CN221835482U - A two-speed transmission structure for electric power-assisted bicycle - Google Patents

Abstract

A two-speed transmission structure for an electric power-assisted vehicle comprises a housing, an input shaft, an intermediate shaft, and an output shaft. The intermediate shaft is provided with a first-speed intermediate main gear, a first-speed intermediate sub-gear, a second-speed intermediate main gear, and a second-speed intermediate sub-gear. The input shaft is provided with a first-speed input gear and a clutch. The first-speed input gear meshes with the first-speed intermediate main gear. One end of a clutch seat of the clutch extends out of the clutch housing. The circumferential teeth are provided to form a second-speed input gear, which meshes with the second-speed intermediate main gear. The output shaft is provided with a first-speed one-way output gear, which meshes with the first-speed intermediate sub-gear. A second-speed one-way output gear is provided, which meshes with the second-speed intermediate sub-gear. The utility model has a simple structure and a compact size, and can achieve high torque through the first gear and high speed output through the second gear.

Description

A two-speed transmission structure for electric power-assisted bicycle

Technical Field

The utility model relates to the field of electric vehicles, in particular to a two-speed transmission structure for an electric power-assisted vehicle.

Background Art

Electric assisted bicycles are popular among consumers because of their low cost, flexible driving, and are particularly suitable for short-distance travel.

At present, the electric power-assisted bicycles produced on the market generally have the following shortcomings:

1. The matching transmission has a single-gear output. When driving at a high speed, the motor speed is too high, resulting in high energy consumption and a challenge to the heat dissipation of the motor;

2. When the matching transmission is designed with multiple gears, the thickness of the transmission along the length of the shaft is large, resulting in a larger volume and weight of the transmission, which is not conducive to the assembly and maintenance of the transmission.

Therefore, how to design a compact speed change structure with simple structure, large torque and high speed output is an urgent problem to be solved by those skilled in the art.

Summary of the invention

The utility model aims to provide a two-speed transmission structure for an electric power-assisted vehicle in view of the deficiencies in the prior art. The structure is simple and compact, and high torque can be achieved in the first gear and high speed output can be achieved in the second gear.

The technical scheme of the utility model is: a two-speed transmission structure for an electric power-assisted vehicle, comprising a housing, an input shaft, an intermediate shaft and an output shaft rotatably matched in the housing, wherein a first-speed intermediate main gear, a first-speed intermediate sub-gear, a second-speed intermediate main gear and a second-speed intermediate sub-gear are arranged on the intermediate shaft, the second-speed intermediate main gear and the second-speed intermediate sub-gear rotate coaxially, the first-speed intermediate main gear and the first-speed intermediate sub-gear are fixedly connected, and the idler rotates, one end of the input shaft protrudes out of the housing and is used to be connected with the output shaft of the motor, a first-speed input gear and a clutch are arranged on the input shaft, the first-speed input gear rotates coaxially and meshes with the first-speed intermediate main gear, the housing of the clutch rotates coaxially, the clutch seat of the clutch rotates idler, and one end of the clutch seat protrudes out of the housing, circumferentially provided with teeth to form a second-speed input gear, which meshes with the second-speed intermediate main gear, one end of the output shaft protrudes out of the housing and outputs power to the outside, a first-speed unidirectional output gear is arranged on the output shaft, which meshes with the first-speed intermediate sub-gear, and a second-speed unidirectional output gear is arranged, which meshes with the second-speed intermediate sub-gear.

The shell comprises a first half shell, a second half shell, and a connecting shell, wherein a partition is arranged in the connecting shell, the first half shell is installed on one side of the connecting shell, and the second half shell is installed on the other side of the connecting shell, and the combination forms a closed shell.

The input shaft and the intermediate shaft are rotatably supported on the first half shell, the partition plate, and the second half shell through bearings, and the output shaft is rotatably supported on the first half shell and the partition plate through bearings.

The first gear intermediate main gear and the second gear intermediate main gear are located between the connecting shell and the second half shell, the first gear intermediate sub-gear and the second gear intermediate sub-gear are located between the connecting shell and the first half shell, the first gear input gear and the clutch are located between the connecting shell and the second half shell, and the first gear input gear is close to the partition.

One end of the input shaft and the output shaft extend outward in the same direction, and both extend outward from the first half shell.

