermediate gear 16 drives the fourth gear 17 that meshes with it to rotate. The fourth gear 17 drives the output shaft 3 to rotate to output power.

[0032] This embodiment can be applied to existing CVT continuously variable transmission motorcycles. Specifically, the crankshaft is connected to the drive shaft 2 via a CVT system.

[0033] To make the transmission smoother and more reliable, preferably, the drive tooth 13, intermediate tooth 16 and transition tooth 18 all adopt helical tooth structure, and the first gear 11, second gear 12, third gear 15 and fourth gear 17 adopt helical tooth structure adapted to it.

[0034] Preferably, the drive shaft 2, intermediate shaft 10, transition shaft 14, output shaft 3 and guide rod 8 are arranged in parallel. The two ends of the drive shaft 2, intermediate shaft 10, transition shaft 14 and output shaft 3 are rotatably connected to the gearbox body 1 and supported by bearings. The two ends of the guide rod 8 are fixedly connected to the gearbox body 1.

[0035] Comparison Appendix Figure 1 and attached Figure 5In this embodiment, the specific installation structure of the stepper motor 5 is as follows: a motor mounting groove 19 is provided on the gearbox body 1, a motor mounting surface 20 and a motor bearing seat 21 are provided on the gearbox body 1 corresponding to the motor mounting groove 19, a motor bearing for supporting the motor shaft is provided in the motor bearing seat 21, the front end face of the stepper motor 5 is in contact with the motor mounting surface 20, the motor shaft passes through the motor bearing and through the gearbox body 1, and the rear end of the stepper motor 5 is fixedly connected to the gearbox body 1 through the motor mounting seat 22.

[0036] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection of the present utility model.

Claims

1. A shifting structure for a motorcycle engine, comprising a gearbox body (1), wherein a drive shaft (2) connected to a crankshaft and an output shaft (3) connected to a load are disposed within the gearbox body (1), the drive shaft (2) and the output shaft (3) being connected via a shifting mechanism, the shifting mechanism comprising a gear set and a shift fork (4) for changing the connection state of the gear set, characterized in that, A stepper motor (5) is provided on the outside of the gearbox body (1). A crank (6) is mounted on the motor shaft of the stepper motor (5). One end of the crank (6) is hinged to a connecting rod (7), and the other end of the connecting rod (7) is hinged to a shift fork (4). The shift fork (4) is slidably mounted on a guide rod (8). The guide rod (8) is parallel to the drive shaft (2) and the output shaft (3). The stepper motor (5) drives the shift fork (4) to slide along the axial direction of the guide rod (8) to complete the shifting action.

2. The shifting structure of a motorcycle engine according to claim 1, characterized in that, The shift fork (4) is connected in the middle groove of the engagement sleeve (9). The engagement sleeve (9) is slidably mounted on the intermediate shaft (10). The first gear (11) and the second gear (12) are mounted on the intermediate shaft (10) on both sides of the engagement sleeve (9). The engagement sleeve (9) is driven by the shift fork (4) and can be selectively connected and transmitted with the first gear (11) and the second gear (12).

3. The shifting structure of a motorcycle engine according to claim 2, characterized in that, The inner ring of the meshing sleeve (9) is connected to the intermediate shaft (10) via a spline drive. The meshing sleeve (9) is connected to the first gear (11) and the second gear (12) via a matching protrusion and groove structure. The first gear (11) and the second gear (12) are rotatably connected to the intermediate shaft (10).

4. The shifting structure of a motorcycle engine according to claim 3, characterized in that, The drive shaft (2) is provided with a drive tooth (13), which meshes with the first gear (11) on the intermediate shaft (10) and the third gear (15) on the transition shaft (14). The intermediate shaft (10) is provided with an intermediate tooth (16), which meshes with the fourth gear (17) mounted on the output shaft (3). The transition shaft (14) is provided with a transition tooth (18), which meshes with the second gear (12) on the intermediate shaft (10).

5. The shifting structure of a motorcycle engine according to claim 4, characterized in that, The drive shaft (2), intermediate shaft (10), transition shaft (14), output shaft (3) and guide rod (8) are arranged in parallel. The two ends of the drive shaft (2), intermediate shaft (10), transition shaft (14) and output shaft (3) are rotatably connected to the gearbox body (1) and supported by bearings. The two ends of the guide rod (8) are fixedly connected to the gearbox body (1).

6. The shifting structure of a motorcycle engine according to claim 1, characterized in that, The gearbox body (1) is provided with a motor mounting slot (19). The gearbox body (1) corresponding to the motor mounting slot (19) is provided with a motor mounting surface (20) and a motor bearing seat (21). The motor bearing seat (21) is provided with a motor bearing that supports the motor shaft. The front end face of the stepper motor (5) is in contact with the motor mounting surface (20). The motor shaft passes through the motor bearing and through the gearbox body (1). The rear end of the stepper motor (5) is fixedly connected to the gearbox body (1) through a motor mounting seat (22).

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