What is a hydraulic cylinder?
Through this page, I tried to make a short description about hydraulic cylinder although the subject is well known. If google it sure it will be found some good information about it.
Even though the subject is widely know I will show more deeply information from sources, where I learned and understand this topic.
Cylinders can be consider like hydraulic motors because they perform work. As motor, a cylinder converts hydraulic energy into mechanical energy.
Hydraulic cylinder or rams convert hydraulic working energy into straight line or linear mechanical motion.
The force which can be exerted by a cylinder depends upon the area of the piston and the oil pressure which is delivered to the cylinder. At the same pressure a cylinder with a larger piston surface area will deliver more force than one with a smaller area. If the pressure of the oil in the cylinder is increased, the force exerted by piston also increases.
Cylinder can be divided into two types: single acting cylinder and the double acting cylinder.
Single acting hydraulic cylinder have a robust body or cylinder barrel (1), an enclosure at each end(2) and a movable piston(3) attached to a piston rod(4). At one end(5) there is an inlet port by which oil enters, and at the other end there is a vent port(6) to allow air to escape when the piston moves.
The RAM is usually robust with a large diameter piston rod. This retracts to its original position via an external load.
In addition, there is single acting cylinder, which retracts via spring. These springs are found in a small cylinder, because of their limited strength.
Double acting hydraulic cylinder have a robust body or cylinder barrel and an enclosure at each end namely : cap end and head or rod end. Inside is a movable piston attached to a piston rod.
At the both ends there is an inlet/outlet port to allow fluid to circulate – going in an out.
The extend stroke of a double acting cylinder will always be able to exert a bigger force than the retraction stroke. The area of the retraction stroke is smaller than the area of the extend stroke due to the piston rod area.
Therefore, a cylinder which has a cap end area twice as larger as of the head or rod end area will have double force during extension than on retraction at the same pressure.