A shaft sleeve is arranged on the intermediate shaft, one end of the shaft sleeve is provided with teeth in the circumferential direction to form a first-gear intermediate auxiliary gear, and the other end of the shaft sleeve is provided with a keyway, and the first-gear intermediate main gear is fixed on the shaft sleeve through spline matching.

The intermediate shaft is provided with a keyway to form a keyway section, and a spiral groove to form a spiral groove section, the spiral groove is connected with the keyway, the shaft sleeve is loosely sleeved on the spiral groove section of the intermediate shaft, and the second gear intermediate main gear spline is matched with the keyway section of the intermediate shaft.

One end of the output shaft extends out of the housing and is circumferentially fixedly connected with an output gear. The output shaft also includes a pedal input shaft, which is rotatably mounted on the housing. A one-way input gear is arranged on the pedal input shaft and meshes with the output gear.

The clutch is a centrifugal clutch, and the clutch seat of the clutch extends out of the clutch housing toward the first gear input gear.

The above technical solution has the following beneficial effects:

1. A two-speed transmission structure for an electric power-assisted vehicle comprises a housing, an input shaft, an intermediate shaft, and an output shaft that are rotatably matched in the housing. The intermediate shaft is provided with a first-speed intermediate main gear, a first-speed intermediate sub-gear, a second-speed intermediate main gear, and a second-speed intermediate sub-gear. The second-speed intermediate main gear and the second-speed intermediate sub-gear rotate coaxially, that is, the two gears rotate simultaneously with the intermediate shaft. The first-speed intermediate main gear and the first-speed intermediate sub-gear are fixedly connected and rotated with an idle sleeve, that is, the two gears rotate simultaneously and are idle sleeved on the intermediate shaft. The input shaft is provided with a first-speed input gear and a clutch. The first-speed input gear rotates coaxially and meshes with the first-speed intermediate main gear, that is, the first-speed input gear rotates simultaneously with the input shaft. The outer shell of the clutch rotates coaxially, and the clutch seat of the clutch rotates with an idle sleeve, and one end of the clutch seat extends out of the outer shell, and teeth are arranged circumferentially to form a second-speed input gear, which meshes with the second-speed intermediate main gear. That is, when the clutch is in a disconnected state, the second-speed input gear is idle sleeved on the input shaft, and when the clutch is in a coupled state, the second-speed input gear rotates with the input shaft. The output shaft is provided with a one-way output gear of the first gear, meshing with the intermediate pinion of the first gear, and a one-way output gear of the second gear, meshing with the intermediate pinion of the second gear. When the speed of the input shaft is low, the clutch is in a disconnected state, and the input gear of the first gear drives the intermediate main gear of the first gear to drive the intermediate pinion of the first gear to rotate (idling on the intermediate shaft), thereby driving the output gear of the first gear to rotate and driving the output shaft to rotate at a low speed. Under this gear position, the torque output to the outside is large and the speed is low, which is a low-speed gear. When the speed of the input shaft is high, the clutch is in a coupled state, and the clutch seat of the clutch rotates with the housing, driving the intermediate main gear of the second gear, the intermediate shaft, and the intermediate pinion of the second gear to rotate (the speed of the intermediate shaft exceeds the speed of the intermediate main gear of the first gear and the intermediate pinion of the first gear), thereby driving the output gear of the second gear to rotate and driving the output shaft to rotate at a high speed (the speed of the output shaft exceeds the speed of the output gear of the first gear). Under this gear position, the torque output to the outside is small and the speed is high, which is a high-speed gear. When the input shaft does not rotate, the intermediate shaft remains stationary, and the output shaft can rotate in one direction (the first gear one-way output gear and the first gear one-way output gear remain stationary), it is neutral and can be used for unpowered gliding. This speed change structure is simple and compact, and can output different parameters of power according to different road conditions, effectively meeting the needs of drivers and avoiding excessive motor speed and excessive load.

2. The housing includes a first half shell, a second half shell, and a connecting shell. A partition is provided in the connecting shell. The first half shell is installed on one side of the connecting shell, and the second half shell is installed on the other side of the connecting shell. The combination forms a closed housing, which is convenient for assembly, disassembly and maintenance. The input shaft and the intermediate shaft are rotatably supported on the first half shell, the partition, and the second half shell through bearings, which improves the stability and deformation of the input shaft and the intermediate shaft.

