Electric bicycle mid-mounted motor
By designing hollow shell 2 and rotating paddles in the middle motor of the electric bicycle, the efficient heat dissipation of the motor is achieved by mixing wind and lubricating oil, and the problem of unsatisfactory heat dissipation of the middle motor in high temperature environments is solved.
Patent Information
- Application Number
- CN202411931636.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-04-04
AI Technical Summary
The electric bicycle mid-mounted motor has poor heat dissipation effect during long-distance travel or high-temperature environments, making it difficult to effectively reduce the motor temperature.
A central motor including housing two is designed. The housing two is a hollow structure, equipped with a speed reduction block and a rotating paddle, which dissipates heat by wind power, and assists heat dissipation through stirring of lubricating oil and circulation of rainwater.
Through the stirring of wind and lubricating oil, the flexibility and efficiency of motor heat dissipation are achieved, especially in high temperatures or long-distance travel, which effectively reduces the motor temperature.
Smart Images
Figure CN119765758A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of mid-mounted motors, in particular to a mid-mounted motor for an electric bicycle. Background Art
[0002] The popularity of electric bicycles is increasing. Their convenience and low-carbon attributes are irreplaceable by other means of transportation. The motors on electric bicycles can provide riders with additional pedal assist, making riding more labor-saving. As the core component of electric bicycles, different motors will also affect the performance of electric bicycles. The motors on the market are mainly divided into two categories: hub motors and mid-mounted motors.
[0003] The mid-drive motor is a drive system that places the electric motor in the middle of the vehicle. The motor is located at the bottom bracket between the center pedals of the bicycle, and the crank is directly connected to the mid-drive motor. The mid-drive motor is integrated into the frame of the electric bicycle, rather than being a separate unit like a hub motor. It does not directly power the wheels like a hub motor, but instead needs to be powered by the bicycle's transmission system. The motor turns the crank and chain ring, and powers the rear wheel through the chain. This design provides unique advantages for electric motorcycles, including better weight distribution, higher efficiency, and more optimized power output. Therefore, electric bicycles are the first choice for many people who love sports or travel.
[0004] Unlike other motors, the mid-mounted motor of an electric bicycle needs to be exposed to the external environment for a long time, so it needs strict protection to avoid daily impact and rain intrusion. The casing of the mid-mounted motor is generally designed to be thick and hard, and the heat dissipation of the mid-mounted motor also relies more on the thermal conductivity of the casing. When encountering long-distance travel or high-temperature environment, the heat dissipation effect is not ideal. Summary of the invention
[0005] The purpose of the present invention is to provide a mid-mounted motor for an electric bicycle to solve the problems raised in the above background technology.
[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an electric bicycle mid-mounted motor includes a motor body, the outer cover of the motor body is provided with a shell one, the shell one is used to assemble the motor body and provide basic protection for it, the motor body includes a transmission module and an electromagnetic module, wherein the transmission module is provided with a transmission shaft rotatably arranged through a bearing, and both ends of the transmission shaft extend out of the two side surfaces of the shell one, the electromagnetic module is used for electromagnetic induction, and is the main heating structure, and the electromagnetic module has a built-in temperature sensor for detecting the internal temperature state.
[0007] According to the above technical solution, a shell 2 is provided on the outer cover of shell 1, shell 2 is a hollow structure and the space on one side of the interior corresponds to the position of the electromagnetic module, an inlet component and an outlet component are respectively provided on the front and rear sides of shell 2, an opening and closing component is provided on the upper side of shell 2, the inlet component includes a rotating rod 1, a spring clip 1, a spring clip 2, a driver 1 and a pressure sensor, wherein the rotating rod 1 is rotatably arranged on the inner wall of one side of shell 2, one end of the spring clip 1 and the spring clip 2 are respectively connected to the rotating rod 1, the driver 1 is connected to the rotating rod 1, and the pressure sensor is arranged on the rotating rod 1 for detecting the wind pressure state blowing toward the surface of the rotating rod 1.
[0008] According to the above technical solution, a plurality of deceleration blocks are arranged on the upper side of the shell 2 relative to the electromagnetic module. The deceleration blocks are of S-shaped structure and have a plurality of scattering holes. The scattering holes are used to scatter the passing high-speed airflow and slow down the gas flow rate.
[0009] According to the above technical solution, the outlet component includes a screw rod 1, a lifting plate and a driver 2, wherein the screw rod 1 is rotatably arranged on the inner wall of the shell 2, the lifting plate is passed through the screw rod 1 and threadedly matched with the screw rod, the driver 2 is connected to one end of the screw rod 1, and the shell 2 is correspondingly provided with a window 2 and a slide groove for the lifting plate to slide.
