A machinery system, in general, consists of a prime mover, a power transmission, and an implement end-effecter. The prime mover is used to convert the energy of various potential forms into the mechanical form to provide the needed power to drive the machinery, the implement end-effecter is created to perform the designated work, and the power transmission is designed to deliver the regulated power from the prime mover to the endeffecter. For example, an automobile uses an internal combustion engine to convert potential chemical energy carried in the fuel into mechanical power. A mechanical power transmission mechanism then delivers and regulates the power to the wheels to drive the vehicle at a desired speed. An electrical ceiling fan uses an electric motor to convert electrical energy, delivered using an electrical power line, into mechanical power to drive the fan. A hydraulic jack converts biological energy carried by a person into mechanical power via a hand pump to lift a heavy automobile. One may find that there is something in common among these three examples: all three devices convey a certain amount of power using mechanical parts, electricity, or pressurized fluids, from the prime mover to drive the end-effecter to perform the designated functions. These examples illustrate three basic methods of power transmission: mechanical, electrical, and fluid power transmissions.