3. The first gear input gear and the clutch are located between the connecting shell and the second half shell, and the first gear input gear is close to the partition. Since the clutch is usually large in size, the clutch is arranged on the outside of the first gear input gear, so that the first gear input gear and the second gear input gear can be installed in the middle of the input shaft, and then the first gear intermediate main gear and the second gear intermediate main gear are assembled in the middle of the intermediate shaft, so that the center of gravity of the speed change structure is centered, and the shaking condition of the speed change structure can be effectively improved, and the speed change structure can be made compact.

4. A keyway is arranged on the intermediate shaft to form a keyway section, and a spiral groove is arranged to form a spiral groove section. The spiral groove is connected with the keyway. The sleeve is loosely sleeved on the spiral groove section of the intermediate shaft. The second-gear intermediate main gear is splined on the keyway section of the intermediate shaft. Lubricating oil can flow through the keyway and the spiral groove to between the sleeve and the intermediate shaft to form lubrication and cooling, thereby effectively improving the service life of the sleeve (that is, the first-gear intermediate main gear and the first-gear intermediate sub-gear) and ensuring long-term normal operation of the transmission.

6. One end of the output shaft extends out of the housing, and is circumferentially fixedly connected with an output gear, and also includes a pedal input shaft, which is rotatably mounted on the housing, and a one-way input gear is arranged on the pedal input shaft, which meshes with the output gear. When the motor of the power output device cannot output power, the pedal input shaft can be driven to rotate by manual pedaling, thereby driving the output gear to rotate, which is used as an emergency. Under normal circumstances, the one-way input gear on the pedal input shaft is idle.

Further description is given below in conjunction with the accompanying drawings and specific implementation methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the cooperation of the present invention (the intersection of the gear and the shaft indicates circumferential fixation, the non-intersection of the gear and the shaft indicates idling, and the partial intersection of the gear and the shaft indicates unidirectional rotation).

In the accompanying drawings, 3 is a housing, 3a is a first half housing, 3b is a second half housing, 3c is a connecting housing, 4 is an input shaft, 5 is an intermediate shaft, 5a is a key groove section, 5b is a spiral groove section, 6 is a first gear intermediate main gear, 7 is a first gear intermediate sub-gear, 8 is a second gear intermediate main gear, 9 is a second gear intermediate sub-gear, 10 is a first gear input gear, 11 is a clutch, 11a is a housing, 11b is a clutch seat, 12 is a second gear input gear, 13 is a first gear one-way output gear, 14 is a second gear one-way output gear, 15 is a shaft sleeve, 16 is an output gear, 17 is a pedal input shaft, 18 is a one-way input gear, and 19 is an output shaft.

