Permanent magnet reluctance type in-wheel motor

Abstract

The invention relates to a permanent magnet reluctance type in-wheel motor, which comprises an outer rotor and an inner stator, wherein a three-phase winding is arranged on the inner stator; magnetic steel is uniformly distributed along the circumferential direction of the outer rotor; the permanent magnet reluctance type in-wheel motor is characterized in that grooves arranged at intervals are formed on the inner circumferential surface of the outer rotor; the magnetic steel is embedded inside the grooves; the cross section of the magnetic steel is rectangular; the polarity of all magnetic steel facing to the inner stator is the same; a magnetic conduction salient pole is formed between adjacent grooves; the magnetic conduction salient poles and the magnetic steel are arranged alternately at intervals; the curve of the cross section of the magnetic conduction salient pole facing to one side end of the inner stator is convex arc-shaped; and the number of grooves and the number of magnetic poles in the outer rotor adopt the combination with close grooves. The permanent magnet reluctance type in-wheel motor has the advantages that the using amount of magnetic steel can be efficiently reduced and the output of reluctance torque is improved under the precondition of not increasing process complexity; and the magnetic conduction salient poles adopt arc-shaped convex surfaces, so that the motor torque pulsation is efficiently reduced, the stability of motor running is ensured, and the product reliability is improved.

Description

technical field [0001] The invention relates to a permanent magnet reluctance motor, in particular to a permanent magnet reluctance outer rotor hub motor applicable to electric bicycles or electric motorcycles. Background technique [0002] The permanent magnet motor uses permanent magnets to generate the magnetic field of the motor. It does not require excitation coils or excitation current. It has high efficiency and simple structure. It is a good energy-saving motor and is often used as the first choice for driving electric bicycles. [0003] In 2012, the number of electric bicycles in China reached 140 million, and the annual growth rate is about 30 million. Ordinary electric bicycles mainly use the outer rotor brushless DC hub motor, which adopts a surface-mounted hidden pole structure, such as the rotor structure disclosed in the Chinese utility model patent "Electric Wheel Hub Motor" with the patent number ZL200820082308.5. This type of hidden pole motor The torque i...

AI Technical Summary

Problems solved by technology

Ordinary electric bicycles mainly use the outer rotor brushless DC hub motor, which adopts a surface-mounted hidden pole structure, such as the rotor structure disclosed in the Chinese utility model patent "Electric Wheel Hub Motor" with the patent number ZL200820082308.5. This type of hidden pole motor The torque is derived from the electromagnetic torque, so a large amount of rare earth permanent magnets are required. The magnets required by this patent are closely pasted with N poles and S poles alternately. In fact, the adjacent areas where the two kinds of magnets are closely pasted The magnetic force lines are directly connected without coupling to the rotor, and the brushless motor realizes a 120° conduction mode, so it is a waste to place the magnetic steel closely, but the production process of the magnetic steel mounting is simple

Another example is the Chinese utility model "Adhesive magnetic steel ring between rotors of electric vehicle motor" with patent No. 201020049324.1, which discloses such a structure. It is proposed to use the boss to control the installation of the magnetic steel. Although the amount of the magnetic steel is reduced, the motor cannot be driven by the reluctance torque.

[0004] In addition, the Chinese invention application "Electric Vehicle Motor" with the application number of 201110061396.7 discloses a method for reducing the amount of magnets used in brushless motors of electric vehicles, reducing the number of magnets by half, and only installing magnets of the same polarity. Using the salient pole magnetically conductive convex body, it is claimed that the amount of magnetic steel can be greatly reduced, but this method is specified to be used for brushless motors. The operation of brushless motors requires a certain amount of magnetic flux, and the air gap magnetic flux density must meet the requirements for torque generation. The permanent magnet is used as the excitation source, and only one polarity of the magnet is used. The magnet must be thickened and widened. The actual saving effect may not exceed the former; secondly, the magnetic circuit of the patented motor is no longer symmetrical , has the ability to generate reluctance torque, but the patent does...

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