Piston hydraulic cylinder can be divided into single-rod and double-rod structure, its fixed by the cylinder block fixed and piston rod fixed in two ways, according to the action of hydraulic pressure has a single-acting type and double-acting type.
In the single-acting hydraulic cylinder, the pressure oil is only provided for one chamber of the cylinder, and the cylinder moves in one direction by hydraulic pressure, while the reverse movement is realized by external force (such as spring force, self-weight or external load, etc.) The two-way motion of piston of double-acting hydraulic cylinder is accomplished by the action of hydraulic pressure through the oil feeding into the two chambers alternately.
A single rod and a double-acting piston hydraulic cylinder is provided with a piston rod only on one side of the piston, thus the effective action area of the two cavities is different. When the oil supply is the same, the speed of the piston is different when the oil is fed into different cavities, and when the load force to be overcome is the same, the oil supply pressure is different when the oil is fed into different cavities, or when the system pressure is adjusted, the hydraulic cylinder can overcome different load forces in two directions.