CN216232815U

CN216232815U - Two-gear speed change system of electric motorcycle

Info

Publication number: CN216232815U
Application number: CN202122904993.3U
Authority: CN
Inventors: 赖建宏
Original assignee: Kwang Yang Motor Co Ltd
Current assignee: Kwang Yang Motor Co Ltd
Priority date: 2020-11-26
Filing date: 2021-11-24
Publication date: 2022-04-08
Anticipated expiration: 2031-11-24
Also published as: TWM620354U

Abstract

The utility model is provided with a driving shaft, an auxiliary shaft, a first gear power set, a second gear power set, a centrifugal clutch and a power output set; the auxiliary shaft and the driving shaft are arranged at intervals; the first gear power set and the second gear power set are arranged on the driving shaft and the auxiliary shaft; the centrifugal clutch is provided with an inner disc, an outer disc, a plurality of friction plates, a plurality of metal plates and a plurality of pushing units, wherein the inner disc is linked with the second-gear power set, the outer disc is linked with the driving shaft, each friction plate is combined with the outer disc, each metal plate is combined with the inner disc, a gap is reserved between each friction plate and each metal plate, and each pushing unit can push each friction plate and each metal plate; the power output group is combined with the auxiliary shaft; therefore, the two-gear speed changing system of the electric motorcycle can reduce the vibration during gear shifting and improve the gear shifting speed.

Description

Two-gear speed change system of electric motorcycle

Technical Field

The utility model relates to a two-gear speed changing system, in particular to a two-gear speed changing system of an electric motorcycle, which can reduce the vibration during gear shifting and improve the gear shifting speed.

Background

As shown in fig. 7, a two-speed transmission system of a conventional electric motorcycle mainly includes an electric motor 91, a first-speed gear set 92, a second-speed gear set 93, a flail clutch 94 and an output shaft 95, as disclosed in taiwan patent No. M392137. The electric motor 91 has a driving shaft 911, and the first gear set 92 has a first driving gear 921 and a first driven gear 922 which are engaged with each other. The second-speed gear set 93 is provided with a second driving gear 931 and a second driven gear 932 which are engaged with each other. The mass-throwing clutch 94 has an inner disc 941 and an outer disc 942, the inner disc 941 is coupled to the driving shaft 911 of the electric motor 91, and has a plurality of throwing masses 943 and a plurality of tension springs 944, each throwing mass 943 is coupled to the inner disc 941 by one of the tension springs 944, and the outer disc 942 surrounds the inner disc 941 and is coupled to the second driving gear 931 of the second-gear set 93. When the electric motor 91 is just started, the driving shaft 911 transmits power to the first gear set 92, the first gear set 92 transmits power to the output shaft 95 again, at this time, the inner disc 941 of the thrower clutch 94 rotates, the outer disc 942 does not rotate at rest, when the output shaft 95 gradually accelerates to a certain value, as shown in fig. 8, each thrower 943 of the inner disc 941 is thrown outward by centrifugal force, and abuts against the outer disc 942 shown in fig. 7, so that the outer disc 942 and the inner disc 941 rotate synchronously, and at this time, power is transmitted to the second gear set 93, the second gear set 93 transmits power to the output shaft 95 again, and the first gear set 92 does not transmit power any more.

However, the two-speed transmission system of the existing electric motorcycle has the following disadvantages:

1. in the process of the two-speed transmission system of the conventional electric motorcycle, when the first-speed gear set 92 is converted into the second-speed gear set 93 to transmit power to the output shaft 95, the outer disc 942 is accelerated from rest to the same rotational speed as the inner disc 941 in a short time, and the rotational speed difference between the outer disc 942 and the inner disc 941 is too large, so that a strong shock is generated during the engagement between the outer disc 942 and the inner disc 941, and since the outer disc 942 and the throwing blocks 943 rub against each other, part of the kinetic energy is converted into heat energy, resulting in energy dissipation.

2. The inner periphery of the outer disc 942 is spaced from the outer periphery of the inner disc 941, so that it takes a long time for the throwing blocks 943 to be thrown radially against the outer disc 942, which results in a disadvantage of insufficient shifting speed.

In summary, the two-speed transmission system of the existing electric motorcycle has the point that the improvement is needed.

