Permanent magnet synchronous motor rotor assembly structure
Because of the high power factor, the three-phase asynchronous motor must make the air gap between the stator and rotor very small, and the uniformity of the air gap is also critical to the safe operation and vibration noise of the motor. The requirements for the geometrical tolerances of the components and the concentricity of the assembly are relatively strict, and the freedom of selection for the bearing clearance is also relatively small. The asynchronous motors of the larger bases usually use the oil-lubricated bearings, which must be in the specified work. When the lubricant is filled in time, the oil cavity leaks or the filling is not timely, the bearing failure will be accelerated. In the maintenance of the three-phase asynchronous motor, the maintenance of the bearing accounts for a large proportion. In addition, due to the presence of induced current in the rotor of the three-phase asynchronous motor, the problem of electrical corrosion of the bearing has also attracted the attention of many researchers in recent years.
Permanent magnet synchronous motors do not have such problems. Due to the large air gap of the permanent magnet synchronous motor, the related problems caused by the small air gap of the above asynchronous motor are not obvious on the synchronous motor. At the same time, the bearing of the permanent magnet synchronous motor adopts the grease-lubricated bearing with dust cover. The factory has been sealed with the right amount of high-quality grease, which is maintenance-free for life.
