Glossary and index of fluid power principles and components R
A cylinder that has an extend port only. Usually accompanied by auxiliary cylinders that are mechanically linked to the ram to facilitate retraction action.
The rate of change of a specific output, such as the ramp of a pressure compensator.
An electronic device that controls the rate of rise of a servo or proportional valve by using capacitors to limit the rate of voltage or current change to the servo or proportional valve.
The maximum flow that a manufacturer assigns to a specific component as the maximum desirable flow at which the device will function properly. Also the flow that a designer assigns to a system as the nominal maximum flow. See WORKING PRESSURE.
The maximum pressure that a manufacturer assigns to a specific component as the maximum desirable pressure at which the device will function properly. See WORKING PRESSURE.
Back-and-forth straight line motion or oscillation.
A valve that decreases the downstream pressure (at the valve outlet) in order to control the flow and therefore the outlet pressure to some preset level. Normally accomplished by balancing the outlet pressure against a precision spring.
A piping arrangement for a differential type cylinder in which discharge fluid from the rod end combines with pump delivery to be directed into the head end.
A term used to describe a valve or device that limits the pressure in a passage.
The strengthening members, consisting of fabric, cord, and/or metal, of a hose.
An electromagnetic device that allows one circuit to control another without a direct electrical connection between the two circuits.
A system for controlling a machine or process based on the status of various interconnected relays.
A valve that limits the pressure at its inlet port by exhausting flow present at its inlet port to another chamber of lower pressure potential through its outlet port.
To add fluid to maintain a full hydraulic system.
A chamber used to store fluid.
The opposition to current flow offered by the components of an electrical circuit.
The elapsed time that occurs after the beginning of a function until its completion. For example, the time elapsed between application of electrical power to a solenoid and its full excursion or stroke.
A reduced cross-sectional area in a line of passage producing a pressure drop.
A passage that is used to route fluid to a reservoir or tank after use in some function. Normally limited to low pressures of 0-150 psig, but may be higher in special applications if so designed.
A four-way directional valve used to reverse a double-action cylinder or reversible motor.
The Rubber Manufacturers Association, Inc.
A hydro-mechanical device that converts fluid flow into incremental rotary motion as compared to a fluid motor which produces infinite numbers of turns. See FLUID MOTOR.
A connector or fitting that is equipped with seals or o-rings that allow it to rotate while passing one or more fluid paths through sealed internal passages.
ROTARY VARIABLE DIFFERENTIAL TRANSFORMER (RVDT)
An electro-mechanical rotary device that produces an analog signal in proportion to the difference in distance between a magnet and a separate fixed coil.
ROTARY VARIABLE TRANSFORMER (RVT)
An electro-mechanical rotary device that produces an analog signal in proportion to the difference in velocity between a magnet and a separate fixed coil.