Electric vehicle

Abstract

The utility model relates to the technical field of electric vehicles, in particular to an electric vehicle which comprises a motor, a battery component, a frame, a rear fork, a rear fork shaft, a motor power output chain wheel and a rear wheel power input chain wheel, a rear wheel is arranged on the rear section of the rear fork, and the rear wheel power input chain wheel is connected to a hub of the rear wheel. Power is transmitted between the motor power output chain wheel and the rear wheel power input chain wheel through a chain or a belt, the motor comprises an inner stator and an outer rotor, an axial inner stator through hole is formed in the center of the inner stator, the motor power output chain wheel is axially fixed to the side face of the outer rotor, and the rear bottom fork shaft is assembled in the inner stator through hole in a matched mode. The central axis of the power output chain wheel of the motor, the central axis of the inner stator and the central axis of the rear fork shaft are located on the same straight line, and by the adoption of the technical scheme, it is guaranteed that a preset distance is kept no matter how the rear fork rotates, and therefore it is guaranteed that the tension degree of a transmission chain or a transmission belt is kept consistent.

Description

Technical Field

[0001] This utility model relates to the field of electric vehicle technology. Background Technology

[0002] Existing mid-drive electric bicycles include a frame, electric motor, battery, rear swingarm, rear wheel, electric motor power output sprocket, and rear wheel power input sprocket. The rear wheel is located at the rear of the rear swingarm, and the rear wheel power input sprocket is connected to the rear wheel hub. The electric motor is primarily a mid-drive motor, employing an outer stator and inner rotor structure. The inner rotor is the motor shaft. The electric motor power output sprocket on the motor shaft directly drives the rear wheel power input sprocket on the rear wheel hub, which is supported and fixed at the rear of the rear swingarm, via a transmission chain or belt. A rear swingarm axle is located between the power take-off sprocket and the rear wheel power input sprocket. The rear swingarm is rotatably connected to the middle section of the frame via this axle. This structure is simple and practical, and is the existing arrangement for a mid-mounted electric motor in electric vehicles. However, because the motor shaft and the rear swingarm axle are not collinear, the distance between the rear wheel power input sprocket and the motor power output sprocket changes when the rear swingarm swings. This causes changes in the tension of the drive chain or belt, leading to interference between the drive chain or belt and the rear swingarm, and potentially even breakage or loosening and detachment of the chain or belt. This situation frequently occurs, especially when off-road vehicles are performing extreme maneuvers, particularly when the rear swingarm swings significantly. Utility Model Content

[0003] This utility model addresses the shortcomings of existing technologies by proposing an electric vehicle that solves the problem of the motor shaft and the rear swingarm shaft being off-axis, thus ensuring that the tension of the transmission chain or belt remains stable regardless of how the rear swingarm rotates. Furthermore, it integrates the frame, rear swingarm, and motor together via the rear swingarm shaft, reducing assembly difficulty and increasing strength.

[0004] To achieve the above objectives, this patent application discloses an electric vehicle, comprising an electric motor, a battery pack, a frame, a rear swingarm, a rear swingarm axle, a rear shock absorber, a rear wheel, an electric motor power output sprocket, and a rear wheel power input sprocket. The rear wheel is located at the rear section of the rear swingarm, and the rear wheel power input sprocket is connected to the hub of the rear wheel. Power is transmitted between the electric motor power output sprocket and the rear wheel power input sprocket via a chain or belt. The electric motor includes an inner stator and an outer rotor. The inner stator has an axial through hole at its center. The electric motor power output sprocket is axially fixed to the side of the outer rotor. The rear swingarm axle is fitted into the through hole of the inner stator. The central axis of the electric motor power output sprocket, the central axis of the inner stator, and the central axis of the rear swingarm axle are on the same straight line.

[0005] By adopting the above technical solution, the motor uses an inner stator and an outer rotor, and the inner stator has an axial through hole at its center, which differs from the structure of a typical mid-mounted motor with an outer stator and an inner rotor. The rear swingarm shaft of this patent passes through the front section of the rear swingarm and the inner stator through hole, supporting the motor and the front section of the rear swingarm on the frame. This ensures that the distance between the rear swingarm shaft and the rear wheel power input sprocket remains predetermined regardless of how the rear swingarm rotates, thus ensuring consistent tension of the drive chain or belt. Furthermore, compared to a virtual coaxial design, it reduces assembly difficulty and increases strength.

