Product: Pump
Springy variable displacement piston pump   (+1)  [vote for, against]
Inspired by [pashute]'s Servo powered permamagnet motor

The rotor has magnets spaced around it, the same pole facing towards the outside. As the rotor magnets move past a piston, they repel the piston due to its embedded magnet.

The distance between the piston and the rotor can be adjusted by supporting the piston with some adjustable- location magnets, which repel some piston-embedded magnets added for this purpose.

Changing this distance adjusts the stroke length of the pump.

For use as a pump you can use way valves.

If you use cams to control the valves you can run it as a hydraulic motor or as a pump.
-- caspian, Jul 12 2015

Illustration http://www.sockstar...ent-piston-pump.png
[caspian, Jul 12 2015]

Servo powered permamagnet motor Servo_20powered_20permamagnet_20motor
Inspiration for this idea [caspian, Jul 12 2015]

I like.
-- MaxwellBuchanan, Jul 12 2015

random, halfbakery