An electric powertrain

Abstract

The present invention relates to the field of electric power assistance of electric bicycles, and in particular to an electric power assistance power assembly, including a drive assembly, a drive mechanism is arranged in the middle of the drive assembly, the drive mechanism drives the left pedal shaft, and a speed reduction mechanism is also installed on the left pedal shaft, the left pedal shaft is transmitted to the right pedal shaft through a torsion bar, and a sensing mechanism is arranged at the position of the torsion bar. The functions of a torque sensor, a motor position sensor, and a vehicle speed sensor are realized by a sensor, thereby reducing the number of sensors, and in addition, the pedal shaft torque, the motor angle position, and the wheel speed are detected at the same time, and accurate torque requirements are obtained by combining them, and the torque requirements are provided to a control element to control the motor output to adapt to the current riding assistance; the present invention realizes the deep integration of the power assistance drive mechanism, the speed reduction mechanism, the sensing mechanism, and the motor controller in a small, lightweight, and efficient power assembly through a clever structural design, so as to improve its adaptability to electric power assistance bicycles, and the overall cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of electric power assistance of electric bicycles, and in particular to an electric power assistance power assembly. Background Art

[0002] The power output of electric assisted bicycles is generally of the following two types: 1. The reducer part adopts a parallel axis structure, the sensor part adopts the stress sheet principle, the motor part has a switch Hall sensor, and the controller and the drive motor are split. That is, on the whole vehicle, usually a speed sensor and a torque sensor are set separately, there is no position sensor, and the functions of multiple sensors are scattered and cannot be integrated.

[0003] 2: External rotor motor, the reducer adopts a planetary gear structure, the output shaft of the power assist motor and the pedal shaft are arranged in series, and a torque sensor of conventional structure is adopted; the motor does not have a position sensor. The controller and the drive motor are split.

[0004] Both of the above solutions have the problem of large size and weight of the power assist system and high cost of the torque sensor, because there is usually no position sensor in the motor, which leads to low efficiency and energy efficiency of the power assist system. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an electric powertrain.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electric powertrain assembly includes a drive assembly, wherein a left pedal shaft and a right pedal shaft are installed on both sides of the drive assembly, a sprocket wheel and a left pedal are installed on the left pedal shaft, and a right pedal is installed on the right pedal shaft;

[0008] A driving mechanism is arranged in the middle of the driving assembly, and the driving mechanism drives the left pedal shaft, and a speed reduction mechanism is also installed on the left pedal shaft. The left pedal shaft is connected to the right pedal shaft through a torsion bar, and a sensing mechanism is arranged at the position of the torsion bar.

[0009] Preferably, the driving mechanism includes a motor rotor, which is drivingly connected to a motor rotor shaft, the motor rotor shaft is decelerated by a deceleration mechanism, and the deceleration mechanism transmits the left pedal shaft through a connector.

[0010] Preferably, the sensing mechanism includes a PCB board, three groups of coils are arranged on both sides of the PCB board, and eddy current sensors are respectively formed between the first sensor rotor and the second sensor rotor on both sides of the PCB board. A motor controller is arranged on the PCB board, and the motor controller and the constructed eddy current sensor share the PCB board.

[0011] Preferably, the motor rotor is driven by a motor, and the motor further includes a motor housing and a motor stator adapted to the motor rotor.

[0012] Preferably, the reduction mechanism includes a planetary carrier, multiple planetary gears, a sun gear and a ring gear. The sun gear is mounted on the motor rotor shaft. The sun gear meshes with and drives multiple planetary gears. Each planetary gear is mounted on the planetary carrier. The planetary carrier drives a connector, and the connector is mounted on the left pedal shaft.

[0013] Preferably, the sun gear is located in the middle of the plurality of planetary gears and meshes with each of the planetary gears.

[0014] Preferably, the first rotor of the sensor and the left coil on the PCB board constitute an eddy current sensor for detecting the position of the motor rotor shaft.

[0015] Preferably, the second rotor of the sensor is connected to the left pedal shaft through a torsion bar, and the second rotor of the sensor and the right coil on the PCB board constitute an eddy current sensor for speed and torque detection of the rear wheel.

[0016] Preferably, the first rotor of the sensor is connected to the motor rotor shaft, and the second rotor of the sensor is connected to the right pedal shaft.

[0017] Preferably, the electric-assisted bicycle is equipped with a driving assembly and a sprocket, and the sprocket drives the rear wheel through a chain, and a display connected to the electrical signal of the sensor mechanism is installed on the handlebar.

[0018] The beneficial effects of the present invention are:

[0019] 1. In the present invention, the functions of torque sensor, motor position sensor and vehicle speed sensor are realized by one sensor, thereby reducing the number of sensors. In addition, the pedal shaft torque, motor angle position and wheel speed are detected simultaneously, and accurate torque requirements are obtained by combining them, which are provided to the control element to control the motor output to adapt to the current riding assistance.

[0020] 2. In the present invention, the entire solution can be adjusted bilaterally symmetrically to meet the actual arrangement position of the chain plate for different vehicle models.

