Patent ID: 9441644
Filing Date: 2016-09-13
CPC Classification: F15B

Claim Text:
1. A linear actuation system comprising: two or more double-acting hydraulic cylinders with each hydraulic cylinder having a cylinder barrel, a cap end wall and a rod end wall that define an interior volume, the barrel surrounds a piston that partitions the interior volume into an extension chamber and a retraction chamber, the piston transfers a force to a load or absorbs a force from an external load; a low pressure valve fluidly coupling each extension chamber and retraction chamber to a low pressure reservoir; a high pressure valve fluidly coupling each extension chamber and retraction chamber to a high pressure accumulator; and wherein, when the system is configured in an energy consuming mode and the load force is in an opposite direction as an extending piston force, the high pressure valve fluidly coupling the extension chamber of an active cylinder to the high pressure accumulator and the low pressure valve fluidly coupling the retraction chamber of the active cylinder to the low pressure reservoir are configured in an open position, and the high pressure valve fluidly coupling the extension and retraction chambers of a passive cylinder to the high pressure accumulator are configured in a closed position and the low pressure valve fluidly coupling the extension and retraction chambers of the passive cylinder to the low pressure reservoir are configured in an open position, and when the system is configured in an energy consuming mode and the load force is in an opposite direction as a retracting piston force, the high pressure valve fluidly coupling the retraction chamber of an active cylinder to the high pressure accumulator and the low pressure valve fluidly coupling the extension chamber of the active cylinder to the low pressure reservoir are configured in an open position, and the high pressure valve fluidly coupling the extension and retraction chambers of a passive cylinder to the high pressure accumulator are configured in a closed position and the low pressure valve fluidly coupling the extension and retraction chambers of the passive cylinder to the low pressure reservoir are configured in an open position, and when the system is configured in an energy recovery mode and the load force is in the same direction as an extending piston, the high pressure valve fluidly coupling the retraction chamber of an active cylinder to the high pressure accumulator and the low pressure valve fluidly coupling the extension chamber of the active cylinder to the low pressure reservoir are configured in an open position, and the high pressure valve fluidly coupling the extension and retraction chambers of a passive cylinder to the high pressure accumulator are configured in a closed position and the low pressure valve fluidly coupling the extension and retraction chambers of the passive cylinder to the low pressure reservoir are configured in an open position, and when the system is configured in an energy recovery mode and the load force is in the same direction as a retracting piston, the high pressure valve fluidly coupling the extension chamber of an active cylinder to the high pressure accumulator and the low pressure valve fluidly coupling the retraction chamber of the active cylinder to the low pressure reservoir are configured in an open position, and the high pressure valve fluidly coupling the extension and retraction chambers of a passive cylinder to the high pressure accumulator are configured in a closed position and the low pressure valve fluidly coupling the extension and retraction chambers of the passive cylinder to the low pressure reservoir are configured in an open position.