SUMMERY OF THE UTILITY MODEL

[ problems to be solved by the utility model ]

The utility model mainly aims to provide a two-gear speed change system of an electric motorcycle, which mainly overcomes the defects and shortcomings that an outer disc of a swinging block clutch of the conventional two-gear speed change system of the electric motorcycle is accelerated to the same rotating speed as an inner disc from rest in a short time, strong vibration is generated in the process of jointing the outer disc and the inner disc due to too large rotating speed fall of the outer disc and the inner disc, partial kinetic energy is converted into heat energy due to the friction between the outer disc and each swinging block, energy is dissipated, and a distance is reserved between the inner peripheral surface of the outer disc and the outer peripheral surface of the inner disc, so that each swinging block spends a long time in the process of being swung out to abut against the outer disc, and further the speed of gear shifting is not fast enough.

[ means for solving problems ]

The utility model provides a two-gear speed change system of an electric motorcycle, which is arranged on the electric motorcycle, the electric motorcycle is provided with a width direction and a rear wheel, the electric motorcycle is provided with a central axis in the width direction, and the two-gear speed change system of the electric motorcycle is provided with:

a motor;

the driving shaft is combined with the motor and driven by the motor, and the driving shaft is provided with a first section part, a second section part and a third section part;

a counter shaft, the counter shaft and the driving shaft are arranged at intervals, and the counter shaft is provided with a first section part, a second section part and a third section part;

a first gear power set, which is arranged at the first section part of the driving shaft and the second section part of the auxiliary shaft;

a second gear power set, which is arranged at the second section part of the driving shaft and the third section part of the auxiliary shaft;

a centrifugal clutch, which is arranged at the third section of the driving shaft and is provided with an inner disc, an outer disc, a plurality of metal plates, a plurality of friction plates and a plurality of pushing units, wherein the inner disc is linked with the second-gear power set, the outer disc is linked with the driving shaft, a containing space is formed between the outer disc and the inner disc, the plurality of friction plates are combined with the outer disc and are arranged in the containing space, the plurality of metal plates are combined with the inner disc and are arranged in the containing space, each friction plate combined with the outer disc and each metal plate combined with the inner disc are separated and staggered in the containing space, a gap is formed between each friction plate and each metal plate, and the plurality of pushing units are arranged in the containing space; and

the power output group is driven by the auxiliary shaft to output power to the rear wheel and is at least combined with the first section part of the auxiliary shaft;

when the rotating speed of the driving shaft is higher than a certain value, the plurality of pushing units move outwards under the action of centrifugal force and further push the plurality of friction plates and the plurality of metal plates, so that each friction plate is abutted against each metal plate, the inner disc and the outer disc rotate at the same rotating speed, and the auxiliary shaft is driven by the second gear power set and transmits power to the power output set.

Further, the two-speed transmission system of the electric motorcycle as described above, wherein the first-speed power set is provided with a first driving gear and a first driven gear, the first driving gear is disposed on the first section of the driving shaft, and the first driven gear is disposed on the second section of the countershaft and engaged with the first driving gear; the two-gear speed change system of the electric motorcycle is provided with a one-way clutch which is arranged between the first driven gear and the second section part of the countershaft.

Still further, in the two-speed transmission system of an electric motorcycle as described above, the motor and the centrifugal clutch are respectively disposed on two sides of the central axis of the electric motorcycle.

Furthermore, the two-gear speed changing system of the electric motorcycle is characterized in that the power output group is also provided with an output shaft, and one end of the output shaft can be linked with the rear wheel; the central axis passes through the driving shaft, the auxiliary shaft and the output shaft.

Preferably, the two-gear speed changing system of the electric motorcycle as described above, wherein the two-gear power set is provided with a second driving gear and a second driven gear; the second driving gear can be rotatably sleeved on the second section part of the driving shaft in a sliding manner relative to the driving shaft, and the inner disc is combined with the second driving gear; the second driven gear is arranged at the third section part of the countershaft and is meshed with the second driving gear.

Preferably, the power output assembly is disposed in a housing of a motor transmission case, one end of the output shaft extends out of the housing, and the output shaft receives power from the auxiliary shaft, and the power is coupled to the rear wheel through one or more of a gear set, a belt or a chain, and drives the rear wheel to rotate.

Preferably, the two-speed transmission system of the electric motorcycle as described above, wherein the auxiliary shaft is partially disposed in a housing of a motor transmission case, the third section of the auxiliary shaft extends out of the housing, and the power output set drives the rear wheel to rotate via one or more of a gear set, a belt or a chain.

