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.
Each type includes different designs, sizes and operating limits. Compare the actual datasheets when choosing between them.
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.
Compare models for your application
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 available Renowell series and configurations, see the product catalog. This article also covers pump types beyond that range.
References & further reading
Parker — Hydraulic Pump Basics ↗For operating limits and service procedures, use the document for your exact pump and machine.