US 12,454,950 B2
Direct control for variable displacement pumps using a bypass valve and a minimum pressure shutoff valve
Ryan Prescott Susca, Windsor, CT (US); and Ryan Shook, Loves Park, IL (US)
Assigned to Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Jan. 13, 2023, as Appl. No. 18/096,971.
Prior Publication US 2024/0240631 A1, Jul. 18, 2024
Int. Cl. F04B 49/24 (2006.01); F04B 49/00 (2006.01)
CPC F04B 49/24 (2013.01) [F04B 49/002 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line, wherein the VDP includes a variable displacement mechanism configured to vary pressure to the outlet line;
a bypass valve (BPV) including a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP;
a minimum pressure shutoff valve (MPSOV) connected in fluid communication with the outlet line, configured to block flow through the outlet line for shutoff, wherein the MPSOV is connected in fluid communication with the BPV for triggering recirculation through the BPV;
an actuator operatively connected to control the BPV to vary flow from the BPV inlet to the bypass line;
a flow sensing valve (FSV) connected in the outlet line, wherein the FSV includes a sensor configured to generate sensor data indicative of flow out of the outlet line; and
a controller operatively connected to the actuator to control recirculation flow passed through the BPV based on the sensor data and based on a predetermined low threshold of flow through the VDP.