This series hydraulic cylinder has a compact structure, reliable performance, simple installation, convenient maintenance, with the buffer device and installation diversity and other characteristics, suitable for all kinds of engineering machinery, overweight, transport machinery and engineering vehicles in hydraulic transmission system. The working principle. HSG series double acting single rod piston hydraulic cylinder is the oil pressure to push the piston rod is used as the positive and negative two direction of motion, thus promote the work area of the other reciprocating linear motion