China is the largest manufacturer, consumer, and exporter of elevator. Basing on the market survey from China Elevator Association, elevator power consumption has already reached 5% of the entire building’s power consumption which means elevator became one of the largest energy consumption equipment in high-rise buildings. Elevator with permanent magnet synchronous traction machine has occupied the market mainstream, therefore, demand for elevator traction machine magnets still very high.
Traction type elevators consist 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 operate. Traction machine composes 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 base on 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. Permanent magnet gearless traction machine is widely served to elevator industry due to its small size, smooth running during low speed, maintenance-free, low energy consumption, and less noise.
High performance Neodymium magnets are one of the core components in the elevator traction machine. As the excitation source of traction machine, irreversible flux loss of magnet 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 in a certain historical period.