[0021] 3. The present invention realizes deep integration of the power-assisted driving mechanism, the speed reduction mechanism, the sensor mechanism and the motor controller into a compact, lightweight and efficient powertrain through ingenious structural design, so as to improve its adaptability to electric-assisted bicycles, and the overall cost is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an electric powertrain proposed by the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the drive assembly proposed by the present invention;

[0024] Figure 3 It is a structural schematic diagram of the driving mechanism proposed by the present invention;

[0025] Figure 4 An exploded diagram of the driving mechanism proposed by the present invention;

[0026] Figure 5 It is a structural schematic diagram of the sensing mechanism proposed by the present invention;

[0027] Figure 6 An exploded diagram of the sensor mechanism proposed by the present invention;

[0028] Figure 7 It is a structural schematic diagram of the speed reduction mechanism proposed by the present invention;

[0029] Figure 8 An exploded diagram of the speed reduction mechanism proposed by the present invention;

[0030] Fig. 9 This is a structural diagram of the electric power-assisted bicycle proposed by the present invention.

[0031] In the figure: 1 driving assembly, 2 sprocket, 3 left pedal, 4 right pedal, 5 left pedal shaft, 6 right pedal shaft, 7 driving mechanism, 8 reduction mechanism, 9 sensing mechanism, 71 motor rotor, 72 motor rotor shaft, 73 connector, 74 torsion bar, 81 ring gear, 82 planet carrier, 83 planetary gear, 84 sun gear, 91 sensor first rotor, 92 PCB board, 93 sensor second rotor, 10 display, 11 rear wheel. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] Reference Figure 1-9 , an electric powertrain, comprising a drive assembly 1, a left pedal shaft 5 and a right pedal shaft 6 are installed on both sides of the drive assembly 1, a sprocket 2 and a left pedal 3 are installed on the left pedal shaft 5, and a left pedal 4 is installed on the right pedal shaft 6;

[0034] A driving mechanism 7 is provided in the middle of the driving assembly 1, and the driving mechanism 7 drives the left pedal shaft 5, and a reduction mechanism 8 is also installed on the left pedal shaft 5. The left pedal shaft 5 is connected to the right pedal shaft 6 through a torsion bar 74, and a sensor mechanism 9 is provided at the position of the torsion bar 74.

[0035] The driving mechanism 7 includes a motor rotor 71, the motor rotor 71 is drivingly connected to a motor rotor shaft 72, the motor rotor shaft 72 is decelerated by a deceleration mechanism 8, and the deceleration mechanism 8 transmits the left pedal shaft 5 through a connector 73. The motor rotor 71 is driven by a motor, and the motor also includes a motor housing and a motor stator adapted to the motor rotor 71.

[0036] The speed reduction mechanism 8 includes a planet carrier 82, a plurality of planetary gears 83, a sun gear 84 and a ring gear 81. The sun gear 84 is mounted on the motor rotor shaft 72. The sun gear 84 meshes with and drives the plurality of planetary gears 83. Each planetary gear 83 drives the planet carrier 82 to rotate. The planet carrier 82 drives the connector 73. The connector 73 is mounted on the left pedal shaft 5. Moreover, the sun gear 84 is located in the middle of the plurality of planetary gears 83 and meshes with each planetary gear 83.

[0037] Among them, protrusions are provided at both ends of the torsion rod 74, and the two ends of the torsion rod 74 are respectively installed with interference fit with the connecting notches on the left pedal shaft 5 and the right pedal shaft 6.

[0038] The sensing mechanism 9 includes a PCB board 92 , three groups of coils are arranged on both sides of the PCB board 92 , and a motor controller is arranged on the PCB board 92 , and the motor controller and the constructed eddy current sensor share the PCB board 92 .

[0039] The first rotor 91 of the sensor and the left coil on the PCB board 92 constitute an eddy current sensor for detecting the position of the motor rotor shaft 72; the second rotor 93 of the sensor is connected to the left pedal shaft 5 through the torsion bar 74, and the second rotor 93 of the sensor and the right coil on the PCB board 92 constitute an eddy current sensor for detecting the speed and torque of the rear wheel.

[0040] Moreover, the electric power-assisted bicycle is equipped with a driving assembly 1 and a sprocket 2, and the sprocket 2 drives the rear wheel 11 through a chain, and a display 10 connected to the sensor mechanism 9 by electrical signals is installed on the handlebar.

[0041] In this embodiment, the driving assembly 1 drives the left pedal shaft 5 through the driving mechanism 7, and the left pedal shaft 5 is decelerated through the deceleration mechanism 8, so that the left pedal shaft 5 drives the sprocket 2 to output power.

[0042] Among them, the driving mechanism 7 drives the motor rotor shaft 72 through the motor and the motor rotor 71, and the sun gear 84 is transmitted on the motor rotor shaft 72, and the sun gear 84 is meshed with and transmitted by multiple planetary gears 83. Through the speed ratio of the number of teeth, position and diameter change of the two, the speed is reduced and the torque is increased. The planetary gear 83 outputs the torque after the speed is reduced to the planetary carrier 82, and the planetary carrier 82 then drives the connector 73 and the left pedal shaft 5 to realize the transmission and deceleration of the left pedal shaft 5.

