As part of the elevator pulley system, the motor sheave -- in coordination with a counterweight -- hoists the elevator car in one direction and lowers in another direction similar to a see-saw.
The sheave is powered by the control system housed on top of the elevator car. The traction ropes of the elevator are looped around the sheave. Power is supplied by the motor. The energy supplied activates the counterweight, causing the sheave to rotate and elevate or lower the elevator car.
Unlike roped and gear-less elevators, a gear train rotates the sheave in geared elevators.
