The pinion gears connect the shaft of the motor to the wheel.
A pinion is a gear that rotates around an axle. A crown is the part of a gear that touches the axle. Up until now, I have only discussed the outside of a gear. I now need to go inside a gear.
The pinion gears and the crown rotate to turn the mill. The
pinion gears are the axle that fits into the center of the axle shaft. They are made of steel or iron and are shaped like a gear. The crown is the part of the mill that rotates when the user turns the handle.
Crown and a Pinion are used to measure torque.