Hydraulic transmission gearbox, also known as hydraulic transmission, is a device that uses hydraulic power to transmit torque and rotational motion between two shafts. Hydraulically driven gearboxes are widely used in heavy-duty vehicles, construction machinery and marine applications for their high efficiency, ease of control and reliability. The hydraulic transmission gearbox is usually composed of hydraulic pumps, hydraulic motors, gear sets, hydraulic valves and other components.