Electric gear shifting mechanism of motor tricycle

Abstract

An electric gear shifting mechanism of a motor tricycle comprises a gearbox, one end of a shifting fork sliding shaft arranged in the gearbox extends out of the gearbox and is connected with an electric cylinder through a rotating arm assembly, the electric cylinder comprises a servo motor, a telescopic cylinder and a gearbox, a screw rod is supported in the telescopic cylinder through a bearing, and the servo motor is connected with the gearbox. The tail end of the screw extends into the gearbox to be fixedly connected with the driven gear, the screw is in threaded fit with a nut, the nut and the telescopic cylinder shell form circumferential limiting, the fixed end of a hollow telescopic rod is fixedly connected with the nut, the extending end of the hollow telescopic rod extends out of the telescopic cylinder shell to be connected with the rotating arm assembly, and a shaft of the servo motor extends into the gearbox. A driving gear arranged on the shaft is connected with a driven gear on the screw through an intermediate transmission gear arranged in the gearbox, the electric cylinder is installed on a support arranged on a gearbox shell, the telescopic cylinder is driven by the servo motor to work, and the shifting fork sliding shaft is driven by the rotating arm assembly to move to achieve gear shifting of the motor tricycle.

Description

Technical Field

[0001] The utility model relates to a gear shift mechanism for a tricycle or motorcycle, in particular to an electric gear shift mechanism for a tricycle. Background Art

[0002] The transmissions of existing three-wheeled motorcycles or three-wheeled electric vehicles usually use manual shifting. When changing gears, the driver needs to use one hand to pull the shift lever, causing the hand that pulls the shift lever to leave the steering handle. This not only increases the complexity of operation, but also brings serious driving safety hazards. Especially when driving at high speeds or in emergency situations, the response to vehicle control is slow, increasing the risk of accidents.

[0003] Furthermore, traditional manual shift systems typically use cables to control the movement of the shift fork shaft. Prolonged cable pulling can cause the cables to stretch, resulting in improper shifting and improper gear engagement, leading to gear clashing. Frequent gear clashing accelerates wear within the transmission, causing damage, significantly shortening its service life, and potentially causing permanent damage to the gears. Furthermore, improper shifting can cause abnormal noise, severely impacting the driver's driving experience.

[0004] For example, the rear axle transmission of a three-wheeled motorcycle disclosed in CN201003573Y has "a shift fork shaft with one end slidingly engaged with the front box body, and a front box cover connected to the front box body at the other end. The extended end extending out of the front box cover is connected to a control cable. By pulling the shift fork shaft with the control cable, the shift fork can easily drive the meshing gear to separate from the normally meshing driven gear and mesh with the reduction gear to achieve deceleration. After the control cable is relaxed, the spring causes the clutch gear to return to its original position and mesh with the driven gear to restore the original speed."

[0005] Although this technology simplifies the gear shifting operation to a certain extent, long-term reliance on the pulling of the cable will cause the control cable to stretch. The stretched control cable will cause the clutch gear and the reduction gear to not engage properly or not engage at all, resulting in noise or inability to shift gears. In addition, the combination of the clutch gear and the reduction gear is usually formed by the engagement of the pawls set on both sides of the clutch gear with the waist-shaped grooves corresponding to the reduction gear. When the pawls are not aligned with the waist-shaped grooves, pulling the control cable will cause the pawls to collide with the waist-shaped grooves, causing noise and reducing the service life of the transmission. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides an electric shift mechanism for a three-wheeled motorcycle. This mechanism utilizes a control switch to control a servo motor, driving the axial movement of a hollow telescopic rod within a telescopic cylinder. This mechanism, in turn, utilizes a rotating arm assembly to drive the shift fork's sliding shaft, enabling smooth electric shifting. This mechanism not only avoids the drawbacks of traditional cable systems but also improves shifting accuracy, reduces mechanical wear, and extends the life of the transmission, while also enhancing the driver's operating experience and driving safety.