[0006] Further specified, the motor power output sprocket is provided with a motor power output sprocket connection hole; the outer rotor side is provided with an outer rotor threaded hole that matches the motor power output sprocket connection hole; the motor power output sprocket is fixed to the outer rotor side by bolts.

[0007] By adopting the above technical solution, it is very convenient to fix the motor power output sprocket to the outer rotor, while also reducing the axial movement of the motor power output sprocket.

[0008] Further defined, the frame includes a left main frame and a right main frame extending vertically, the middle section of the left main frame is provided with a left frame bottom bracket hole, and the middle section of the right main frame is provided with a right frame bottom bracket hole; the rear swingarm includes a left rear swingarm and a right rear swingarm extending longitudinally, the front end of the left rear swingarm is provided with a left rear swingarm shaft hole, and the front end of the right rear swingarm is provided with a right rear swingarm shaft hole; the rear swingarm shaft passes sequentially through the left frame bottom bracket hole, the left rear swingarm shaft hole, the inner stator through hole, the right rear swingarm shaft hole, and the right frame bottom bracket hole.

[0009] In addition, in order to better reduce the connection distance between the battery pack and the motor and ensure the stability of the connection with the shortest distance, the rear end of the battery pack is connected to the front end of the motor, and the upper end of the battery pack is connected to the vehicle frame. This power arrangement is also beneficial to the stability of the vehicle's center of gravity.

[0010] To ensure the stability of the frame, this technical solution also includes a lower connecting rod. The lower end of the left main frame is provided with a left frame lower axle hole, and the lower end of the right main frame is provided with a right frame lower axle hole. The left main frame is connected to the left end of the lower connecting rod by bolts passing through the left frame lower axle hole; the right main frame is connected to the right end of the lower connecting rod by bolts passing through the right frame lower axle hole.

[0011] Similarly, this technical solution also includes a left subframe and a right subframe, wherein the left subframe is connected to the upper end of the left main frame and the right subframe is connected to the upper end of the right main frame; both the left and right subframes are triangular supports, and at least two corner points of the triangular supports are fixedly connected to the frame.

[0012] To better ensure the stability of the left and right rear swingarms and to better connect the rear shock absorber to the rear swingarms, the system further includes a lower support rod for the rear shock absorber, which connects the front sections of the left and right rear swingarms. The lower support rod has a lower support seat for the rear shock absorber at the middle of its upper end, and the lower end of the rear shock absorber is hinged to the lower support seat.

[0013] Furthermore, this technical solution also includes a left main frame bearing and a right main frame bearing. The left main frame bearing is disposed within the left frame center shaft hole, and the right main frame bearing is disposed within the right frame center shaft hole. To facilitate movement between the rear swingarm shaft and the rear swingarm, bushings are typically only installed at corresponding points on the frame. However, after prolonged use and under stress, these bushings easily wear down, creating gaps and causing the rear swingarm to wobble. The left and right main frame bearings in this technical solution better ensure the stability of movement between the rear swingarm shaft and the rear swingarm, ensuring axial runout of the rear swingarm. This is particularly suitable for high-impact vehicles such as off-road motorcycles where the rear swingarm rotates significantly. In this configuration, the rear swingarm shaft passes sequentially through the left main frame bearing, the left rear swingarm shaft hole, the inner stator through hole, the right rear swingarm shaft hole, and the right main frame bearing, allowing for more flexible rear swingarm rotation and effectively preventing radial runout of the rear swingarm, thus ensuring the overall stability of the vehicle's performance.

