US 9,809,957 B2
Energy recovery method and system
Marcus Rösth, Boräs (SE)
Assigned to Parker Hannifin AB, Boras (SE)
Appl. No. 14/122,027
Filed by Marcus Rösth, Boräs (SE)
PCT Filed May 23, 2011, PCT No. PCT/SE2011/050641
§ 371(c)(1), (2), (4) Date Jan. 10, 2014,
PCT Pub. No. WO2012/161628, PCT Pub. Date Nov. 29, 2012.
Prior Publication US 2014/0123633 A1, May 8, 2014
Int. Cl. F15B 1/033 (2006.01); E02F 9/22 (2006.01); F15B 21/14 (2006.01); F15B 1/02 (2006.01)
CPC E02F 9/2217 (2013.01) [E02F 9/2296 (2013.01); F15B 1/024 (2013.01); F15B 1/033 (2013.01); F15B 21/14 (2013.01); F15B 2211/20546 (2013.01); F15B 2211/20569 (2013.01); F15B 2211/212 (2013.01); F15B 2211/30575 (2013.01); F15B 2211/31 (2013.01); F15B 2211/327 (2013.01); F15B 2211/6346 (2013.01); F15B 2211/7053 (2013.01); F15B 2211/761 (2013.01); F15B 2211/88 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An energy recovery method for a hydraulic system comprising a hydraulic cylinder, a pump for supplying pressurized fluid to the hydraulic actuator, a tank, a supply conduit, a return conduit, and a hydraulic accumulator that is fluidly connected to said return conduit at an accumulator coupling point, the method comprising the steps of:
charging said hydraulic accumulator,
storing fluid in said hydraulic accumulator,
directing, independently of the pump, fluid from said hydraulic accumulator into an expanding chamber of said hydraulic cylinder during an overrunning load condition, and
controlling the flow of fluid from said hydraulic accumulator into said expanding chamber by an accumulator control valve that is controlled by an electronic control unit,
wherein said step of charging said hydraulic accumulator includes regulating the charging pressure of said hydraulic accumulator by using a counter pressure valve that is controlled by the electronic control unit and arranged at said return conduit between said accumulator coupling point and said tank.