DETAILED DESCRIPTION

Referring to Fig. 1, a specific embodiment of a two-speed transmission structure for an electric power-assisted vehicle is shown. The two-speed transmission structure for an electric power-assisted vehicle comprises a housing 3, and an input shaft 4, an intermediate shaft 5, and an output shaft 19 rotatably fitted in the housing 3. Specifically, the housing 3 comprises a first half-shell 3a, a second half-shell 3b, and a connecting shell 3c, wherein a partition is provided in the connecting shell 3c, the first half-shell 3a is mounted on one side of the connecting shell 3c, and the second half-shell 3b is mounted on the other side of the connecting shell 3c, and the combination constitutes a closed housing, the input shaft 4 and the intermediate shaft 5 are rotatably supported on the first half-shell 3a, the partition, and the second half-shell 3b through bearings, that is, the input shaft and the intermediate shaft have three supporting points, and the output shaft 19 is rotatably supported on the first half-shell 3a and the partition through bearings, that is, the output shaft has two supporting points. The intermediate shaft 5 is provided with a first-gear intermediate main gear 6, a first-gear intermediate counter gear 7, a second-gear intermediate main gear 8, and a second-gear intermediate counter gear 9. The second-gear intermediate main gear 8 and the second-gear intermediate counter gear 9 rotate coaxially. In this embodiment, the second-gear intermediate counter gear is integrally formed on the intermediate shaft and is located in the first half shell. A shaft sleeve 15 is provided on the intermediate shaft 5 in an empty sleeve, and the shaft sleeve 15 is supported on the partition plate of the connecting shell 3c through a bearing. One end of the shaft sleeve is located between the first half shell and the connecting shell, and teeth are provided in the circumferential direction to form the first-gear intermediate counter gear 7. The other end of the shaft sleeve is located between the second half shell and the connecting shell, and a keyway is provided. The first-gear intermediate main gear 6 is fixed to the shaft sleeve through spline fitting. Specifically, a keyway is provided on the intermediate shaft 5 to form a keyway section 5a, and a spiral groove is provided to form a spiral groove section 5b. The spiral groove is connected to the keyway. The shaft sleeve 15 is empty sleeved on the spiral groove section 5b of the intermediate shaft. The second-gear intermediate main gear 8 is spline fitted on the keyway section 5a of the intermediate shaft and is located in the second half shell. One end of the input shaft 4 extends out of the first half shell for being connected to the motor output shaft. A first gear input gear 10 and a clutch 11 are arranged on the input shaft. The first gear input gear 10 rotates coaxially and meshes with the first gear intermediate main gear 6. Specifically, the first gear input gear is located between the connecting shell and the second half shell and is integrally formed on the input shaft. The outer shell 11a of the clutch 11 rotates coaxially, and the clutch seat 11b of the clutch 11 rotates in an idle manner. One end of the clutch seat 11b extends out of the outer shell 11a, and teeth are arranged circumferentially to form a second gear input gear 12, which meshes with the second gear intermediate main gear 8. In the present embodiment, the clutch 11 is a centrifugal clutch located in the second half shell. The outer shell 11a of the clutch is splined on the input shaft, and the clutch seat 11b of the clutch extends out of the outer shell 11a of the clutch toward the first gear input gear 10. One end of the output shaft 19 extends out of the first half shell, and is circumferentially fixedly connected with an output gear 16. A first-gear one-way output gear 13 is provided on the output shaft, meshing with the first-gear intermediate pinion 7. A second-gear one-way output gear 14 is provided, meshing with the second-gear intermediate pinion 9. The output shaft also includes a pedal input shaft 17, which is rotatably mounted on the housing 3. Obviously, it is necessary to assemble pedal crankshafts at both ends of the pedal input shaft respectively. A one-way input gear 18 is provided on the pedal input shaft 17, meshing with the output gear 16.

The two-speed transmission structure of the utility model can be used for electric power-assisted two-wheeled vehicles, three-wheeled vehicles and four-wheeled vehicles.

The working principle of the utility model is as follows: when the input shaft speed is low, the clutch is in a disconnected state, the first gear input gear drives the first gear intermediate main gear to drive the first gear intermediate sub-gear to rotate (idling on the intermediate shaft), and then drives the first gear output gear to rotate and drives the output shaft to rotate at a low speed. Under this gear, the torque output to the outside is large and the speed is low, which is a low-speed gear. When the input shaft speed is high, the clutch is in a coupled state, and the clutch seat of the clutch rotates with the housing, driving the second gear intermediate main gear, the intermediate shaft, and the second gear intermediate sub-gear to rotate (the speed of the intermediate shaft exceeds the speed of the first gear intermediate main gear and the first gear intermediate sub-gear), and then drives the second gear output gear to rotate and drives the output shaft to rotate at a high speed (the speed of the output shaft exceeds the speed of the first gear output gear). Under this gear, the torque output to the outside is small and the speed is high, which is a high-speed gear. When the motor of the power output device cannot output power, the pedal input shaft can be driven to rotate by manual pedaling, and then the output gear is driven to rotate, which is used as an emergency situation. Usually, the one-way input gear on the pedal input shaft is idle. When the input shaft does not rotate (the motor does not output power), the intermediate shaft remains stationary, and the output shaft can rotate in one direction (the first gear one-way output gear and the first gear one-way output gear remain stationary), which is neutral and can be used for unpowered gliding.

