US 11,692,541 B2
Electric motor pump system and method
Charles Shand, Southampton (GB); Mark D. Stacey, Portsmouth (GB); Simon Orde, Bognor Regis (GB); Steven C. Birch, Portsmouth (GB); Stephen Devan, Madison, MS (US); Phillip Galloway, Madison, MS (US); Douglas Scott, Brandon, MS (US); and Daniel Chapman, Flowood, MS (US)
Assigned to Eaton Intelligent Power Limited, Dublin (IE)
Appl. No. 17/255,115
Filed by Eaton Intelligent Power Limited, Dublin (IE)
PCT Filed Jun. 28, 2019, PCT No. PCT/EP2019/067353
§ 371(c)(1), (2) Date Dec. 22, 2020,
PCT Pub. No. WO2020/002612, PCT Pub. Date Jan. 2, 2020.
Claims priority of provisional application 62/691,925, filed on Jun. 29, 2018.
Prior Publication US 2021/0270258 A1, Sep. 2, 2021
Int. Cl. F04B 49/00 (2006.01); F04B 49/06 (2006.01); F04B 49/10 (2006.01); F04B 27/18 (2006.01); F04B 49/08 (2006.01)
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
OG exemplary drawing
 
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.