Many different types of hydraulic pumps are available to consumers. Some of the more common types of hydraulic pumps are gear pumps, vane pumps, axial piston pumps, radial piston pumps and gerotor pumps.
There are several components that go into any hydraulic pump. These vital components are the reservoir, valves, pump and actuator. The main purpose of a hydraulic reservoir is to hold a given volume of fluid, transfer heat, allow contaminants to settle and facilitate air and moisture release from the fluid. Pumps displace fluid volume against resistant loads or pressures. Valves start and stop the unit, as well as direct fluid flow. Actuators convert hydraulic energy back into mechanical energy.
Each kind of hydraulic pump offers several different benefits. Gear pumps and vane pumps are both generally considered to be simple and cheap. Vane pumps are good for higher-flow, low-pressure output. Axial piston pumps include a variable displacement mechanism that allows varying output flow for an automatic control of pressure. Radial piston pumps are typically used for high-pressure at low-flow. The gerotor pump is very efficient for a medium pressure pump.
Consider several aspects of hydraulic pumps before employing their use. Vane pumps are the least efficient because they work at a constant displacement. Axial piston pumps are disadvantaged in that they are more sensitive to oil contamination than many other hydraulic pumps.
Different hydraulic pumps are manufactured to produce a maximum amount of pounds per square inch (psi). A "bar" is a unit of measurement used to gauge pressure; 1 bar is equivalent to 100,000 newtons per square meter. Gear pumps and vane pumps are mainly suitable for producing pressures under 200 bars, which is comparable to 3,000 psi. Axial piston pumps can produce pressures around 350 bars. Radial piston pumps can produce pressures up to 650 bars.