US 12,454,945 B2
Partial stroke fluidic pump-motor with high mechanical efficiency
Thomas Richard Chase, Minneapolis, MN (US); Perry Yan-Ho Li, Plymouth, MN (US); and Michael B. Rannow, Eden Prairie, MN (US)
Assigned to REGENTS OF THE UNIVERSITY OF MINNESOTA, Minneapolis, MN (US)
Filed by REGENTS OF THE UNIVERSITY OF MINNESOTA, Minneapolis, MN (US)
Filed on May 2, 2023, as Appl. No. 18/142,104.
Claims priority of provisional application 63/337,720, filed on May 3, 2022.
Prior Publication US 2023/0358217 A1, Nov. 9, 2023
Int. Cl. F04B 1/0531 (2020.01); F04B 1/0413 (2020.01); F04B 1/0452 (2020.01)
CPC F04B 1/0531 (2013.01) [F04B 1/0413 (2013.01); F04B 1/0452 (2013.01)] 21 Claims
OG exemplary drawing
 
1. An apparatus configurable as one or both of a partial stroke pump or a partial stroke motor, comprising:
a piston coupled to a rotating shaft to evacuate a fluid within a cylinder during an upstroke;
a latching check valve in fluid communication with: a low pressure port of the cylinder;
a low pressure supply line at a low pressure; and a latch supply line; and
a rotary valve selectively coupling one of the low pressure supply and a pilot pressure supply of the fluid to the latch supply line over different timing angle ranges of the rotating shaft, the pilot pressure supply having a pressure greater than the low pressure, wherein a pressure change between the low pressure and the pilot pressure applied by the rotary valve to the latch supply line during each pumping upstroke or motoring upstroke of the piston causes the latching check valve to change between a bypass state and a conventional check valve state, wherein, when operating as the partial stroke pump, the bypass state allows the pressure in the cylinder to fall below a high pressure during a first part of each pumping upstroke and the conventional check valve state allows the pressure in the cylinder to rise to the high pressure during a second part of each pumping upstroke, and wherein when operating as the partial stroke motor, the bypass state allows the fluid to be evacuated from the cylinder at a low pressure during a first part of each motoring upstroke and the conventional check valve state allows the pressure in the cylinder to increase during a second part of each motoring upstroke.