An escalator is a stationary, electrically driven device equipped with continuously circulating steps, designed to transport passengers upward or downward along an incline.
An escalator consists of a stepway (a modified plate conveyor) and handrails located on both sides (a modified belt conveyor). Its primary components include the steps, traction chains and sprockets, guide rail system, main drive system (comprising the electric motor, speed reducer, brake, and intermediate transmission linkages), drive shaft, stepway tensioning device, handrail system, comb plates, escalator truss, and electrical system. At the passenger entry point, the steps move horizontally (facilitating easy boarding for passengers) before gradually forming a staircase; as they approach the exit, the staircase configuration gradually disappears, and the steps resume horizontal movement. These movements are achieved through the interaction of the steps' main wheels and auxiliary wheels, which travel along distinct sets of guide rails.
