US 12,146,478 B2
Dual pump fuel systems
Morgan O′Rorke, West Hartford, CT (US); Ryan Susca, Windsor, CT (US); and Ryan Shook, Rockford, IL (US)
Assigned to Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on May 26, 2022, as Appl. No. 17/825,859.
Prior Publication US 2023/0383736 A1, Nov. 30, 2023
Int. Cl. F04B 23/04 (2006.01); F04B 49/22 (2006.01); F23R 3/28 (2006.01); F02C 7/22 (2006.01)
CPC F04B 23/04 (2013.01) [F04B 49/225 (2013.01); F02C 7/22 (2013.01); F23R 3/28 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A fuel pump system comprising:
a main fuel pump between a system fuel inlet and a system fuel outlet;
a main fuel flow path defined between the main fuel pump and the system fuel outlet;
a support fuel pump between the system fuel inlet and the system fuel outlet;
a pressure regulating valve (PRV) comprising:
a PRV inlet in fluid communication with the main fuel flow path;
a PRV outlet in fluid communication with the system fuel inlet;
a PRV first control chamber on a side of a PRV spool and in fluid communication with the main fuel flow path and upstream of the PRV inlet; and
a PRV second control chamber on an opposite side of the PRV spool from the PRV first control chamber;
an electro-hydraulic servo valve (EHSV) comprising:
a first port in fluid communication with the system fuel inlet;
a second port in fluid communication with the system fuel outlet; and
a control port in fluid communication with the PRV second control chamber;
a valve assembly in fluid communication with the support fuel pump fluidically connecting the support fuel pump to the system fuel outlet and comprising:
a pressure bypass valve (PBV) comprising:
a PBV inlet in fluid communication with the support fuel pump;
a PBV outlet in fluid communication with the PBV inlet and the PRV inlet, and downstream of the PRV first control chamber;
a first PBV control chamber on a side of a PBV spool and in fluid communication with the support fuel pump, and
a second PBV control chamber in fluid communication with the system inlet and on an opposite side of the PBV spool from the first PBV control chamber.