Fluid power

Fluid power is conventionally subdivided into hydraulics (using a liquid such as mineral oil or water) and pneumatics (using a gas such as compressed air or other gases).

A fluid power system has a pump driven by a prime mover (such as an electric motor or internal combustion engine) that converts mechanical energy into fluid energy, Pressurized fluid is controlled and directed by valves into an actuator device such as a hydraulic cylinder or pneumatic cylinder, to provide linear motion, or a hydraulic motor or pneumatic motor, to provide rotary motion or torque.

Dynamic (non positive displacement) pumps This type is generally used for low-pressure, high volume flow applications.

These pumps are capable of overcoming the pressure resulting from the mechanical loads on the system as well as the resistance to flow due to friction.

Fluid motors normally produce no sparks, which are a source of ignition or explosions in hazardous areas containing flammable gases or vapors.

Fluid power systems are susceptible to pressure and flow losses within pipes and control devices.

Any dirt in the system can cause wear of seals and leakage, or can obstruct control valves and cause erratic operation.

A very compact fluid power system is the automatic transmission found in many vehicles, which includes a hydraulic torque converter.

Variable-flow control valves and position sensors may be included in a servomechanism system for precision machine tools.

[citation needed] Combinations of electrical control of fluid power elements are widespread in automated systems.