Hydraulic Drive Motors

Hydraulic drive motors are used in hydraulic systems or transmissions to generate large amounts of power through use of hydraulic fluid and pressure. The motor is one component of a three part system that uses a hydraulic pump driven by an electric motor or combustion engine to force hydraulic fluid such as oil through the valves, filters and piping to enter the motor and cause the motor to generate torque and rotational energy.

The hydraulic system hydraulic drive motors are apart of can also be called a hydrostatic drive system, referring to the transfer of energy from flow and pressure. Hydraulic motors of any size are able to produce greater amounts of power than their electric counterparts and for this reason are used for large loads. The main enclosure and interior components are made from metal such as steel or iron so they can withstand high pressures and operating speeds.

Hydraulic drive motors and the systems they are a part of are widely used in aircraft, vehicles, industrial lifting and in machinery that requires strong pressurized actions. Hydraulic motors, when used in a suitable system, are able to accomplish large amounts of work in short periods of time. Additionally, hydraulic motors are frequently used in automated manufacturing systems, trenchers, automobiles, construction equipment, drives for marine winches, waste management and recycling processes, wheel motors for military vehicles, self-driven cranes, excavators, forestry, agriculture, conveyor and auger systems, dredging and industrial processing.

There are three main kinds of hydraulic drive motors: gear, vane and piston. Each uses a different method to generate power while still relying on the use of hydraulic fluid. Hydraulic drive motors are mechanical actuators because they are the components that come into contact with the fluid and do the work of generating energy.

Rol-Seal Hydraulic Motor
Hydraulic Drive Motors – Von Ruden Manufacturing, Inc.

The motor is driven by a small pneumatic engine that pumps oil from a reservoir through an inlet valve to an outlet valve through a series of gears, rotating screws, turning vanes or cylinders, depending on what specific type of hydraulic motor it is. The fluid causes the rotating components to turn quickly which generates mechanical energy because the motor is linked to other machinery through a drive shaft, for example.

After traveling through the motor, the hydraulic fluid is filtered and returned to the main tank in an open system or continues in one pressurized loop in a closed system. Heavy duty valves are required to control the high pressure present in the system; this pressure is able to convert as little as 4.5 pounds of input force into 100 pounds of load moving force and that ability is only for a basic foot pump. Other hydraulic motors are able to provide forces of millions of metric tons with this simple system.