A system and method for storing potential energy for a material handler. The system and method involves actuating a machine element using hydraulic cylinders; measuring a position of the machine element; controlling the hydraulic cylinders with a hydraulic circuit by an electronic control unit; determining a maximum target pressure for at least one gas actuator coupled to the machine element; calculating a target pressure for the at least one gas actuator at the position; measuring a gas pressure measurement from the at least one gas actuator; comparing the target pressure to the gas pressure measurement; and adjusting a hydraulic adjustment valve to increase or decrease an amount of hydraulic fluid within a hydraulic chamber of an accumulator thereby changing a gas pressure within the at least one gas actuator to correspond to the target pressure.

A system and method for storing potential energy for a material handler. The system and method involves actuating a machine element using hydraulic cylinders; measuring a position of the machine element; controlling the hydraulic cylinders with a hydraulic circuit by an electronic control unit; determining a maximum target pressure for at least one gas actuator coupled to the machine element; calculating a target pressure for the at least one gas actuator at the position; measuring a gas pressure measurement from the at least one gas actuator; comparing the target pressure to the gas pressure measurement; and adjusting a hydraulic adjustment valve to increase or decrease an amount of hydraulic fluid within a hydraulic chamber of an accumulator thereby changing a gas pressure within the at least one gas actuator to correspond to the target pressure.

Venting of gaseous fuel during operation and after shutdown of an internal combustion engine increases emissions. A vent handling apparatus for a gaseous fuel system of an internal combustion engine comprises an accumulator for storing gaseous fuel; a first valve selectively enabling fluid communication between the accumulator and one of a gaseous fuel communication passage and a gaseous fuel storage vessel, the gaseous fuel communication passage delivering gaseous fuel to the internal combustion engine for combustion; and an apparatus for selectively returning the gaseous fuel from the accumulator to the internal combustion engine for combustion.

Venting of gaseous fuel during operation and after shutdown of an internal combustion engine increases emissions. A vent handling apparatus for a gaseous fuel system of an internal combustion engine comprises an accumulator for storing gaseous fuel; a first valve selectively enabling fluid communication between the accumulator and one of a gaseous fuel communication passage and a gaseous fuel storage vessel, the gaseous fuel communication passage delivering gaseous fuel to the internal combustion engine for combustion; and an apparatus for selectively returning the gaseous fuel from the accumulator to the internal combustion engine for combustion.

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

A hydraulic system including an accumulator and a hydraulic transformer is disclosed. The hydraulic transformer includes first and second variable displacement pump/motor units mounted on a rotatable shaft. The rotatable shaft has an end adapted for connection to an external load. The first variable displacement pump/motor unit includes a first side that fluidly connects to a pump and a second side that fluidly connects to a tank. The second variable displacement pump/motor unit includes a first side that fluidly connects to the accumulator and a second side that fluidly connects with the tank.

A hydraulic accumulator including an energy storage apparatus with a first piston face configured to reversibly compress an energy storage medium and a second piston face forming at least part of an inner surface of a corresponding second fluid chamber reversibly expandable by movement of the second piston face. A third piston face forms at least part of an inner surface of a corresponding third fluid chamber reversibly expandable by the third piston face. The first, second and third piston faces are coupled together.

A hydraulic actuator includes an energy recuperation device which harvests the energy generated from the stroking of a shock absorber. The energy recuperation device can function in a passive energy recovery mode for the shock absorber to store recovered energy as fluid pressure or it can be converted to another form of energy such as electrical energy.

A hydraulic actuator includes an energy recuperation device which harvests the energy generated from the stroking of a shock absorber. The energy recuperation device can function in a passive energy recovery mode for the shock absorber to store recovered energy as fluid pressure or it can be converted to another form of energy such as electrical energy.