The Parts Of A Hydraulic Cylinder

Update:Sep 30, 2019

Understanding the various pieces that make up a hydraul […]

Understanding the various pieces that make up a hydraulic cylinder can help us to understand the construction.



The piston is one of the most important pieces of a hydraulic cylinder. The piston has the core function of the device, which is separate the two sides of pressure that become created in the barrel. This causes the extension and contraction of the cylinder itself.

The piston attaches to the piston rod by a series of bolts, nuts, and threads. These are all placed in a fashion that allows for the transfer of linear motion.

The piston rod is a connector that works between the hydraulic actuator and the machine thread or mounting attachment. The piston rod is a piece of steel that extends from the cylinder to the rod-end head.



The cylinder barrel itself is in place to ensure that the created pressure of the machine stays contained within the chamber. To do this, the inner portion of the barrel is ground down to an incredibly slim 4/16ths of an inch. This fine surface allows the piston to make free movement through the chamber as it moves up and down.

The cylinder head is then attached to the body by a similar series of bolts and threading. The head encloses the pressure into the cylinder with the assistance of various sealers.



There a wide variety of seals, and which kind will be used on a particular seal will depend on the conditions and circumstances at hand. Factors such as cylinder speed, climate, working pressure, and so forth will determine what kind of seal needs to be used during construction of a cylinder.

Piston seals can be single acting or double acting depending on what is needed. Most seals are made from rubber and offer some elastomeric properties, though these sometimes don’t hold up to incredibly high temperatures.

For hydraulic cylinders that will be used in high temperatures, metallic seals made from cast iron are often used.

The cylinder cap ensures that pressure is kept in the chamber when the piston moves in and out. It also serves to help with cylinder mounting.