Patent ID: 7444809

Claim:
A hydraulic system, comprising: a tank configured to hold a supply of fluid; a primary source configured to pressurize the fluid and having a suction inlet and a discharge outlet; a first actuator configured to receive pressurized fluid from the discharge outlet of the primary source; an accumulator in fluid communication with the tank, the suction inlet of the primary source, and the first actuator; a first valve mechanism disposed between the suction inlet of the primary source and the accumulator, wherein the valve mechanism is movable between a first position at which fluid returning from the first actuator is directed to the suction inlet of the primary source, and a second position at which fluid returning from the first actuator is directed to only the accumulator; an energy recovery device in fluid communication with the first actuator, the accumulator, and the primary source; a second valve mechanism disposed between the energy recovery device and the accumulator and first actuator; and a third valve mechanism disposed between the suction inlet of the primary source and the energy recovery device, wherein the accumulator is selectively fluidly communicated with the suction inlet of the primary source at a location between the third valve mechanism and the suction inlet of the primary source.