[0010] According to the above technical solution, an arc-shaped groove is provided on the inner wall of the upper side of the second shell, and a plurality of through holes penetrating vertically are provided on the upper side of the second shell corresponding to the position of the arc-shaped groove.
[0011] According to the above technical solution, the opening and closing assembly includes a telescopic plate, a second screw rod, a set of transmission gears and a third driver, wherein the telescopic plate is slidably matched with the arc groove, the second screw rod is inserted into the telescopic plate and threadedly matched with it, the transmission gears respectively connect the second screw rod and the third driver, and the third driver is fixed on the inner wall of the second shell.
[0012] According to the above technical solution, an auxiliary component is arranged in the shell body 2 relative to the front side of the shell body 1, and the auxiliary component includes a rotating rod 2, a plurality of blades, a driving gear, a plurality of intermediate gears, a driven gear and a rotating paddle, wherein the rotating rod 2 is rotatably arranged on the shell body 2 and one end passes through the lower side of the shell body 2, the blades are arranged on the rotating rod 2 at intervals, the driving gear is sleeved on the end of the rotating rod 2 extending out of the shell body 2, the intermediate gear is rotatably arranged at the bottom of the shell body 2 and cooperates with the driving gear, one end of the rotating paddle is rotatably arranged on the shell body 2, and the driven gear is sleeved on the end of the rotating paddle and cooperates with the intermediate gear.
[0013] According to the above technical solution, the rotating impeller outer shell is provided with a lubricating oil storage cylinder, which is fixed to the bottom of the second shell and is used to store lubricating oil and provide lubrication for the transmission shaft through an external delivery system.
[0014] According to the above technical solution, the rotating paddle is a hollow structure and is connected from top to bottom. A number of branches are arranged on the circumference of the rotating paddle. Each branch is a hollow structure and is connected to the rotating paddle. The rotating paddle and each branch hollow structure form a heat dissipation channel. The second shell is provided with corresponding holes in cooperation with the upper opening of the rotating paddle, and the lubricating oil storage cylinder is provided with corresponding holes in cooperation with the lower opening of the rotating paddle.
[0015] According to the above technical solution, a mid-mounted motor is installed on an electric bicycle, which includes a frame, wheels, cranks, pedals, belts and a driving pulley. The motor body is connected to the frame and the inlet assembly faces the front end of the frame. The wheels are rotatably arranged on the front and rear sides of the frame respectively. The crank is connected to both ends of the transmission shaft. The pedals are installed on the corresponding crank. The belt connects the driving pulley and the rear wheel, and the driving pulley is sleeved on one side of the transmission shaft.
[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention, by providing a second shell, can utilize the wind force during riding to dissipate the heat for the mid-mounted motor that has a heat dissipation requirement, and at the same time divide the wind according to different wind forces. When the wind speed is too high, the speed reduction block is used to break up the wind, and when the wind speed is moderate, the contact area with the shell one is increased, thereby improving the flexibility of the heat dissipation of the motor; by providing an auxiliary component, the lubricating oil can be stirred by the wind force, and at the same time, the heat is dissipated by wind pressure and rainwater, thereby improving the lubrication quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the structure of the mid-mounted motor of the present invention; Figure 2 is a partial schematic diagram of the mid-mounted motor of the present invention; Figure 3 is a second schematic diagram of the housing of the present invention; Figure 4 It is a schematic diagram of the inlet assembly, outlet assembly and opening and closing assembly of the present invention; Figure 5 The present invention Figure 4 A magnified schematic diagram of area A; Figure 6 is a cross-sectional view of an outlet assembly of the present invention; Figure 7 is a partial cross-sectional view of the housing of the present invention; Figure 8 is a partial cross-sectional view of a stirring paddle of the present invention; Fig. 9 It is a schematic diagram of the structure of the electric bicycle of the present invention; In the figure: 1. Shell 1; 2. Transmission shaft; 3. Shell 2; 31. Speed reduction block; 311. Breakup hole; 32. Slide; 33. Arc groove; 34. Through hole; 4. Inlet assembly; 41. Rotating rod 1; 42. Shrapnel 1; 43. Shrapnel 2; 44. Driver 1; 45. Buckle; 5. Outlet assembly; 51. Screw 1; 52. Lifting plate; 53. Driver 2; 6. Opening and closing assembly; 61. Telescopic plate; 62. Screw 2; 63. Transmission gear; 64. Driver 3; 71. Rotating rod 2; 72. Blade; 73. Driving gear; 74. Intermediate gear; 75. Driven gear; 76. Rotating paddle; 761. Branch; 762. Heat dissipation channel; 8. Lubricating oil storage cylinder; 91. Frame; 92. Wheel; 93. Crank; 94. Pedal; 95. Belt; 96. Drive pulley. