CPC F04B 49/002 (2013.01) [F04B 27/18 (2013.01); F04B 49/06 (2013.01); F04B 49/103 (2013.01); F04B 49/08 (2013.01)] | 17 Claims |
1. An electric motor pump system, comprising:
a variable displacement pump;
an electric motor connected to drive the variable displacement pump;
a first control piston configured to limit an output pressure characteristic of the pump; and
a second control piston controlled via a servo valve according to an output speed of the electric motor, the second control piston being configured to maintain a constant output flow of the variable displacement pump as the output speed of the electric motor changes;
wherein the first control piston and the second control piston have different diameters; and
wherein the first control piston and the second control piston act on a yoke of the variable displacement pump to vary the displacement of the variable displacement pump.
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