It is simply called a wheel. It doesn't have a official name
Sheave is another name for the entire pulley, rather than the indentation.
A pulley system is made up of a pulley and a rope. A pulley is, in essence, a wheel with a groove going all the way around it so that a rope or a cable can fit in it securely. One could also run an indented track around a wheel.
Pulley.
'A pulley'
The part of a pulley where the rope lies is called the groove or the sheave. This is the part of the pulley that provides the surface for the rope to run along while the pulley rotates.
This is called a pulley.
It is a idler pulley.
The middle part of a pulley is called the wheel or sheave. It is the round component that rotates on an axle and around which the belt or rope travels. The wheel is typically grooved to keep the belt or rope in place and provide a better grip for transmitting force.
That would most likely be a pulley. A pulley is essentially a wheel on an axle that usually has a groove in the middle of its circumference that holds a rope, cable, belt, or chain. Pulleys are used to transmit motion rotationally and apply force in the direction of said motion. Two or more pulleys makes a tackle. Hope this is what you were looking for.
Because wheel and axle pulley and gear are simple machines
A pulley is a wheel but not an axle.
there are two kinds of pulleys. A movable pulley and a fixed pulley. But a wheel and axle have a lever and a inclined plane. [someone] :]