[0007] The utility model is specifically achieved through the following technical solutions:

[0008] The electric shift mechanism of a three-wheeled motorcycle includes a gearbox, one end of a shift fork sliding shaft arranged in the gearbox extends out of the gearbox housing and is connected to the electric cylinder through a rotating arm assembly. The electric cylinder includes a servo motor, a telescopic cylinder, and a gearbox. A screw is supported by a bearing in the telescopic cylinder, and the tail end of the screw extends into the gearbox and is fixedly connected to the driven gear. A nut is threaded on the screw, and the nut and the telescopic cylinder housing form a circumferential limit. A hollow telescopic rod has a fixed end fixedly connected to the nut, and an extended end extends out of the telescopic cylinder housing to connect the rotating arm assembly. The shaft of the servo motor extends into the gearbox, and the driving gear arranged on the shaft is connected to the driven gear on the screw through an intermediate transmission gear arranged in the gearbox. The electric cylinder is installed on a bracket provided on the gearbox housing, and the telescopic cylinder is driven to work by the servo motor, and the shift fork sliding shaft is driven to move by the rotating arm assembly to realize the shifting of the three-wheeled motorcycle.

[0009] Preferably, the pivot arm assembly includes a tension spring, a pivot arm and a pivot arm bracket. The middle part of the pivot arm is hinged to the pivot arm bracket provided on the gearbox housing. One end of the pivot arm is clamped in a groove provided on the shift fork sliding shaft, and the other end is connected to the extended end of the hollow telescopic rod of the electric cylinder through a tension spring.

[0010] Preferably, the nut is in the shape of a stepped shaft, and an external thread is provided on the small diameter end of the nut, which is used to form a threaded match with the internal thread provided at the fixed end of the hollow telescopic rod, and a guide groove extending axially is provided on the circumference of the large diameter end of the nut, and the guide groove slides with the guide rail provided on the inner wall of the telescopic cylinder housing to form a circumferential limit for the nut; or, a tangent plane is provided on the circumference of the large diameter end of the nut, and the tangent plane slides with the inner wall of the telescopic cylinder housing to form a circumferential limit for the nut.

[0011] Preferably, a circular slider is provided at the head end of the screw rod, and the circular slider is slidably fitted in the inner hole of the hollow telescopic rod.

[0012] Preferably, a first buffer spring is hollowly sleeved on the screw rod, the first buffer spring is located at the rear end of the nut, and a second buffer spring is arranged at the front end of the screw rod, the second buffer spring is located in the inner hole of the hollow telescopic rod.

[0013] Preferably, the intermediate transmission gear is a double gear consisting of a large gear and a small gear, wherein the large gear is the driving tooth of the double gear, meshing with the driving gear of the servo motor, and the small gear is the driven tooth of the double gear, meshing with the driven gear at the tail end of the screw, and the intermediate transmission gear is arranged on an intermediate shaft arranged in the gearbox.

[0014] Preferably, the servo motor is connected to a button switch for controlling the gear position via a wire.

[0015] Preferably, the bracket is L-shaped, the short arm of the L-shaped bracket is fixedly mounted on the gear box of the electric cylinder, the upper part of the long arm is fixedly mounted on the servo motor and telescopic cylinder of the electric cylinder, and the lower part of the long arm is fixedly connected to the gearbox housing by bolts.

[0016] Preferably, the output gear shaft is supported by a bearing in the gearbox, the output teeth provided on the output gear shaft are constantly meshed with the differential reduction teeth, and a high-speed driven gear and a low-speed driven gear are clearance-fitted on the output gear shaft, and the high-speed driven gear and the low-speed driven gear are respectively meshed with the high-speed driving gear and the low-speed driving gear provided on the main shaft, and a spline hub is fixedly connected to the output gear shaft in the circumferential direction, and the spline hub is located between the high-speed driven gear and the low-speed driven gear, and an engagement sleeve for clutching is slidably fitted on the outer circle of the spline hub, and an annular groove is provided on the outer periphery of the engagement sleeve, and the shift fork provided on the shift fork sliding shaft is clamped in the annular groove provided on the outer periphery of the engagement sleeve, and the engagement sleeve is meshed with the high-speed driven gear or the low-speed driven gear by the shift fork.

