Simple gears are used to transfer power from one shaft to another, but when the shafts intersect at odd angles, they don’t intersect at all, or you need to change rotational direction of a shaft, things become complicated. It takes a bevel gear to keep things moving. Bevel gear design is commonly used in many industrial applications as well as in all types of vehicles.
On a standard gear, the pitch surface (that carries the teeth) is cylindrical. On a bevel gear, the pitch face is conical. The angle formed by the pitch pace and the axis on which it’s mounted to is called the pitch angle. Often, bevel gears work at right angles, but they can be designed to function at any pitch angle. A hand drill is an example of a tool that uses a 90o bevel gear.