Radial Piston Pump (from Internet Glossary of Pumps)
Radial Piston Pump
Radial Piston Pumps can produce a very smooth flow under extreme pressure. Generally they are variable-displacement pumps.

In variable models, flow rate changes when the shaft holding the rotating pistons is moved with relation to the casing (in different models either the shaft or the casing moves.) Output can also be varied by changing the rotation speed.

In this animation if the casing (shown in red) is moved to the left, the flow rate would decrease to zero. If it is moved even further to the left the flow would reverse.

Input in this animation is through the TOP two black holes near the center below the "Pintle" (shown in yellow). Output is through the BOTTOM two black holes, above the pintle. Higher pressure areas are indicated with a DARKER blue fluid color.

The pistons are usually forced out by springs. They are forced back in, expelling liquid, by the casing.

An odd number of pistons is always used to smooth the hydraulic balance. These pumps revolve at speeds up to about 1200 RPM.

Note similarities to, and differences from, the wobble pump, swash plate pump, and bent axis pump.

(This is an 10-frame animation, converted to animated GIF format for Internet transmission. (Note: On some Internet browsers it may be displayed much less smoothly than the CD-ROM version, where the frames are timed to a thousandth of a second.))


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Last modified February, 2002
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