[0014] Compared with the prior art, this utility model has the following advantages:

[0015] Since the central axis of the motor power output sprocket, the central axis of the inner stator, and the central axis of the rear swingarm shaft are on the same straight line, the distance between the rear swingarm shaft and the rear wheel power input sprocket on the rear wheel hub will not change no matter how the rear swingarm swings. In other words, the tension of the chain or belt will not change, and the transmission chain or belt will not interfere with the rear swingarm. This extends the service life of the transmission chain and belt. At the same time, there is no need to reduce the tension in advance to adapt to changes in tension, which would cause additional noise and transmission vibration.

[0016] This invention has a simple structure and low component cost. It has wide applicability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structural assembly of this utility model. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. Example

[0019] like Figure 1 As shown, an electric vehicle includes a motor 1, a battery pack 2, a frame, a rear swingarm, a rear swingarm axle 5, a rear shock absorber 6, a rear wheel, a motor power output sprocket 7, and a rear wheel power input sprocket 8. The frame includes a left main frame 31 and a right main frame 32 extending vertically. The left main frame 31 has a left frame axle hole 310 in its middle section, and the right main frame 32 has a right frame axle hole 320 in its middle section. The rear swingarm includes a left rear swingarm 41 and a right rear swingarm 42 extending horizontally. The left rear swingarm 41 has a left rear swingarm axle hole 411 at its front end, and the right rear swingarm 42 has a right rear swingarm axle hole 421 at its front end. The rear wheel (not shown in the figure) The rear swingarm shaft 5 is located at the rear end of the rear swingarm. The rear wheel power input sprocket 8 is connected to the hub of the rear wheel. The motor power output sprocket 7 and the rear wheel power input sprocket 8 transmit power through a chain or belt. The motor 1 includes an inner stator 11 and an outer rotor 12. The inner stator 11 has an axial inner stator through hole 111 at its center. The motor power output sprocket 7 is axially fixed to the side of the outer rotor 12. The rear swingarm shaft 5 is fitted into the inner stator through hole 111. The central axis of the motor power output sprocket 7, the central axis of the inner stator 11, and the central axis of the rear swingarm shaft are on the same straight line. The rear swingarm shaft 5 passes sequentially through the left frame axle hole 310, the left rear swingarm shaft hole 411, the inner stator through hole 121, the right rear swingarm shaft hole 421, and the right frame axle hole 320.

[0020] By adopting the above technical solution, the motor uses an inner stator and an outer rotor, and the inner stator has an axial through hole at its center, which differs from the structure of a typical mid-mounted motor with an outer stator and an inner rotor. The rear swingarm shaft of this patent passes through the front section of the rear swingarm and the inner stator through hole, supporting the motor and the front section of the rear swingarm on the frame. This ensures that the distance between the rear swingarm shaft and the rear wheel power input sprocket remains predetermined regardless of how the rear swingarm rotates, thus ensuring consistent tension of the drive chain or belt. Furthermore, compared to a virtual coaxial design, it reduces assembly difficulty and increases strength.

[0021] In addition, since the mid-mounted motor has an external rotor and an internal stator structure, the internal stator of the motor needs to be supported so that there is a mechanism to provide reaction force when power output is needed. In this way, when we output power, the reaction force of the motor will press down the front end of the rear horizontal fork, which will increase the explosive force of the whole vehicle when starting, just like when we push down with our legs when running.

[0022] In addition, because the inner rotor of the existing mid-mounted motor has a small rotor diameter, all mid-mounted inner rotor motors are equipped with a gearbox to increase the output torque, so that they can start and climb better. The outer rotor of the present technology has a larger force-bearing rotation radius, so the rear wheel can be directly driven by the motor power output sprocket. This results in better spatial layout and energy consumption of the transmission system.

[0023] Further optimization includes: the motor power output sprocket 7 is provided with a motor power output sprocket connection hole 71; the outer rotor 12 is provided with an outer rotor threaded hole 121 that matches the motor power output sprocket connection hole 71; the motor power output sprocket 7 is fixed on the side of the outer rotor 12 by bolts 9.

[0024] By adopting the above technical solution, the motor power output sprocket 7 can be conveniently fixedly connected to the outer rotor 12, while also reducing the axial movement of the motor power output sprocket, thereby ensuring the axial runout of the chain or belt and more stably protecting the stability of power transmission.

