Energy recovering hydraulic cylinder for e.g. excavator, has cylinder tube partly formed in double-structure and with intermediate region serving as gas remaining storage chamber staying in fluid-transmissive connection with stroke chamber

摘要

The cylinder (1) has an annular return stroke chamber placed at a side of a hollow piston rod (6), an oil-supplied return stroke chamber (7) placed at a machine-side and a gas-filled forward stroke chamber (8) placed on a piston-side. A cylinder tube (25) of the cylinder is partly formed in a double-tube structure (3). An intermediate region of the cylinder tube serves as a gas remaining storage chamber (12), which stays in fluid-transmissive connection with the forward stroke chamber. An outer pipe (4) and a piston rod-guiding inner pipe (5) are held by fluid-transmissive spacers.