Hydraulic Terms R speaks to hydraulic phrases R and hydraulic glossary R which are in common use in the hydraulic industry.
Radial Piston Pump The
pumping mechanism of this pump basically consists of a cylinder barrel,
pistons with shoes, a ring and a valve block. The action of a radial piston
pump is quite similar to a vane pump but instead of using vanes to track
along a ring, the pump uses pistons.
Ram A hydraulic mechanism that uses the kinetic energy of a flowing liquid to force a small amount of the liquid to a reservoir contained at a higher level.
Reservoirs The size of a reservoir will depend on the capacity of the hydraulic system, as well as what is required by the system. The reservoir should contain a large volume of oil and should provide ample oil to the pump.
Resistance In hydraulics, the condition engendered by an obstruction or restriction in the flow path.
Return Line Filter A return line filter is positioned in the circuit just before the reservoir. Range of filtration usually found in return line filters is from 40 to 50 micrometers.
Reverse Flow A normal requirement of all pressure valves, except relief and unloading valves, is that reverse flow must be able to pass through the valves.
Rotary Positive Displacement Pump The most common positive displacement pump in a machine’s hydraulic system is not a reciprocating plunger but a rotary type. This pump develops a relatively smooth, pressurized flow of liquid and can easily be driven by an electric motor or gas engine. For each revolution the pump is rotated a definite volume of liquid is moved.
This pump consists of a housing with inlet and outlet ports and a rotating group which develops fluid flow and pressure. One type consists of a rotor and vanes which are free to move in and out. The rotating part of the pump is positioned off center to the housing. The rotor is connected to a prime mover by means of a shaft. As the rotor is turned, the vanes are initially thrown out by centrifugal force and contact the housing forming a positive seal.
The increasing volume at the inlet side allows liquid to fill the pump. The decreasing volume at the outlet forcefully pushes the liquid out to the system. The amount of pressure applied to the liquid by the pump will only be as great as the least resistance to flow in the system.
Rust and Oxidation Inhibitors These are the basic hydraulic oil additives used for most industrial systems and are referred to as R&O oils. The high grade is turbine quality. Low grade R&P pils is suitable for many hydraulic applications and is known R&O less than turbine quality.