[0017] Preferably, a compression spring is mounted on the shift fork on the shift fork sliding shaft and the shaft section extending from one end of the gearbox housing. The compression spring is located in the gearbox housing, with one end abutting against the gearbox housing and the other end abutting against the shift fork.

[0018] The beneficial effects of the utility model are as follows:

[0019] The control switch controls the servo motor to drive the axial movement of the hollow telescopic rod set in the telescopic cylinder, and drives the shift fork sliding shaft to move through the rotating arm assembly to realize the gear shifting of the three-wheeled motorcycle. The gear shifting can be realized by simply pressing the switch, without using the control cable to pull the shift fork shaft. On the one hand, electric shifting is realized, and on the other hand, it is avoided that the use of the control cable to pull the shift fork shaft causes the engagement of the coupling sleeve and the low-speed driven gear to be inadequate or unable to engage;

[0020] The rotating arm assembly is connected to the extended end of the hollow telescopic rod via a tension spring. The tension spring allows the engagement sleeve of the shift mechanism to be flexibly coupled to the gear gear, thereby avoiding direct collision when the engagement sleeve of the shift mechanism and the gear gear are not aligned, reducing noise and increasing the service life of the transmission.

[0021] A circular slider is provided at the head end of the screw, which can move axially inside the hollow telescopic rod to support the hollow telescopic rod;

[0022] The first buffer spring provided at the rear end of the nut and the second buffer spring provided at the front end of the circular slider are used to limit the axial movement of the nut on the screw rod, thereby preventing the excessive rotation of the arm device and excessive displacement of the fork sliding shaft caused by excessive extension and contraction of the hollow telescopic rod;

[0023] The electric cylinder is fixed to the gearbox housing through a bracket. The structural design is reasonable and compact, which helps to improve the overall stability of the system.

[0024] In summary, the utility model has the following advantages:

[0025] Electric gear shifting is easy to operate. The driver only needs to press the control switch to shift gears, avoiding the complicated operation of traditional manual cables and ensuring driving safety. It overcomes the shortcomings of the control cables and avoids problems such as inadequate gear shifting, gear clubbing and transmission damage caused by cable elongation, significantly improving gear shifting accuracy and transmission life. The tension spring realizes flexible gear shifting. The tension spring makes the coupling sleeve and the gear gear flexibly combined, avoiding collision when the coupling sleeve and the gear are not aligned, reducing noise generated during gear shifting and improving user comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural diagram of the utility model;

[0027] Figure 2 It is a schematic diagram of the external structure of the utility model. DETAILED DESCRIPTION

[0028] See also Figures 1 to 2 , an electric shift mechanism of a three-wheeled motorcycle, comprising a gearbox 11;

[0029] In this embodiment, the gearbox 11 supports an output gear shaft 21 through a bearing. The output teeth 22 provided on the output gear shaft 21 are constantly meshed with the differential reduction teeth 23. A high-speed driven gear 24 and a low-speed driven gear 25 are clearance-fitted on the output gear shaft 21. The high-speed driven gear 24 and the low-speed driven gear 25 are respectively meshed with the high-speed driving gear and the low-speed driving gear provided on the main shaft. A spline hub 26 is fixedly connected circumferentially on the output gear shaft 21. The spline hub 26 is located between the high-speed driven gear 24 and the low-speed driven gear 25. A clutch sleeve 27 is slidably fitted on the outer circle of the spline hub 26. An annular groove is provided on the outer periphery of the clutch sleeve 27. A shift fork 28 provided on the shift fork sliding shaft 1 is clamped in the annular groove provided on the outer periphery of the clutch sleeve 27. The shift fork 28 drives the clutch sleeve 27 to engage with the high-speed driven gear 24 or the low-speed driven gear 25.

