Depending on the direction of fluid flow, hydraulic wheel motors can impel the wheels to move backward or forward.
Wheel motors are typically electric motors, but like any other hydraulic motor, hydraulic wheel motors provide power and rotation through the use of pressurized fluids. Hydraulic motors usually use pressurized oil as the hydraulic fluid. The oil is stored in a pressurized reservoir until the motor is to be used. When the motor is operating, the pressurized oil is released from the reservoir and enters into the motor itself.
Depending on the internal configuration of the motor, the oil will press against cylinders, pistons, gears, or other components. As the pressurized fluid presses against the cylinder or piston, the piston or cylinder moves and causes a shaft to rotate. With gears and other components, the pressurized fluid presses against and flows around the gears causing them to turn and rotate a shaft. In these ways, a hydraulic motor converts the energy of the pressurized fluid into mechanical energy.
A hydraulic wheel motor can operate a single wheel or multiple wheels, depending on the power of the motor and the size of the machine. In cases in which the motor supplies power to more than one wheel, the motor is connected to sprockets and each sprocket is connected to a wheel. Through this setup, power is distributed to the wheels. Hydraulic wheel motors can be used for many different applications. However, they see the most use in mobile construction equipment.