公开(公告)号：US20230358217A1

公开(公告)日：2023-11-09

申请号：US18142104

申请日：2023-05-02

Applicant: REGENTS OF THE UNIVERSITY OF MINNESOTA

Inventor： Thomas Richard Chase ,  Perry Yan-Ho Li ,  Michael B. Rannow

IPC: F04B1/0452 ,  F04B1/0413 ,  F04B1/0531

CPC classification number: F04B1/0531 ,  F04B1/0413 ,  F04B1/0452

Abstract: A partial stroke pump or motor includes a piston coupled to a rotating shaft to evacuate a fluid within a cylinder during an upstroke. A latching check valve includes an actuator piston that is displaceable within a center cavity to bypass a blocking member in a bypass state. The actuator piston is driven by a latch supply line. A spool of a rotary valve selectively couples one of the low and pilot pressure supplies to the latch supply line over different timing angle ranges of the rotating shaft. Coupling of the pilot pressure to the latch supply line causes the bypass state. When operating as a pump, the bypass state causes the pressure in the cylinder to fall below the high pressure during part of the upstroke. When operating as a motor, the bypass state allows the fluid to be evacuated from the cylinder during the upstroke.