What Is the Purpose for a Motor Sheave?

The motor sheave, a small part of the cable system of roped and gear-less elevators, regulates the movement of the elevator car.

Purpose

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.

Mechanism

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.

Difference

Unlike roped and gear-less elevators, a gear train rotates the sheave in geared elevators.

References

• Smartelevators.com: How Elevators Work