[ efficacy of the utility model ]

By the technical means, the effects obtained by the utility model are increased as follows:

1. when the electric motorcycle is driven by the first gear power set, the inner disc is driven by the second gear power set to have a pre-rotation speed instead of a static state, so that when the electric motorcycle is driven by the second gear power set, the speed drop between the inner disc and the outer disc is smaller than that between the outer disc and the inner disc of the two-gear speed change system of the conventional electric motorcycle, and the inner disc and the outer disc can be smoothly jointed relative to the outer disc and the inner disc of the two-gear speed change system of the conventional electric motorcycle when being jointed, thereby reducing the vibration during gear shifting.

2. As mentioned in point 1, the inner disc has a pre-rotation speed, so that the friction degree of the inner disc and the outer disc during the engagement can be reduced, and further, the situation of energy dissipation caused by the conversion of part of kinetic energy into heat energy can be reduced.

3. Compared with the prior electric motorcycle, the two-gear speed change system has the advantages that a distance is reserved between the inner peripheral surface of the outer disk of the throwing block clutch and the outer peripheral surface of the inner disk, so that each throwing block spends a long time in the process of being thrown out along the radial direction to abut against the outer disk; the process of jointing the inner disc and the outer disc of the two-gear speed change system of the electric motorcycle is realized by the abutting of each friction plate combined with the outer disc and each metal plate combined with the outer disc, and the jointing speed of the inner disc and the outer disc is high because the clearance between each friction plate and each metal plate is small, thereby improving the gear shifting speed.

4. As mentioned in point 3, the centrifugal clutch is smaller than the thrower clutch in volume, since the centrifugal clutch does not have to reserve enough space in the radial direction for throwing out the throwers.

5. The two-gear speed change system of the electric motorcycle can automatically shift gears without additionally arranging other gear shift mechanisms.

Drawings

FIG. 1 is a front view, partially in section, of a preferred embodiment of the present invention.

Fig. 2 is a partially enlarged front view of fig. 1.

Fig. 3 is a schematic top view of an electric motorcycle according to a preferred embodiment of the present invention.

Fig. 4 is a first schematic diagram of an implementation state of the preferred embodiment of the utility model.

Fig. 5 is a schematic diagram of the second implementation state of the preferred embodiment of the utility model.

Fig. 6 is a partially enlarged operation diagram of an implementation state of the preferred embodiment of the present invention.

Fig. 7 and 8 are schematic views of a two-speed transmission system of a conventional electric motorcycle.

List of reference numerals

10 motor

20 driving shaft

30 first gear power set

31 first driving gear

32 first driven gear

40 second gear power set

41 second drive gear

42 second driven gear

50 auxiliary shaft

60 one-way clutch

70 centrifugal clutch

71 inner disc

72 outer disc

73 holding space

74 friction plate

75 pushing unit

76 metal plate

80 power output group

81 output gear

82 final output gear

83 output shaft

91 electric motor

911 drive shaft

92 first gear set

921 first driving gear

922 the first driven gear

93 second gear set

931 second driving gear

932 second driven gear

94 clutch with throwing block

941 inner disc

942 outer disc

943 throwing block

944 extension spring

95 output shaft

C is central axis

A1 first segment

A2 second segment

A3 third segment

B1 first segment part

B2 second segment part

B3 third section.

Detailed Description

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the utility model, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.

A preferred embodiment of the two-speed transmission system of an electric motorcycle according to the present invention is shown in fig. 1 and 3, which is provided on an electric motorcycle having a width direction and a rear wheel, the electric motorcycle having a central axis C in the width direction, the two-speed transmission system of the electric motorcycle including a motor 10, a driving shaft 20, a first-speed power group 30, a second-speed power group 40, a counter shaft 50, a one-way clutch 60, a centrifugal clutch 70 and a power output group 80, wherein:

as shown in fig. 1 to 3, the motor 10 is disposed on the electric motorcycle, the driving shaft 20 is coupled to the motor 10, the driving shaft 20 is driven by the motor 10, and the driving shaft 20 has a first section a1, a second section a2 and a third section A3.

