China is the largest manufacturer, consumer, and exporter of elevator. China Elevator Association calculates that elevator power consumption occupies 5% of the entire building’s power consumption and that means the elevator is one of the largest energy consumption equipment in high-rise buildings. PM synchronous motor has occupied the market mainstream, therefore, demand for elevator traction machine magnets also remains very high. Traction type elevator consists of traction system, guidance system, gate system, car, balance system, the electric drive system, power control system and safety protection system. Traction machine transports and transmits power to make the elevator system to work. Traction machine is composed of the motor, brake, coupling, reduction gearbox, traction sheave and guide wheel. Traction machine can be classified to direct current (DC) traction machine and alternating current (AC) traction machine according to the motor type, then AC traction machine can be further divided to AC gear traction machine, AC gearless traction machine, and permanent magnet traction machine. Actually, PM gearless traction machine is widely served to elevator industry due to small size, smooth running during low speed, maintenance-free, low energy consumption and noise.

High performance sintered Neodymium magnet is one of the core components in the elevator traction machine. As the excitation source of traction machine, irreversible flux loss of sintered Neodymium magnet caused by different reasons will bring potential security risks to the entire elevator system. Elevator traction machine magnets are generally adopting N35SH, N38SH, N40SH and N33UH grade. To some extent, the explosive growth of elevator traction machine stimulates the development of high coercivity Neodymium magnet over a period of time.