[0030] A compression spring 29 is mounted on the shift fork 28 on the shift fork sliding shaft 11 and the shaft section extending from one end of the gearbox 11 housing. The compression spring 29 is located inside the gearbox 11 housing, with one end abutting against the gearbox 11 housing and the other end abutting against the shift fork 28. When the shift fork sliding shaft 11 is not subjected to external force, the compression spring 29 returns the shift fork 28 to its original position, acting as a return spring.

[0031] One end of the shift fork sliding shaft 1 extends out of the gearbox 11 housing and is connected to the electric cylinder 2 through a rotating arm assembly. The electric cylinder 2 includes a servo motor 3, a telescopic cylinder 4, and a gearbox 5. The servo motor 3 is connected to a button switch 30 for controlling the gear position through a wire. The button switch 30 is provided with a gear button that matches the gear position of the gearbox 11 of this embodiment. In this embodiment, two gears, "high speed" and "low speed", are provided. A screw rod 6 is supported by a bearing in the telescopic cylinder 4. The tail end of the screw rod 6 extends into the gearbox 5 and is fixedly connected to the driven gear 7. A nut 8 is threaded on the screw 6. The nut 8 forms a circumferential limit with the housing of the telescopic cylinder 4. A hollow telescopic rod 9 is fixedly connected to the nut 8 at its fixed end;

[0032] The nut 8 in this embodiment is in the shape of a stepped shaft, and an external thread is provided on the small-diameter end of the nut 8 for forming a threaded fit with the internal thread provided at the fixed end of the hollow telescopic rod 9. A guide groove extending axially is provided on the circumference of the large-diameter end of the nut 8, and the guide groove slides with the guide rail provided on the inner wall of the housing of the telescopic cylinder 4, so that the nut 8 is circumferentially limited and the nut 8 can move axially along the screw rod 6; alternatively, a tangent plane may be provided on the circumference of the large-diameter end of the nut 8, and the tangent plane slides with the inner wall of the housing of the telescopic cylinder 4, so that the nut 8 is circumferentially limited; or a slider is provided in the radial direction of the large-diameter section of the nut 8, and the slider cooperates with the slideway provided on the inner wall of the housing of the telescopic cylinder 4, so that the nut 8 is circumferentially limited;

[0033] In addition, a circular slider 17 is provided at the head end of the screw 6, and the circular slider 17 is slidably fitted in the inner hole of the hollow telescopic rod 9, and the circular slider 17 plays a supporting role for the hollow telescopic rod 9;

[0034] A first buffer spring 18 is hollowly sleeved on the screw rod 6. The first buffer spring 18 is located at the rear end of the nut 8. In this embodiment, the first buffer spring 18 is fixedly connected to the rear end of the nut 8. A second buffer spring 19 is provided at the front end of the screw rod 6. The second buffer spring 19 is located in the inner hole of the hollow telescopic rod 9. In this embodiment, the second buffer spring 19 is fixedly connected to the front end of the annular slider 17. The first buffer spring 18 and the second buffer spring 19 limit the axial movement distance of the hollow telescopic rod 9 on the screw rod 6 to prevent excessive extension and contraction of the hollow telescopic rod 9.

[0035] The extending end of the hollow telescopic rod 9 extends outward from the telescopic cylinder 4 housing and is connected to the rotating arm assembly. The direction in which the hollow telescopic rod 9 extends out of the telescopic cylinder 4 housing is the same as the direction in which the shift fork sliding shaft 11 extends out of the gearbox 11 housing. The shaft of the servo motor 3 extends into the gearbox 5, and the driving gear 10 provided on the shaft is connected to the driven gear 7 on the screw 6 through the intermediate transmission gear 20 provided in the gearbox 5. The electric cylinder 2 is mounted on a bracket 12 provided on the gearbox 11 housing. The bracket 12 of this embodiment is L-shaped, and the short arm of the L-shaped bracket 12 is fixedly mounted with the gearbox 5 of the electric cylinder 2. The servo motor 3 and the telescopic cylinder 4 of the electric cylinder 2 are fixedly mounted on the upper part of the long arm. The lower part of the long arm is fixedly connected to the gearbox 11 housing by bolts. The telescopic cylinder 4 is driven to work by the servo motor 3, and the shift fork sliding shaft 1 is driven to move by the rotating arm assembly to realize gear shifting of the three-wheeled motorcycle.

