Novel high-power permanent magnet brushless motor

Abstract

The invention discloses a novel high-power permanent magnet brushless motor, comprising a pedestal, a stator, a rotor, a bearing and a position sensor device, wherein the two ends of the pedestal are respectively provided with a front end cover and a rear end cover; the stator, the rotor, the bearing and the position sensor device are respectively arranged in the pedestal; the rotor further comprises a rotor magnet steel, a rotor iron core and a rotary shaft; the rotor iron core is sheathed outside the rotary shaft; the rotor magnet steel is sheathed outside the rotary shaft and the iron core; the rotor magnet steel comprises a plurality of magnet steels with different polarities; and the magnet steel on each magnetic pole is in a block type structure and comprises more than two small pieces of magnet steel in the circumferential direction. With the adoption of the novel high-power permanent magnet brushless motor, the shortcomings that the rotor magnet steel is easy to emit heat and crush while the face pole type magnetic steel inner rotor runs at high speed and easily degausses caused by NdFeB magnet steel, leading out and connection of the signals of the position sensor device are tedious, and the bearing is easily damaged and processing waste of the cambered magnetic steel is large, so that the manufacturing cost of the high-power permanent magnet brushless motor is reduced, the reliability is improved, and the service life is increased.

Description

technical field [0001] The invention relates to the field of motors, in particular to a novel high-power permanent magnet brushless motor. Background technique [0002] Permanent magnet brushless DC motor has been widely used in electronic information, automation and national defense equipment because of its superior speed regulation performance and high energy conversion efficiency. However, limited to the price and performance of permanent magnet materials, as well as factors in motor design and process technology, currently only some low-power permanent magnet brushless DC motors are generally produced. [0003] The permanent magnet brushless DC motor is mainly composed of three parts: the permanent magnet brushless DC motor body, the position sensor device and the electronic driver. The motor body is composed of a stator and a rotor, and its structure is similar to that of an AC permanent magnet synchronous motor. The main difference between it and an AC permanent magne...

AI Technical Summary

Problems solved by technology

[0013] The bearings of permanent magnet brushless motors are more easily damaged than those of ordinary power frequency asynchronous motors

The first reason is that the PWM voltage output by the electronic driver causes the magnetic field inside the motor to be asymmetrical, which will induce a voltage between the motor shaft and the end cover, and this voltage will be completely applied to the inner and outer rings of the bearing; the second is the permanent magnet motor It is easy to magnetize the bearing during assembly, and the voltage generated between the inner and outer rings of the bearing is caused by high-speed rotation

When the voltage value generated between the inner and outer rings of the bearing exceeds the dielectric strength of the lubricating oil in the bearing, it will break down the oil film to form a current path, resulting in electrochemical corrosion of the balls and raceways, resulting in a rapid shortening of the bearing life

[0014] To sum up, the main obstacles restricting the large-scale permanent magnet brushless DC motor are: 1. When the motor is running at high speed, the strength of the rotor is limited by the strength of the magnetic steel and the connection strength, and the magnetic steel is prone to cracking and falling off (except for the outer rotor); 2. 1. Large pieces of magnetic steel are easily demagnetized by the dual effects of temperature and demagnetization field; 3. There are many lead wires for the signal of the position sensor device, and the connection is cumbersome; 4. The bearing life is short

[0015] Due to the above problems, the current high-power permanent magnet brushless motors have encountered great obstacles in the manufacture and promotion

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