We know that the hydraulic cylinders produces a linear motion. It consists of a cylindrical cylinder and a piston rod that moves in and out of the cylinder. The range of motion of the piston is limited by the length of the cylinder. The piston seal divides the cylinder into two chambers: a rod chamber and a rodless chamber. If the oil is filled in the rodless chamber, the piston rod will stick out. When the rod chamber is filled with oil, the piston rod will retract.