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] See also Figure 1-9 The present invention provides a technical solution: a mid-mounted motor for an electric bicycle, comprising a motor body, a housing 1 being provided on the outer cover of the motor body, the housing 1 being used to assemble the motor body and provide basic protection for the motor body, the motor body comprising a transmission module and an electromagnetic module, wherein the transmission module is provided with a transmission shaft 2 rotatably through a bearing, the two ends of the transmission shaft 2 extending out of the two side surfaces of the housing 1, the electromagnetic module being used for electromagnetic induction and being the main heating structure, the electromagnetic module having a built-in temperature sensor for detecting the internal temperature state; The outer cover of the shell 1 is provided with a shell 2 3, the shell 2 3 is a hollow structure and the space on one side of the interior corresponds to the position of the electromagnetic module, the front and rear sides of the shell 2 3 are respectively provided with an inlet component 4 and an outlet component 5, the upper side of the shell 2 3 is provided with an opening and closing component 6, the inlet component 4 includes a rotating rod 1 41, a spring piece 1 42, a spring piece 2 43, a driver 1 44 and a pressure sensor, wherein the rotating rod 1 41 is rotatably arranged on the inner wall of one side of the shell 2 3, one end of the spring piece 1 42 and the spring piece 2 43 are respectively connected to the rotating rod 1 41, the driver 1 44 is connected to the rotating rod 1 41, and the pressure sensor is arranged on the rotating rod 1 41 for detecting the wind pressure state blowing toward the surface of the rotating rod 1 41; The shell 2 3 is provided with a plurality of deceleration blocks 31 on the upper side of the electromagnetic module. The deceleration blocks 31 are of S-shaped structure and have a plurality of scattering holes 311. The scattering holes 311 are used to scatter the high-speed airflow passing through and slow down the gas flow rate.
[0020] The supplementary description based on the above structure is as follows: the spring piece 1 42 corresponds to the space where the shell 1 is located, the spring piece 2 43 corresponds to the space on the other side of the shell 2 3, and the spring piece 1 42 and the spring piece 2 43 are provided with a buckle 45 at the other end. The spring piece 1 42 and the spring piece 2 43 are made of a material with good elasticity and have a certain curvature in shape. The shell 2 3 cooperates with the inlet component 4 to open a corresponding window 1, and the buckle 45 is buckled at the edge of the window 1; when the driver 1 44 drives the rotating rod 1 41 to rotate forward, the rotating rod 1 41 moves to the spring piece When the actuator 144 drives the rotating rod 141 to rotate in the opposite direction, the rotating rod 141 deflects toward the side of the spring sheet 143, so that the spring sheet 143 opens and the shell 23 is communicated with the outside. At this time, because the buckle 45 of the spring sheet 143 is not opened, the airflow entering the shell 23 passes through the speed reduction blocks 31 along the edge of the shell 1; when the actuator 144 drives the rotating rod 141 to rotate in the opposite direction, the rotating rod 141 deflects toward the side of the spring sheet 143, so that the spring sheet 143 opens and the shell 23 is communicated with the outside. At this time, because the buckle 45 of the spring sheet 142 is not opened, the airflow entering the shell 23 passes through the front side of the shell 1.
[0021] like Figure 6 As shown, the outlet assembly 5 includes a screw rod 51, a lifting plate 52 and a driver 53, wherein the screw rod 51 is rotatably arranged on the inner wall of the shell 2 3, the lifting plate 52 is passed through the screw rod 51 and threadedly matched therewith, the driver 2 53 is connected to one end of the screw rod 51, and the shell 2 3 is correspondingly provided with a window 2 and a slide groove 32 for the lifting plate 52 to slide.
[0022] In actual operation, the driver 2 53 drives the lifting plate 52 to move up and down by controlling the rotation of the screw 1 51. When the lifting plate 52 moves up to the slide groove 32, the window 2 is opened. When the lifting plate 52 moves down to the bottom, the window 2 is blocked and closed.