[0025] In addition, in order to better reduce the connection distance between the battery pack and the motor and ensure the stability of the electrical connection with the shortest distance, the rear end of the battery pack 2 is connected to the front end of the motor 1, and the upper end of the battery pack 2 is connected to the vehicle frame. This power arrangement is also beneficial to the stability of the vehicle's center of gravity.

[0026] To ensure the stability of the frame, this technical solution also includes a lower connecting rod 30. The lower end of the left main frame has a left frame lower axle hole 313, and the lower end of the right main frame has a right frame lower axle hole 323. The left main frame is connected to the left end of the lower connecting rod 30 by bolts 9 passing through the left frame lower axle hole 313; the right main frame is connected to the right end of the lower connecting rod 30 by bolts 9 passing through the right frame lower axle hole 323. Alternatively, the front pedals 92 can be positioned outside the left and right frame lower axle holes 313 and 323, respectively. Bolts 9 can be used to connect the right front pedal 92 and the right frame to the right end of the lower connecting rod 30, and similarly, bolts 9 can be used to connect the left front pedal 92 and the left frame to the left end of the lower connecting rod 30.

[0027] Similarly, this technical solution also includes a left subframe 310 and a right subframe 320. The left subframe 310 is connected to the upper end of the left main frame 31, and the right subframe 320 is connected to the upper end of the right main frame 32. Both the left subframe 310 and the right subframe 320 are triangular supports, and at least two corner points of the triangular supports are fixedly connected to the frame.

[0028] To better ensure the stability of the left rear swingarm 41 and the right rear swingarm 42, and to better connect the rear shock absorber to the rear swingarm, a rear shock absorber lower support rod 40 is further included. The rear shock absorber lower support rod 40 connects the front sections of the left rear swingarm 41 and the right rear swingarm 42. A rear shock absorber lower support seat 401 is provided at the middle of the upper end of the rear shock absorber lower support rod 40, and the lower end of the rear shock absorber 6 is hinged to the rear shock absorber lower support seat 401.

[0029] In this technical solution, the left and right main frame bearings are positioned inside the main frames on both sides. Therefore, the rear swingarm shaft locks the inner holes of the bearings on both sides of the frame, the rear swingarm body, and the inner fixed stator of the external rotor motor together. In this way, the inner stator of the motor and the rear swingarm body are locked together and rotated by the bearings on both sides of the frame.

[0030] Compared with the prior art, this utility model has the following advantages:

[0031] Since the central axis of the motor power output sprocket, the central axis of the inner stator, and the central axis of the rear swingarm shaft are on the same straight line, the distance between the rear swingarm shaft and the rear wheel power input sprocket on the rear wheel hub will not change no matter how the rear swingarm swings. In other words, the tension of the chain or belt will not change, and the transmission chain or belt will not interfere with the rear swingarm. This extends the service life of the transmission chain and belt. At the same time, there is no need to reduce the tension in advance to adapt to changes in tension, which would cause additional noise and transmission vibration.

[0032] This patent uses a motor that differs from commonly used motors. The motor used in this patent is an external rotor, internal stator motor. The working principle of this motor mechanism is the same as that of a hub motor, in which the stator shaft is fixed and the external rotor rotates like a rear wheel.

[0033] In addition, this structure, which directly uses the rear horizontal fork shaft as the stator center shaft (center iron core), is also conducive to increasing the magnetic flux. Using this type of motor mechanism can output power more effectively.

[0034] In addition, this technical solution also includes a left main frame bearing 311 and a right main frame bearing 321. The left main frame bearing 311 is disposed in the left frame central shaft hole 310, and the right main frame bearing 321 is disposed in the right frame central shaft hole 320. To facilitate movement between the rear swingarm shaft 5 and the rear swingarm, existing electric vehicles typically only have bushings installed at the corresponding points on the frame. This can easily lead to wear and gaps after prolonged use and stress, causing the rear swingarm to wobble. The left main frame bearing 311 and right main frame bearing 321 of this technical solution better ensure the stability of movement between the rear swingarm shaft 5 and the rear swingarm, ensuring axial runout of the rear swingarm. This is particularly suitable for situations involving large reciprocating rotation of the rear swingarm during high-impact movements, such as in off-road vehicles. In this configuration, the rear swingarm shaft 5 passes sequentially through the left main frame bearing 311, the left rear swingarm shaft hole 411, the inner stator through hole 111, the right rear swingarm shaft hole 421, and the right main frame bearing 321, making the rear swingarm rotation more flexible and effectively preventing radial runout of the rear swingarm as a whole, thereby ensuring the stability of the overall vehicle performance.

