Three ways to move fluid
Gear pumps carry fluid in spaces formed by rotating gears and the housing. Vane pumps use moving vanes in a rotor to form pumping chambers. Piston pumps move fluid through the reciprocating action of pistons.
These names describe mechanisms, not universal performance rankings. Each family includes different designs, sizes and operating limits. Compare the actual datasheets rather than treating every pump of one type as equivalent.
Fixed or variable displacement
Displacement is the nominal volume moved per revolution. Fixed-displacement designs have a fixed nominal volume; variable-displacement designs can change it within their design limits. Changing shaft speed also changes theoretical flow.
Build a comparison that helps purchasing
Make a shortlist using the required flow, pressure, fluid, speed range, control method and installation envelope. Ask for the published operating limits and configuration for each candidate.
For Renowell enquiries, our catalog provides vane pump series and related components. This introduction to other pump types does not imply that all designs or configurations are available from Renowell.
References & further reading
Parker — Hydraulic Pump Basics ↗Educational material, not a model-specific operating or repair instruction. Use the applicable equipment and product documentation for the installation.