Patent ID: 8857168

Claim:
A hydraulic system comprising: an actuator having a piston disposed within a cylinder, and a rod extending from the piston and extending out of the cylinder, the piston defining a rod chamber and a cap side chamber within the cylinder, a pump adapted to operate as a pump or as a motor, the pump being adapted to selectively provide varied flow rates, the pump being adapted to selectively deliver pressurized hydraulic fluid to and receive pressurized hydraulic fluid from the chambers of the actuator, movement of the piston relative to the cylinder being dependent upon the selectively varied flow rates, a rod side fluid connection between the pump and the rod chamber, a cap side fluid connection between the pump and the cap side chamber, at least one selectively actuatable regeneration valve disposed to selectively provide flow from the cap side fluid connection to the rod side fluid connection, and a controller that controls the selectively varied flow rate of the pump in response to a commanded motion and relative positions of the piston and cylinder, the controller being configured to cause the actuation of the regeneration valve during a retraction of the piston into the cylinder when the pump is acting as a motor.