[0023] like Figure 5 As shown, an arc-shaped groove 33 is provided on the inner wall of the upper side of the shell 2 3 , and a plurality of through holes 34 penetrating vertically are provided on the upper side of the shell 2 3 at positions corresponding to the arc-shaped groove 33 .
[0024] The opening and closing assembly 6 includes a telescopic plate 61, a second screw rod 62, a group of transmission gears 63 and a third driver 64, wherein the telescopic plate 61 is slidably matched with the arc groove 33, the second screw rod 62 is penetrated in the telescopic plate 61 and threadedly matched therewith, the transmission gear 63 respectively connects the second screw rod 62 and the third driver 64, and the third driver 64 is fixed on the inner wall of the second shell 3.
[0025] Supplementary explanations based on the above structure are as follows: the number of through holes 34 only occupies half of the area of the arc groove 33. When the driver three 64 drives the screw two 62 to rotate through the transmission gear 63, the telescopic plate 61 is driven to slide in the arc groove 33. When the telescopic plate 61 moves to the position of the through hole 34, the through hole 34 is blocked, and the opening and closing component 6 is in a closed state. When the telescopic plate 61 leaves the position of the through hole 34, the through hole 34 is connected, and the opening and closing component 6 is in an open state. The above-mentioned driver one 44, driver two 53 and driver three 64 preferably use micro motors.
[0026] In one embodiment, Figure 4 , 8 As shown, an auxiliary component is arranged in the shell 23 relative to the front side of the shell 1, and the auxiliary component includes a rotating rod 2 71, a plurality of blades 72, a driving gear 73, a plurality of intermediate gears 74, a driven gear 75 and a rotating paddle 76, wherein the rotating rod 2 71 is rotatably arranged on the shell 23 and one end thereof passes through the lower side of the shell 23, the blades 72 are arranged on the rotating rod 2 71 at intervals, the driving gear 73 is sleeved on one end of the rotating rod 2 71 extending out of the shell 23, the intermediate gear 74 is rotatably arranged at the bottom of the shell 23 and cooperates with the driving gear 73, one end of the rotating paddle 76 is rotatably arranged on the shell 23, and the driven gear 75 is sleeved on the end of the rotating paddle 76 and cooperates with the intermediate gear 74.
[0027] The rotating paddle 76 is provided with a lubricating oil storage cylinder 8, which is fixed to the bottom of the housing 2 3 and is used to store lubricating oil and provide lubrication for the transmission shaft 2 through an external delivery system.
[0028] Furthermore, the rotating paddle 76 is a hollow structure and is connected from top to bottom. A number of branches 761 are arranged on the circumference of the rotating paddle 76. Each branch 761 is a hollow structure and is connected to the rotating paddle 76. The rotating paddle 76 and each branch 761 hollow structure form a heat dissipation channel 762. The shell 2 3 is provided with corresponding holes in cooperation with the upper opening of the rotating paddle 76, and the lubricating oil storage cylinder 8 is provided with corresponding holes in cooperation with the lower opening of the rotating paddle 76.
[0029] In actual operation, when air flows through the blades 72, the rotating rod 71 is driven to drive the rotating paddle 76 to rotate in the lubricating oil storage cylinder 8 through the transmission action of the driving gear 73, the intermediate gear 74 and the driven gear 75, thereby stirring the lubricating oil.
[0030] In one embodiment, Fig. 9As shown, the mid-mounted motor is installed on the electric bicycle, which includes a frame 91, a wheel 92, a crank 93, a pedal 94, a belt 95 and a driving pulley 96. The motor body is connected to the frame 91 and the inlet component 4 faces the front end of the frame 91. The wheels 92 are rotatably arranged on the front and rear sides of the frame 91 respectively. The crank 93 is connected to both ends of the transmission shaft 2. The pedal 94 is installed on the corresponding crank 93. The belt 95 connects the driving pulley 96 and the rear wheel 92. The driving pulley 96 is sleeved on one side of the transmission shaft 2.
[0031] Preferably, the frame 91 adopts a foldable structure.
[0032] In actual operation, human power steps on the pedal 94 to drive the transmission shaft 2 to rotate, and transmits power to the rear wheel 92 through the drive pulley 96 and the belt 95. At the same time, the central motor converts electrical energy into mechanical energy to assist the rotation of the transmission shaft 2 and reduce manpower.
