The hydraulic cylinder is the hydraulic actuator that transforms the hydraulic energy into mechanical energy and makes a linear reciprocating movement (or swinging motion). It is simple in structure and reliable in work. It is used to realize reciprocating movement, can be removed from the deceleration device, and there is no transmission clearance, smooth movement, so in a variety of mechanical hydraulic system has been widely used. The output force of the hydraulic cylinder is proportional to the effective area of the piston and the pressure difference between the two sides; the hydraulic cylinder is basically composed of cylinder and cylinder head, piston and piston rod, sealing device, buffering device and exhaust device. The cushioning device and the exhaust device depending on the specific application situation, other devices are essential.
The hydraulic cylinder is the actuator of the hydraulic transmission system, it is the energy conversion device which transforms the hydraulic power into mechanical energy. The hydraulic motor realizes the continuous rotary motion, and the hydraulic cylinder realizes the reciprocating motion. Hydraulic cylinder structure type has piston cylinder, plunger cylinder, swing cylinder three categories, piston cylinder and plunger cylinder to achieve reciprocating linear movement, output speed and thrust, swing cylinder to achieve reciprocating swing, output angular speed (rotational speed) and torque. In addition to the use of a single hydraulic cylinder can be two or more combinations or combined with other agencies to use. To accomplish special functions. The hydraulic cylinder is simple in structure and reliable in operation, and has been widely used in the hydraulic system of the machine tool.