A direct-drive elevator motor where a permanent magnet synchronous motor drives the traction sheave directly without an intermediate gear reduction, offering high efficiency at all speeds.
Full Definition
A gearless traction machine couples a permanent magnet synchronous motor (PMSM) directly to the drive sheave shaft, eliminating gear mesh losses. PMSM motors use embedded rare-earth magnets (neodymium) on the rotor and a wound stator, producing high torque at low rpm with efficiencies of 90–95 % compared to 70–85 % for worm gear machines. The compact disc-shaped (pancake) form factor enables MRL installations. Torque is controlled precisely by the VVVF drive, allowing smooth S-curve acceleration and deceleration. With no gearbox oil, maintenance requirements are significantly reduced — periodic tasks are limited to brake adjustment, guide shoe checks, and encoder cleaning. Gearless machines operate at speeds from 1.0 m/s to 10 m/s, making them the standard for mid-rise to high-rise traction elevators. EN 81-50 type examination covers the complete traction machine including brake and sheave.