[0035] This invention has a simple structure and low component cost. It has wide applicability.

[0036] The description of the specific embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that the above description is only a preferred embodiment of this utility model. For those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications will also fall within the protection scope of the claims of this utility model.

Claims

1. An electric vehicle, comprising an electric motor, a battery pack, a frame, a rear swingarm, a rear swingarm axle, a rear shock absorber, a rear wheel, an electric motor power output sprocket, and a rear wheel power input sprocket, wherein the rear wheel is disposed at the rear section of the rear swingarm, the rear wheel power input sprocket is connected to the hub of the rear wheel, and power is transmitted between the electric motor power output sprocket and the rear wheel power input sprocket via a chain or belt, characterized in that: The electric motor includes an inner stator and an outer rotor. The inner stator has an axial through hole at its center. The power output sprocket of the electric motor is axially fixed to the side of the outer rotor. The rear flat fork shaft is fitted into the through hole of the inner stator. The central axis of the power output sprocket of the electric motor, the central axis of the inner stator, and the central axis of the rear flat fork shaft are on the same straight line.

2. An electric vehicle according to claim 1, characterized in that: The motor power output sprocket is provided with a motor power output sprocket connection hole; the outer rotor side is provided with an outer rotor threaded hole that matches the motor power output sprocket connection hole; the motor power output sprocket is fixed to the outer rotor side by bolts.

3. An electric vehicle according to claim 1, characterized in that: The frame includes a left main frame and a right main frame extending vertically. The middle section of the left main frame has a left frame bottom bracket hole, and the middle section of the right main frame has a right frame bottom bracket hole. The rear swingarm includes a left rear swingarm and a right rear swingarm extending longitudinally. The front end of the left rear swingarm has a left rear swingarm shaft hole, and the front end of the right rear swingarm has a right rear swingarm shaft hole. The rear swingarm shaft passes sequentially through the left frame bottom bracket hole, the left rear swingarm shaft hole, the inner stator through hole, the right rear swingarm shaft hole, and the right frame bottom bracket hole.

4. An electric vehicle according to claim 1, characterized in that: The rear end of the battery assembly is connected to the front end of the electric motor, and the upper end of the battery assembly is connected to the vehicle frame.

5. An electric vehicle according to claim 3, characterized in that: It also includes a lower connecting rod, with a left frame lower axle hole at the lower end of the left main frame and a right frame lower axle hole at the lower end of the right main frame; the left main frame is connected to the left end of the lower connecting rod by bolts passing through the left frame lower axle hole; the right main frame is connected to the right end of the lower connecting rod by bolts passing through the right frame lower axle hole.

6. An electric vehicle according to claim 3, characterized in that: It also includes a left subframe and a right subframe, the left subframe being connected to the upper end of the left main frame and the right subframe being connected to the upper end of the right main frame.

7. An electric vehicle according to claim 6, characterized in that: Both the left and right subframes are triangular supports, and at least two corner points of each triangular support are fixedly connected to the frame.

8. An electric vehicle according to claim 3, characterized in that: It also includes a rear shock absorber lower support rod, which connects the front sections of the left and right rear horizontal forks; a rear shock absorber lower support seat is provided at the middle of the upper end of the rear shock absorber lower support rod, and the lower end of the rear shock absorber is hinged to the rear shock absorber lower support seat.

9. An electric vehicle according to claim 3, characterized in that: It also includes a left main frame bearing and a right main frame bearing, wherein the left main frame bearing is disposed in the left frame center shaft hole and the right main frame bearing is disposed in the right frame center shaft hole.

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