[0033] Specifically, shell 2 3 can be used for multiple heat dissipation modes. The temperature sensor built into the electromagnetic module classifies the heat dissipation requirements according to the detected temperature combined with external factors: a warning temperature W is set. If the detected temperature is higher than the warning temperature W, the motor needs heat dissipation; if the detected temperature is lower than or equal to the warning temperature W, the motor does not need heat dissipation.
[0034] When the bicycle is in motion, the inlet component 4 is on the windward side, and the pressure sensor grades the wind force according to the detected wind pressure state, sets the warning wind pressure P, and classifies the wind pressure in the range of 0~P as suitable wind force, corresponding to the open state of the spring piece 2 43. In the suitable wind force state, the wind speed is moderate and will not cause excessive loss to the shell 1 and shell 2 3; the wind pressure greater than or equal to the P range is classified as warning wind force, corresponding to the open state of the spring piece 1 42. In the warning wind force state, the wind speed is relatively large and the loss to the surface of the shell 1 and shell 2 3 is relatively increased.
[0035] Based on the above classification, when the motor needs to dissipate heat, if it is in the warning wind state, the spring piece 42 opens to direct the wind to the deceleration block 31 for dispersion processing, thereby reducing its wind speed. At the same time, the opening and closing component 6 opens, and the wind entering the shell 2 3 leaves the opening and closing component 6, which can help the motor dissipate heat quickly with the help of the high-speed airflow during riding.
[0036] If the wind force is suitable, the spring piece 2 43 opens to guide the wind to the front space of the shell 1, fully contacting the front surface of the shell 1. At the same time, the outlet component 5 opens, and the wind entering the shell 2 3 leaves from the outlet component 5. Although the wind speed is slow, the contact area with the shell 2 3 is increased to improve the heat dissipation efficiency.
[0037] When the motor does not need to dissipate heat, the inlet assembly 4, the outlet assembly 5 and the opening and closing assembly 6 are all in a closed state, and the shell 2 3 can be used for internal heat preservation.
[0038] Furthermore, the heat dissipation channel 762 provided for the rotating paddle 76 can dissipate the heat of the lubricating oil synchronously through the circulation of airflow and rainwater.
[0039] Specifically, when the airflow flows through the blade 72, it drives the rotating paddle 76 to stir the lubricating oil. At the same time, the airflow passes through the upper opening of the rotating paddle 76, so that the upper opening is in a negative pressure state, so that the airflow at the lower end opening of the rotating paddle 76 flows into the heat dissipation channel 762, thereby taking away part of the heat of the lubricating oil through the air cooling effect, thereby achieving a heat dissipation effect.
[0040] If it is a rainy day, the inlet component 4 is closed, the outlet component 5 and the opening and closing component 6 are opened, and rainwater enters the shell 2 3 through the through hole 34 and leaves from the outlet component 5. At the same time, part of the rainwater will enter through the upper opening of the rotating paddle 76 and leave from the lower opening, thereby taking away part of the heat of the lubricating oil through the water cooling effect, achieving a heat dissipation effect.
[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0042] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A mid-mounted motor for an electric bicycle, comprising a motor body, characterized in that: The motor body is provided with a shell (1) on its outer cover, the shell (1) being used to assemble the motor body and provide basic protection for the motor body, the motor body comprising a transmission module and an electromagnetic module, wherein the transmission module is provided with a transmission shaft (2) rotatably arranged via a bearing, the two ends of the transmission shaft (2) extending out of the two side surfaces of the shell (1), the electromagnetic module being used for electromagnetic induction and being the main heating structure, the electromagnetic module being provided with a built-in temperature sensor for detecting the internal temperature state; The outer cover of the shell 1 (1) is provided with a shell 2 (3), the shell 2 (3) is a hollow structure and the space on one side of the inner side corresponds to the position of the electromagnetic module, the front and rear sides of the shell 2 (3) are respectively provided with an inlet component (4) and an outlet component (5), the upper side of the shell 2 (3) is provided with an opening and closing component (6), the inlet component (4) comprises a rotating rod 1 (41), a spring piece 1 (42), a spring piece 2 (43), a driver 1 (44) and a pressure sensor, wherein the rotating rod 1 (41) is rotatably arranged on the inner wall of one side of the shell 2 (3), one end of the spring piece 1 (42) and the one end of the spring piece 2 (43) are respectively connected to the rotating rod 1 (41), the driver 1 (44) is connected to the rotating rod 1 (41), and the pressure sensor is arranged on the rotating rod 1 (41) for detecting the wind pressure state blowing toward the surface of the rotating rod 1 (41); The second shell (3) is provided with a plurality of deceleration blocks (31) on the upper side relative to the electromagnetic module. The deceleration blocks (31) are of an S-shaped structure and are provided with a plurality of scattered holes (311).