As shown in fig. 1 and 2, the first gear power set 30 is disposed in the first section a1 of the driving shaft 20, and is provided with a first driving gear 31 and a first driven gear 32. The first drive gear 31 is provided at the first section a1 of the drive shaft 20; further, the first drive gear 31 is integrally formed on the first section a1 of the drive shaft 20. The first driven gear 32 is engaged with the first drive gear 31.

As shown in fig. 1 and 2, the second-gear power set 40 is disposed in the second section a2 of the driving shaft 20, spaced apart from the first-gear power set 30, and the second-gear power set 40 has a second driving gear 41 and a second driven gear 42. The second driving gear 41 is rotatably and slidably sleeved on the second section a2 of the driving shaft 20 relative to the driving shaft 20, and is spaced from the first driving gear 31; further, a needle bearing is disposed between the second driving gear 41 and the driving shaft 20, so that the second driving gear 41 can smoothly rotate relative to the driving shaft 20. The second driven gear 42 is engaged with the second driving gear 41 and is spaced apart from the first driven gear 32.

As shown in fig. 1 and 2, the counter shaft 50 is spaced apart from the driving shaft 20, and is provided with a first section B1, a second section B2 and a third section B3, and the driving shaft 20 passes through the first driven gear 32 of the first-gear power set 30 and the second driven gear 42 of the second-gear power set 40, such that the first driven gear 32 of the first-gear power set 30 is disposed on the second section B2 of the counter shaft 50, and the second driven gear 42 of the second-gear power set 40 is disposed on the third section B3 of the counter shaft 50. The one-way clutch 60 is disposed inside the first driven gear 32 and sleeved on the second section B2 of the counter shaft 50. The counter shaft 50 can be driven by the one-way clutch 60 to rotate synchronously with the first driven gear 32 or driven by the second driven gear 42 to rotate synchronously with the second driven gear 42.

As shown in fig. 1 to 3, the centrifugal clutch 70 and the motor 10 are respectively disposed on two sides of the central axis C of the electric motorcycle, the centrifugal clutch 70 is disposed on the third section a3 of the driving shaft 20, and is combined with the second driving gear 41 of the second gear power set 40, and is provided with an inner disc 71, an outer disc 72, a plurality of friction plates 74, a plurality of metal plates 76 and a plurality of abutting units 75. The inner disc 71 is coupled and interlocked with the second driving gear 41, and the inner disc 71 and the second driving gear 41 have the same rotation speed. The outer disc 72 surrounds the inner disc 71, the inner circumferential surface of the outer disc 72 and the outer circumferential surface of the inner disc 71 are spaced, so that an accommodating space 73 is formed between the outer disc 72 and the inner disc 71, the outer disc 72 is combined with the driving shaft 20 and is arranged in a linkage manner, and the outer disc 72 and the driving shaft 20 have the same rotating speed. The plurality of friction plates 74 are combined with the outer disc 72 and are disposed in the accommodating space 73. The plurality of metal plates 76 are combined with the inner disc 71 and arranged in the accommodating space 73, the friction plates 74 combined with the outer disc 72 and the metal plates 76 combined with the inner disc 71 are arranged in the accommodating space 73 at intervals and in a staggered manner, and a gap is formed between the metal plates 76 of the friction plates 74. The plurality of pushing units 75 are annularly spaced in the accommodating space 73, and when the outer disc 72 does not rotate, each pushing unit 75 only abuts against one of the friction plates 74, and does not press the friction plate 74.

As shown in fig. 1 and 3, in the preferred embodiment of the present invention, the central axis C of the electric motorcycle passes through the driving shaft 20, the counter shaft 50 and the output shaft 83.

As shown in fig. 1 and 2, the power output group 80 is coupled to at least the first section B1 of the counter shaft 50, and is provided with an output gear 81, a final output gear 82 and an output shaft 83. The output gear 81 is coupled to the counter shaft 50. The final output gear 82 meshes with the output gear 81. One end of the output shaft 83 is coupled with the final output gear 82.

As shown in fig. 1 and 3, the first gear power pack 30, the second gear power pack 40, the countershaft 50, the one-way clutch 60, the centrifugal clutch 70, and the power take-off 80 are all disposed in a housing of a motor transmission. The end of the output shaft 83 remote from the final output gear 82 extends out of the housing, and the output shaft 83 receives power from the auxiliary shaft 50, and the power is transmitted through one or more of a gear set, a belt or a chain to drive the rear wheel and drive the rear wheel to rotate.

