A winch motor is the component of the winch that actually powers the cable, rope or chain. Typically electrical, air or hydraulically-powered, the winch motor is responsible for not only the pulling power of the winch, but quite often the motor is also tasked with powering the cable, rope or chain out or off of the winch. On large, overhead winches used in manufacturing plants, the winch motor may be as large as a small car and operate on extremely high electric voltage. On vehicle-mounted winch applications, the motors are commonly powered by 12-volt, automobile-type batteries and typically resemble the starter motor for an automobile engine.
The pulling and lifting capacity of a winch is generally decided by the strength of the winch motor. Working through a series of reduction gears, the often high speed of the electric winch motor is converted to torque and pulling strength. This allows the winch motor to work without severe stress and strain, similar to the gears on a bicycle allowing a rider to climb a steep hill without tiring or getting off of the bike. The use of the gearbox also allows the use of much smaller motors that would otherwise be required to move the heavy loads.
While the electric style of motor actually makes the power to turn the gear box and ultimately the winch, the air and hydraulic motors are, in reality, small transmissions in themselves. As air is used to power a winch, the air is forced over gear paddles that, in turn, move other gears. The air, however, does not create any power; it is simply a tool to move the gears in the motor. The same can be said for the hydraulic winch motor. Hydraulic fluid is passed over gear sets in the same manner that air is, and this creates the motion inside of the gear box to move the winch.
Many large, industrial-type winches use very large electric motors to power the winch. These motors are often linked to the winch by a series of rubber belts and pulleys. These large units also use a gear reduction box to increase the power of the winch. On smaller, vehicle-mounted winches, however, the winch motor is often a direct drive motor and is actually attached to the transmission gears through the use of a coupler. This prevents any chance of slippage due to wet or debris-covered belts or gears.