Using high-performance rare earth permanent magnet materials, no carbon brushes, permanent magnet synchronous gearless traction machine can drive efficiency up to 90%. It effectively improves the energy efficiency with energy saving, environmental protection, low speed and high torque characteristics. Gearless traction machine can be dividedinto the inner rotor and outer rotor based on the rotor structure, whilepermanent magnets stick to these rotors.

Due to the special work environment of the elevator, it is possibility that magneton the motor will demagnetize after prolonged use, for example:
1. Unqualified rare earth permanent magnet;
2. Unsaturated magnetization;
3. Motor working temperature exceed magnet permitted range;
4. Long oxidation of rare earth permanent magnet;

In orderto avoid the above situation occurs in practice, the elevator magnets needs careful and meticulous design and manufacturing. Magnet design also needs to consider magnet size, magnetic properties and the worst working conditions of motor. It is better that the magnetic properties are higher than the practical requirement. Before installation, rare earth permanent magnets should pass high temperature aging test and saltspray test.

For a long time, elevator manufacturers use bonding process to fix permanent magnets on the rotors. Theoretically, using glue and magnetic force, it could be okay. But In some cases magnets will tear off because of high temperature or other reasons. To reinforce magnet on the rotor and reduce the problems caused by magnet dropping, it can combine screws and adhesive binding by making a countersunk on the basis of simple block or arc magnets.