In other preferred embodiments, the third section B3 of the auxiliary shaft 50 extends out of the housing, and the power output assembly 80 is disposed outside the housing and directly connects to the rear wheel via one or more of a gear set, a belt or a chain, and drives the rear wheel to rotate.

As shown in fig. 4, when the two-speed transmission system of the electric motorcycle of the present invention is initially operated, the driving shaft 20 is driven by the motor 10, the first driving gear 31 of the first-speed power group 30 and the outer disc 72 of the centrifugal clutch 70 are driven to rotate, the first driving gear 31 then transmits power to the first driven gear 32, the counter shaft 50 is driven by the one-way clutch 60 to rotate synchronously with the first driven gear 32, that is, the counter shaft 50 is driven by the first-speed power group 30 and transmits power to the rear wheel of the electric motorcycle via the power output group 80, at this time, the electric motorcycle is driven by the first-speed power group 30, and at the same time, the second driven gear 42 rotates together with the counter shaft 50 and transmits power to the inner disc 71 via the second driving gear 41 to rotate the inner disc 71, whereby the structural configuration is such that, when the electric motorcycle is driven by the first-speed power group 30, the inner disc 71 has a pre-rotation speed rather than a stationary state.

As shown in fig. 5 and 6, when the driving shaft 20 is driven by the motor 10 to accelerate to a certain value, the plurality of pushing units 75 are moved outward by centrifugal force, and further push the plurality of friction plates 74 and the plurality of metal plates 76, so that there is no gap between each friction plate 74 and each metal plate 76 is abutted, at this time, the inner disc 71 rotates at the same rotation speed as the outer disc 72, the one-way clutch 60 separates from the countershaft 50 due to the over rotation speed, so that the first driven gear 32 is in an idle rotation state, at this time, the driving shaft 20 drives the outer disc 72 and the inner disc 71 to rotate at the same rotation speed, the inner disc 71 sequentially transmits power to the second driving gear 41 and the second driven gear 42, the second driven gear 42 transmits power to the countershaft 50, that is, the countershaft 50 is driven by the second gear group 40, and the countershaft 50 finally transmits power to the rear wheel of the electric motorcycle via the power output group 80, the electric motorcycle is driven by the second gear power pack 40 at this time.

1. when the electric motorcycle is driven by the first gear power set 30, the inner disc 71 is driven by the second gear power set 40 to have a pre-rotation speed rather than a static state, so that when the electric motorcycle is driven by the second gear power set 40, the speed drop between the inner disc 71 and the outer disc 72 is smaller than the speed drops of the outer disc 942 and the inner disc 941 of the two-gear transmission system of the conventional electric motorcycle, and the inner disc 71 and the outer disc 72 are smoothly engaged with each other relative to the outer disc 942 and the inner disc 941 when engaged, thereby reducing the shock during shifting.

2. As mentioned in point 1, since the inner disc 71 has a pre-rotation speed, the degree of friction between the inner disc 71 and the outer disc 72 during the engagement process can be reduced, and further, the situation of energy dissipation caused by the conversion of part of kinetic energy into heat energy can be reduced.

3. Compared with the conventional two-gear transmission system of the electric motorcycle, the distance between the inner peripheral surface of the outer disk 942 of the thrower clutch 94 and the outer peripheral surface of the inner disk 941 is relatively long, so that it takes a relatively long time for each thrower 943 to be thrown radially to abut against the outer disk 942; the process of jointing the inner disk 71 and the outer disk 72 of the two-gear speed changing system of the electric motorcycle is realized by abutting each friction plate 74 combined with the outer disk 72 and each metal plate 76 combined with the outer disk 72, and the jointing speed of the inner disk 71 and the outer disk 72 is fast because the clearance between each friction plate 74 and each metal plate 76 is small, thereby improving the gear shifting speed.

4. As described in point 3, since the centrifugal clutch 70 does not have to reserve enough space in the radial direction for the throws 943 to throw, the centrifugal clutch 70 is smaller than the throws clutch 94.

In summary, the embodiments and examples of the present invention are described only to solve the problems, and the scope of the present invention is not limited thereto. It is intended that all variations and modifications which are consistent with the meaning of the claims or equivalent to the scope of the present invention are covered by the scope of the present invention.

