Definition - What does Sheave mean?
A Sheave is a pulley that has a grooved wheel inside a frame. The groove holds a wire rope or a belt that is used for lifting loads or transmitting power. As the rope in the groove is pulled, the wheel spins making the rope to move freely thus minimizing the wear and abrasion of the rope. Its applications include the lifting of a water bucket from a well or lifting loads through cranes.
Petropedia explains Sheave
Pulley systems are mainly used for lifting loads, power transmission or changing the direction of the force to be applied. A sheave, an example of a pulley system, consists of a grooved wheel which can spin inside a frame. The groove holds a rope, wire rope or a belt which can be used to transmit force or power to lift the load. When the force is applied on one end of the rope with load on the other end of the rope in the groove of the wheel, the wheel spins causing the rope to move freely. The force needed to lift the load is much less and can conveniently be applied in any suitable direction.