Claims (9)

1. A two-speed transmission structure for an electric power-assisted vehicle, characterized in that it comprises a housing (3), an input shaft (4), an intermediate shaft (5), and an output shaft (19) rotatably engaged in the housing (3), The intermediate shaft (5) is provided with a first-gear intermediate main gear (6), a first-gear intermediate auxiliary gear (7), a second-gear intermediate main gear (8), and a second-gear intermediate auxiliary gear (9); the second-gear intermediate main gear (8) and the second-gear intermediate auxiliary gear (9) rotate coaxially; the first-gear intermediate main gear (6) and the first-gear intermediate auxiliary gear (7) are fixedly connected and rotate in an idler manner; One end of the input shaft (4) extends out of the housing and is used to be connected to the output shaft of the motor. A first-gear input gear (10) and a clutch (11) are arranged on the input shaft (4). The first-gear input gear (10) rotates coaxially and meshes with the first-gear intermediate main gear (6). The housing (11a) of the clutch (11) rotates coaxially. The clutch seat (11b) of the clutch (11) rotates in an idle manner. One end of the clutch seat (11b) extends out of the housing (11a) and is provided with teeth in the circumferential direction to form a second-gear input gear (12) which meshes with the second-gear intermediate main gear (8). One end of the output shaft (19) extends out of the housing to output power to the outside. A first-gear one-way output gear (13) is provided on the output shaft to mesh with the first-gear intermediate pinion (7). A second-gear one-way output gear (14) is provided to mesh with the second-gear intermediate pinion (9). 2. The two-speed transmission structure for an electric power-assisted vehicle according to claim 1 is characterized in that: the shell (3) includes a first half shell (3a), a second half shell (3b), and a connecting shell (3c), a partition is provided in the connecting shell (3c), the first half shell (3a) is installed on one side of the connecting shell (3c), and the second half shell (3b) is installed on the other side of the connecting shell (3c), and the combination constitutes a closed shell. 3. The two-speed transmission structure for an electric power-assisted vehicle according to claim 2 is characterized in that: the input shaft (4) and the intermediate shaft (5) are rotatably supported on the first half shell (3a), the partition, and the second half shell (3b) through bearings, and the output shaft (19) is rotatably supported on the first half shell (3a) and the partition through bearings. 4. The two-speed transmission structure for an electric power-assisted vehicle according to claim 2 is characterized in that: the first-speed intermediate main gear (6) and the second-speed intermediate main gear (8) are located between the connecting shell (3c) and the second half shell (3b), the first-speed intermediate sub-gear (7) and the second-speed intermediate sub-gear (9) are located between the connecting shell (3c) and the first half shell (3a), the first-speed input gear (10) and the clutch (11) are located between the connecting shell (3c) and the second half shell (3b), and the first-speed input gear (10) is close to the partition. 5. The two-speed transmission structure for an electric power-assisted vehicle according to claim 2, characterized in that one end of the input shaft (4) and the output shaft (19) extend in the same direction and both extend out of the first half shell (3a). 6. The two-speed transmission structure for an electric power-assisted vehicle according to any one of claims 1 to 5 is characterized in that: a sleeve (15) is provided on the intermediate shaft (5) in an empty sleeve, one end of the sleeve is provided with teeth in the circumferential direction to form a first-speed intermediate auxiliary gear (7), and a keyway is provided at the other end of the sleeve, and the first-speed intermediate main gear (6) is fixed on the sleeve by spline fitting. 7. The second-speed transmission structure for an electric power-assisted vehicle according to claim 6 is characterized in that: a keyway is provided on the intermediate shaft (5) to form a keyway section (5a), a spiral groove is provided to form a spiral groove section (5b), the spiral groove is connected to the keyway, the shaft sleeve (15) is loosely sleeved on the spiral groove section (5b) of the intermediate shaft, and the second-speed intermediate main gear (8) is spline-fitted on the keyway section (5a) of the intermediate shaft. 8. The two-speed transmission structure for an electric power-assisted vehicle according to claim 1 is characterized in that one end of the output shaft (19) extends out of the housing (3) and is circumferentially fixedly connected to an output gear (16), and also includes a pedal input shaft (17), the pedal input shaft (17) is rotatably mounted on the housing (3), and a one-way input gear (18) is provided on the pedal input shaft (17) and meshes with the output gear (16). 9. The two-speed transmission structure for an electric power-assisted vehicle according to claim 1, characterized in that the clutch (11) is a centrifugal clutch, and the clutch seat (11b) of the clutch extends out of the clutch housing (11a) toward the first gear input gear (10).