Claims

1. The utility model provides an electric motorcycle car's two grades of speed change systems which characterized in that, it is located an electric motorcycle car, electric motorcycle car has a width direction and a rear wheel, electric motorcycle car has a axis in the width direction, electric motorcycle car's two grades of speed change systems is equipped with:

a motor;

the driving shaft is combined with the motor and driven by the motor, and is provided with a first section part, a second section part and a third section part;

the auxiliary shaft is arranged at intervals with the driving shaft and is provided with a first section part, a second section part and a third section part;

a first-gear power set disposed at the first section of the drive shaft and the second section of the countershaft;

a second-gear power set disposed at the second section of the drive shaft and the third section of the countershaft;

a centrifugal clutch, which is disposed at the third section of the driving shaft and is provided with an inner disc, an outer disc, a plurality of friction plates, a plurality of metal plates and a plurality of pushing units, wherein the inner disc is linked with the second-gear power set, the outer disc is linked with the driving shaft, a containing space is formed between the outer disc and the inner disc, the plurality of friction plates are combined with the outer disc and are disposed in the containing space, the plurality of metal plates are combined with the inner disc and are disposed in the containing space, the friction plates combined with the outer disc and the metal plates combined with the inner disc are spaced and staggered in the containing space, a gap is formed between each friction plate and each metal plate, and the pushing units are disposed in the containing space; and

a power take-off group coupled to at least the first section of the countershaft;

when the rotating speed of the driving shaft is higher than a certain value, the plurality of pushing units move towards the outer side under the action of centrifugal force and further push the plurality of friction plates and the plurality of metal plates, so that each friction plate is abutted against each metal plate, the inner disc and the outer disc rotate at the same rotating speed, and at the moment, the auxiliary shaft is driven by the second gear power group and transmits power to the power output group.

2. The two-speed transmission system for electric motorcycles as claimed in claim 1, wherein said first speed power group is provided with a first drive gear provided at said first section portion of said drive shaft and a first driven gear provided at said second section portion of said counter shaft and meshed with said first drive gear; the two-gear speed change system of the electric motorcycle is provided with a one-way clutch, and the one-way clutch is arranged between the first driven gear and the second section part of the countershaft.

3. The two-speed transmission system for an electric motorcycle according to claim 1 or 2, wherein the motor and the centrifugal clutch are respectively provided on both sides of the central axis of the electric motorcycle.

4. The two-speed transmission system of the electric motorcycle according to claim 1 or 2, wherein the power output unit is further provided with an output shaft, and one end of the output shaft is used for driving the rear wheel; the central axis passes through the drive shaft, the counter shaft and the output shaft.

5. The two-speed transmission system of an electric motorcycle according to claim 1 or 2, wherein the second-speed power group is provided with a second driving gear and a second driven gear; the second driving gear can be rotatably sleeved on the second section part of the driving shaft in a sliding manner relative to the driving shaft, and the inner disc is combined with the second driving gear; the second driven gear is provided in the third section of the counter shaft and is meshed with the second drive gear.

6. The two speed transmission system of electric motorcycle of claim 3, wherein the second speed power set is provided with a second driving gear and a second driven gear; the second driving gear can be rotatably sleeved on the second section part of the driving shaft in a sliding manner relative to the driving shaft, and the inner disc is combined with the second driving gear; the second driven gear is provided in the third section of the counter shaft and is meshed with the second drive gear.

7. The two speed transmission system of electric motorcycle of claim 4, wherein the second speed power set is provided with a second driving gear and a second driven gear; the second driving gear can be rotatably sleeved on the second section part of the driving shaft in a sliding manner relative to the driving shaft, and the inner disc is combined with the second driving gear; the second driven gear is provided in the third section of the counter shaft and is meshed with the second drive gear.

8. The two speed transmission system of electric motorcycle of claim 4, wherein the power take-off assembly is disposed in a housing of a motor transmission case, one end of the output shaft extends out of the housing, and the output shaft receives power from the auxiliary shaft, and the power is transmitted to the rear wheel through one or more of a gear set, a belt or a chain to drive the rear wheel to rotate.

9. The two speed transmission system of electric motorcycle of claim 1, wherein the auxiliary shaft is partially disposed in a housing of a motor transmission case, the third section of the auxiliary shaft extends out of the housing, and the power output group is disposed outside the housing, and drives the rear wheel to rotate via one or more of a gear set, a belt or a chain.