The electromechanical unit comprising a motor, brake, gearbox or gearless drive, and step-chain sprocket that provides motive force to drive the steps and handrail of an escalator.
Full Definition
The escalator drive machine is the heart of the escalator system. Components: (1) Drive motor — typically an AC induction motor or, in modern escalators, a PMSM with VFD for soft starting and energy-saving slow-speed operation at low demand; (2) Gearbox — helical or worm gear reducer; gearless machines use direct-drive PMSM; (3) Operational brake — electromagnetic disc or drum brake, de-energised to hold the escalator stationary, released during normal running; (4) Drive sprocket — main chain wheel engaging the step chains; (5) Handrail drive — friction roller or toothed belt connecting the main shaft to the handrail loop. EN 115-1 requires two independent braking systems: the operational brake and a secondary step-chain brake. The machine is located in a machine space (typically at the upper landing) accessible only to authorised personnel. MRL escalators integrate the drive machine compactly within the truss.
