What are Hydraulic Cylinders?

Hydraulic cylinders play a large role in most industries. They are used in many daily mechanical devices, including in construction equipment (engineering vehicles), manufacturing machinery, and civil engineering.

The hydraulic pressure in these cylinders is in the form of hydraulic fuels that are stored under pressure in these cylinders. The energy stored in these oils is converted into motion. In a complete hydraulic system, a hydraulic motor consists of one or more hydraulic cylinders. A pump regulates the oil-flow in the hydraulic system. The pump is a part of the generator of a hydraulic system. The hydraulic cylinders initiate the pressure of the oil, which cannot be more than that required by the load.

A hydraulic cylinder consists of a cylinder barrel, piston, and a piston rod.

Cylinder barrel

The main function of the cylinder body is to hold cylinder pressure. The cylinder barrel is mostly made from a seamless tube. The cylinder barrel is ground and/or honed internally with a typical surface finish of 4 to 16 micro inch. The piston reciprocates in the cylinder.

Piston

The main function of the piston is to separate the pressure zones inside the barrel. The piston is machined with grooves to fit Elastoplast or metal seals and bearing elements. These seals can be single acting or double acting. The difference in pressure between the two sides of the piston causes the cylinder to extend and retract. The piston is attached with the piston rod by means of threads, bolts, or nuts to transfer the linear motion.

Piston rod

The piston rod is typically a hard chrome-plated piece of cold-rolled steel which attaches to the piston and extends from the cylinder through the rod-end head. In double rod-end cylinders, the actuator has a rod extending from both sides of the piston and out both ends of the barrel. The piston rod connects the hydraulic actuator to the machine component doing the work. This connection can be in the form of a machine thread or a mounting attachment. The piston rod is highly ground and polished so as to provide a reliable seal and prevent leakage.