Rotor problems in permanent magnet motor applications

Different motor products have different advantages and applicability. Due to different working conditions, the requirements for motor product parts are also different. For example, for heavy-load working conditions, there are special requirements for motor bearings and shafts. For places with dense personnel, the vibration and noise requirements of the motor are relatively strict; when the environment is dusty, the protection level of the motor must meet the necessary protection requirements. Under the guidance of the overall policy of energy conservation and low carbon, the market prospects of high-efficiency motors are relatively optimistic. However, for permanent magnet motors with relatively high efficiency levels, due to some specific failure factors, there are certain limitations in their application in some specific occasions. One of the more typical problems is the demagnetization or shedding of the rotor magnet. We have also had a special discussion on the demagnetization problem of permanent magnet motors. The main reasons are high temperature and high current. The high temperature problem may be related to the design and application of the motor itself, but a factor that cannot be ignored is the motor's bore sweeping problem. When the motor has a bore sweeping problem, it will cause severe heat due to the friction between the stator and the rotor, which will directly lead to the demagnetization of the magnet. When the magnet loses magnetism, the reliability of the connection with the fixed bracket will deteriorate, and the problem of magnet shedding will derive.

Regarding the problem of magnetic steel falling off, in addition to the connection reliability caused by demagnetization, the centrifugal effect during motor operation is also a key factor. Therefore, the degree of fit between the magnetic steel and the mating surface of the substrate, the performance compliance of the adhesive, and the necessary mechanical stability measures are all important contents of the permanent magnet motor magnetic steel fixation. Some motor manufacturers will use the inlay method to fix the magnetic steel on the bracket and take necessary bonding and fastening measures; some manufacturers will use bonding and ring fixing methods to fix it. Especially for high-speed motors, the magnetic steel fixing technology is particularly important. If the problems of permanent magnet motor demagnetization and magnetic steel fixing can be solved, the high-efficiency advantage of permanent magnet motors will be more obvious.
low voltage electric motor, Ex motor, Motor manufacturers in China, three phase induction motor, Wolong Nanyang Explosion Protection