Wheel hub motor and control method thereof

Abstract

The invention relates to a wheel hub motor and a control method thereof. The wheel hub motor comprises a motor shaft (1) and a stator (2), wherein a rotor shell (3) is sleeved outside the stator (2), and the front end and the back end of the stator (2) are rotatablely fixed on the motor shaft (1) through a rotor end cover (4) and a bearing (5); the outer side of the rotor end cover (4) is connected with a hub brake component (9); the rotor shell (3) is connected with a wheel hub (6); a position detection device is arranged at a position corresponding to the wheel hub motor, and comprises a retainer (7) which is fixed on the motor shaft (1) and a magnetic steel ring (11) which is fixed on the rotor end cover (4); a plurality of Hall elements (10) are arranged on the retainer (7); a servo controller (18) is arranged on the motor shaft (1); and the rotor end cover 94) and the motor shaft (1) rotate relatively. The wheel hub motor is simple in structure, energy-saving, high in starting characteristic, small in size, and high in efficiency.

Description

technical field [0001] The invention relates to a hub motor and a control method thereof, in particular to a hub motor with a position detection device applied to an electric bicycle and a control method thereof. Background technique [0002] With the development of the economy and the improvement of people's living standards, electric vehicles such as electric mopeds, electric bicycles, electric motorcycles, small electric cars, electric cars, and electric buses are gradually emerging in urban traffic. As a new generation of electric vehicles, electric wheel vehicles need to improve the hub motor, a key component, in order to improve performance and reduce costs. [0003] The operating characteristic of the drive motor for vehicles is that the motor is powered by the battery, and strives to enable the limited energy to travel the longest mileage, which is closely related to the performance of the drive motor. Therefore, the starting torque of the motor, the overload capaci...

AI Technical Summary

Problems solved by technology

However, the magnetoelectric position detection device has the following disadvantages in physical structure: the inner side of the stator is generally arc-shaped and smooth, the sensor is not easy to install and fix, and it is easy to cause positioning errors, which in turn causes the phase deviation of the signal, making the high-order harmonics in the signal The weight is large; the manufacturing process is complicated, which is not conducive to industrialization; the reliability is low, the sensors are evenly distributed on the inner wall, and the supporting substrate of the sensor must be a flexible body, such as: FPC, etc., but its tensile strength is not high, easy to break, and increases It increases the difficulty of processing and affects the life of the product; at the same time, the magnetic field induced by the sensor leaks a lot, and the magnetic field cannot be fully applied, which makes the noise in the signal large and affects the measurement accuracy; the overall structure of the product requires the sensor to be small, which makes the product cost relatively high

In this process, what the position sensor detects is not the absolute mechanical position of the motor rotor; and the output control signal is a square wave, which cannot realize pure sinusoidal current control of the motor, resulting in low operating efficiency of the motor and relatively small output torque of the motor. Thereby greatly affecting the performance of the motor

[0010] In the prior art with the publication number of US6201389B1, the principle of the invention is also that when there is relative motion between the magnet steel and the Hall magnetic sensor, the change of the magnetic field induced by the Hall magnetic sensor is converted into an analog voltage output, but in this invention the analog The voltage signal is directly input to the CPU through AD conversion. This signal processing method has weak anti-interference ability. When the external environment and conditions change, it may interfere with the analog voltage signal, resulting in inaccurate detection data received by the CPU.

[0011] In the prior art with the publication number WO2008043421A2 / WO9506971A1, the structure and installation method of the invention are relatively complicated, and the installation space of the position detection device in the hub motor is limited, so the stability and reliability of the invention when applied to the hub motor will be affected

In addition, when considering the mass production of hub motors, the production process and cost of the invention are also a big problem

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