[0043] At the same time, the torsion bar 74 is used to connect the left pedal shaft 5 and the right pedal shaft 6, and three groups of coils are arranged on both sides of the PCB board 92 on the torsion bar 74, and eddy current sensors are respectively formed between the sensor first rotor 91 and the sensor second rotor 93 on both sides of the PCB board 92. Moreover, the sensor first rotor 91 is connected to the motor rotor shaft 72, and the sensor second rotor 93 is connected to the right pedal shaft 6, so that the position, speed and torque of the motor rotor shaft 72 and the motor rotor 71 can be accurately detected, and signals can be provided to the motor controller to facilitate the control of the motor.

[0044] Among them, the real-time speed of the bicycle can be calculated through the rotation speed of the right pedal shaft, the speed ratio of the sprocket, and the diameter of the wheel, and displayed on the monitor.

[0045] In the present invention, the functions of a torque sensor, a motor position sensor, and a vehicle speed sensor are realized by one sensor, thereby reducing the number of sensors. In addition, the pedal shaft torque, the motor angle position, and the wheel speed are detected simultaneously, and accurate torque requirements are obtained by combining them to provide the control element with control motor output to adapt to the current riding assistance.

[0046] Moreover, the entire solution can be adjusted symmetrically to meet the actual layout of the chain plate for different models.

[0047] The present invention achieves deep integration of the power-assisted driving mechanism, the speed reduction mechanism, the sensor mechanism and the motor controller into a compact, lightweight and highly efficient power assembly through ingenious structural design, so as to improve its adaptability to electric power-assisted bicycles.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electric powertrain, comprising a drive assembly (1), characterized in that: The drive assembly (1) is provided with a left pedal shaft (5) and a right pedal shaft (6) on both sides of the drive assembly (1), and a sprocket wheel (2) and a left pedal (3) are installed on the left pedal shaft (5), and a right pedal (4) is installed on the right pedal shaft (6); A driving mechanism (7) is provided in the middle of the driving assembly (1), the driving mechanism (7) drives the left pedal shaft (5), and a speed reduction mechanism (8) is also installed on the left pedal shaft (5), the left pedal shaft (5) is connected to the right pedal shaft (6) via a torsion bar (74), and a sensing mechanism (9) is provided at the position of the torsion bar (74); the driving mechanism (7) comprises a motor rotor (71), the motor rotor (71) is drivingly connected to a motor rotor shaft (72), the motor rotor shaft (72) is decelerated by the speed reduction mechanism (8), and the speed reduction mechanism (8) drives the left pedal shaft (5) via a connector (73); The sensing mechanism (9) comprises a PCB board (92), three groups of coils are arranged on both sides of the PCB board (92), and eddy current sensors are respectively formed between the first sensor rotor (91) and the second sensor rotor (93) on both sides of the PCB board (92), and a motor controller is arranged on the PCB board (92), and the motor controller and the formed eddy current sensor share the PCB board (92); The sensor first rotor (91) and the left coil on the PCB board (92) form an eddy current sensor for detecting the position of the motor rotor shaft (72); The second rotor (93) of the sensor is connected to the left pedal shaft (5) via a torsion bar (74); the second rotor (93) of the sensor and the right coil on the PCB board (92) form an eddy current sensor for detecting the speed and torque of the rear wheel.

2. The electric powertrain according to claim 1, characterized in that: The motor rotor (71) is driven by a motor, and the motor further comprises a motor housing and a motor stator adapted to the motor rotor (71).

3. The electric powertrain according to claim 1, characterized in that: The speed reduction mechanism (8) comprises a planet carrier (82), a plurality of planetary gears (83), a sun gear (84) and a ring gear (81); the sun gear (84) is mounted on the motor rotor shaft (72); the sun gear (84) meshes with and drives the plurality of planetary gears (83); each planetary gear (83) is mounted on the planet carrier (82); the planet carrier (82) drives a connector (73); and the connector (73) is mounted on the left pedal shaft (5).

4. The electric powertrain according to claim 3, characterized in that: The sun gear (84) is located in the middle of the plurality of planetary gears (83) and meshes with each of the planetary gears (83).

5. The electric powertrain according to claim 1, characterized in that: Both ends of the torsion bar (74) are provided with protrusions, and the two ends of the torsion bar (74) are respectively installed with interference fit with the connecting notches on the left pedal shaft (5) and the right pedal shaft (6).

6. An electric-assisted bicycle equipped with the electric-assisted powertrain according to claim 1, characterized in that: The electric power-assisted bicycle is equipped with a drive assembly (1) and a sprocket wheel (2), wherein the sprocket wheel (2) drives a rear wheel (11) via a chain, and a display (10) connected to an electrical signal of a sensor mechanism (9) is installed on the handlebar.

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