2. The mid-mounted motor for an electric bicycle according to claim 1, characterized in that: The spring piece 1 (42) corresponds to the space where the shell 1 (1) is located, and the spring piece 2 (43) corresponds to the space on the other side of the shell 2 (3). The other ends of the spring piece 1 (42) and the spring piece 2 (43) are provided with buckles (45).
3. The mid-mounted motor for an electric bicycle according to claim 2, characterized in that: The outlet assembly (5) comprises a screw rod (51), a lifting plate (52) and a driver (53), wherein the screw rod (51) is rotatably arranged on the inner wall of the shell (3), the lifting plate (52) is inserted into the screw rod (51) and threadedly engaged with the screw rod, the driver (53) is connected to one end of the screw rod (51), and the shell (3) is provided with a window (2) and a slide groove (32) for the lifting plate (52) to slide.
4. The mid-mounted motor for an electric bicycle according to claim 3, characterized in that: An arc-shaped groove (33) is provided on the inner wall of the upper side of the shell body 2 (3), and a plurality of through holes (34) penetrating vertically are provided on the upper side of the shell body 2 (3) at positions corresponding to the arc-shaped groove (33).
5. The mid-mounted motor for an electric bicycle according to claim 4, characterized in that: The opening and closing assembly (6) comprises a telescopic plate (61), a second screw rod (62), a group of transmission gears (63) and a third driver (64), wherein the telescopic plate (61) is slidably matched with the arc-shaped groove (33), the second screw rod (62) is inserted into the telescopic plate (61) and threadedly matched therewith, the transmission gear (63) respectively connects the second screw rod (62) and the third driver (64), and the third driver (64) is fixed on the inner wall of the second shell (3).
6. The mid-mounted motor for an electric bicycle according to claim 5, characterized in that: The number of the through holes (34) occupies half the area of the arc-shaped groove (33).
7. The mid-mounted motor for an electric bicycle according to claim 6, characterized in that: An auxiliary component is arranged in the second housing (3) at the front side relative to the first housing (1), and the auxiliary component comprises a second rotating rod (71), a plurality of blades (72), a driving gear (73), a plurality of intermediate gears (74), a driven gear (75) and a rotating paddle (76), wherein the second rotating rod (71) is rotatably arranged on the second housing (3) and one end thereof passes through the lower side of the second housing (3), the blades (72) are arranged at intervals on the second rotating rod (71), the driving gear (73) is sleeved on one end of the second rotating rod (71) extending out of the second housing (3), the intermediate gear (74) is rotatably arranged at the bottom of the second housing (3) and cooperates with the driving gear (73), one end of the rotating paddle (76) is rotatably arranged on the second housing (3), and the driven gear (75) is sleeved on the end of the rotating paddle (76) and cooperates with the intermediate gear (74).
8. The mid-mounted motor for an electric bicycle according to claim 7, characterized in that: The outer cover of the rotating paddle (76) is provided with a lubricating oil storage cylinder (8), and the lubricating oil storage cylinder (8) is fixed to the bottom of the second shell (3).
9. The mid-mounted motor for an electric bicycle according to claim 8, characterized in that: The rotating paddle (76) is a hollow structure and is connected from top to bottom. The rotating paddle (76) is provided with a plurality of branches (761) on its circumference. Each of the branches (761) is a hollow structure and is connected to the rotating paddle (76). The rotating paddle (76) and the hollow structures of each of the branches (761) form a heat dissipation channel (762). The second shell (3) is provided with a corresponding hole in cooperation with the upper opening of the rotating paddle (76). The lubricating oil storage cylinder (8) is provided with a corresponding hole in cooperation with the lower opening of the rotating paddle (76).
10. An electric bicycle using the electric bicycle mid-mounted motor according to claim 9, characterized in that: The vehicle comprises a frame (91), a wheel (92), a crank (93), a pedal (94), a belt (95), and a driving pulley (96); the motor body is connected to the frame (91), and the inlet assembly (4) faces the front end of the frame (91); the wheel (92) is rotatably arranged on the front and rear sides of the frame (91), the crank (93) is connected to both ends of the transmission shaft (2), the pedal (94) is mounted on the corresponding crank (93), the belt (95) connects the driving pulley (96) and the rear wheel (92), and the driving pulley (96) is sleeved on one side of the transmission shaft (2).