[0036] The intermediate transmission gear 20 in this embodiment is arranged on an intermediate shaft provided in the gearbox 11. The intermediate shaft can be a fixed shaft with a clearance fit with the intermediate transmission gear 20, or the intermediate shaft can be a rotating shaft fixedly connected to the intermediate transmission gear 20. The intermediate transmission gear 20 is a double gear consisting of a large gear and a small gear, wherein the large gear is the driving tooth of the double gear and meshes with the driving gear 10 of the servo motor 3, and the small gear is the driven tooth of the double gear and meshes with the driven gear 7 at the tail end of the screw 6;

[0037] The pivot arm assembly includes a tension spring 13, a pivot arm 14 and a pivot arm bracket 15. The middle part of the pivot arm 14 is hinged to the pivot arm bracket 15 provided on the housing of the gearbox 11. The pivot arm bracket 15 is exposed outside the electric cylinder 2 and the gearbox 11, which is convenient for subsequent maintenance and replacement of the telescopic spring 13 or the pivot arm 14. One end of the pivot arm 14 is clamped in the groove 16 provided on the shift fork sliding shaft 1, and the clamping part of the pivot arm 14 is circular, or the top end is provided with a flattened circle, thereby limiting the circumferential amplitude of the pivot arm 14 around the hinge. The other end of the pivot arm 14 is connected to the extended end of the hollow telescopic rod 9 of the electric cylinder 2 through the tension spring 13. The tension spring 13 can play a regulating role when the pawl of the coupling sleeve 27 in the gearbox and the waist-shaped groove of the gear gear fail to align, so that the coupling sleeve 27 flexibly cooperates with the gear gear, thereby reducing noise generation and improving the service life of the transmission.

[0038] Working principle:

[0039] When the driver presses the control switch, the control signal is transmitted to the servo motor 3. After receiving the signal, the servo motor 3 starts to operate and transmits power to the screw 6 through the gear box 5. The rotation of the screw 6 drives the nut 8 to move axially along the screw 6, thereby extending and retracting the hollow telescopic rod 9, and converting the rotational motion of the gear in the gear box 5 into linear motion of the hollow telescopic rod 9. The hollow telescopic rod 9 drives the rotating arm assembly 2 to rotate, thereby realizing the sliding of the shift fork sliding shaft 1, so that the shift fork 28 drives the coupling sleeve 27 to slide axially along the shift fork sliding shaft 1 and engage with the corresponding gear to complete the switching between high speed gear and low speed gear.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An electric gear shift mechanism for a three-wheeled motorcycle, comprising a gearbox (11), characterized in that: One end of the shift fork sliding shaft (1) provided in the gearbox (11) extends out of the gearbox (11) housing and is connected to the electric cylinder (2) through a rotating arm assembly. The electric cylinder (2) comprises a servo motor (3), a telescopic cylinder (4), and a gearbox (5). A screw (6) is supported by a bearing in the telescopic cylinder (4). The tail end of the screw (6) extends into the gearbox (5) and is fixedly connected to the driven gear (7). A nut (8) is threadedly engaged on the screw (6). The nut (8) and the telescopic cylinder (4) housing form a circumferential limit. A hollow telescopic rod (9) is fixed to the telescopic cylinder (4). The fixed end is fixedly connected to the nut (8), and the extended end extends out of the housing of the telescopic cylinder (4) to connect the rotating arm assembly. The shaft of the servo motor (3) extends into the gear box (5), and the driving gear (10) provided on the shaft is connected to the driven gear (7) on the screw (6) through the intermediate transmission gear (20) provided in the gear box (5). The electric cylinder (2) is installed on a bracket (12) provided on the housing of the gearbox (11). The telescopic cylinder (4) is driven to work by the servo motor (3), and the shift fork sliding shaft (1) is driven to move through the rotating arm assembly to realize the shifting of the three-wheeled motorcycle.

2. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: The swing arm assembly comprises a tension spring (13), a swing arm (14) and a swing arm bracket (15); the middle portion of the swing arm (14) is hinged to the swing arm bracket (15) provided on the housing of the gearbox (11); one end of the swing arm (14) is engaged in a groove (16) provided on the shift fork sliding shaft (1); and the other end is connected to the extended end of the hollow telescopic rod (9) of the electric cylinder (2) through the tension spring (13).

3. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: The nut (8) is in the shape of a stepped shaft, and an external thread is provided on the small diameter end of the nut (8) for forming a threaded fit with the internal thread provided on the fixed end of the hollow telescopic rod (9). A guide groove extending along the axial direction is provided on the circumference of the large diameter end of the nut (8), and the guide groove is slidably fitted with a guide rail provided on the inner wall of the shell of the telescopic cylinder (4), so that the nut (8) is formed into a circumferential limit; or a tangent plane is provided on the circumference of the large diameter end of the nut (8), and the tangent plane is slidably fitted with the inner wall of the shell of the telescopic cylinder (4), so that the nut (8) is formed into a circumferential limit.

4. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, wherein: A circular slider (17) is provided at the head end of the screw rod (6), and the circular slider (17) is slidably fitted in the inner hole of the hollow telescopic rod (9).

5. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: A first buffer spring (18) is hollowly sleeved on the screw rod (6), and the first buffer spring (18) is located at the rear end of the nut (8). A second buffer spring (19) is provided at the front end of the screw rod (6), and the second buffer spring (19) is located in the inner hole of the hollow telescopic rod (9).

6. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: The intermediate transmission gear (20) is a double gear consisting of a large gear and a small gear, wherein the large gear is the driving tooth of the double gear and meshes with the driving gear (10) of the servo motor (3), and the small gear is the driven tooth of the double gear and meshes with the driven gear (7) at the tail end of the screw (6). The intermediate transmission gear (20) is arranged on an intermediate shaft arranged in the gearbox (11).

7. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: The servo motor (3) is connected to a button switch (30) for controlling the gear position via a wire.

8. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, wherein: The bracket (12) is L-shaped, the short arm of the L-shaped bracket (12) is fixedly mounted with the gear box (5) of the electric cylinder (2), the upper part of the long arm is fixedly mounted with the servo motor (3) and the telescopic cylinder (4) of the electric cylinder (2), and the lower part of the long arm is fixedly connected to the housing of the gearbox (11) via bolts.

9. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: The gearbox (11) supports an output gear shaft (21) through a bearing. The output gear (22) provided on the output gear shaft (21) is constantly meshed with the differential reduction gear (23). A high-speed driven gear (24) and a low-speed driven gear (25) are clearance-matched on the output gear shaft (21). The high-speed driven gear (24) and the low-speed driven gear (25) are respectively meshed with the high-speed driving gear and the low-speed driving gear provided on the main shaft. The output gear shaft (21) is fixedly connected circumferentially. A spline hub (26) is located between the high-speed driven gear (24) and the low-speed driven gear (25). A clutch sleeve (27) is slidably fitted on the outer circle of the spline hub (26). An annular groove is provided on the outer periphery of the clutch sleeve (27). A shift fork (28) provided on the shift fork sliding shaft (1) is clamped in the annular groove provided on the outer periphery of the clutch sleeve (27). The shift fork (28) is used to shift the clutch sleeve (27) to engage with the high-speed driven gear (24) or the low-speed driven gear (25).

10. The electric shift mechanism for a three-wheeled motorcycle according to claim 1, characterized in that: A compression spring (29) is mounted on the shift fork (28) on the shift fork sliding shaft (11) and the shaft section extending from one end of the gearbox (11) housing. The compression spring (29) is located in the gearbox (11) housing, with one end abutting against the gearbox (11) housing and the other end abutting against the shift fork (28).

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