For hydraulic cylinders, the following is stated with regard to their operating mode differentiate between differential cylinders and double rod cylinders.




For hydraulic cylinders, a distinction is made between differential cylinders and double rod cylinders based on their methods of operation. Differential cylinders generally have only one piston rod. This means that there are differences in the size of the surfaces that determine the force generated and the speed of the piston. Under the same pressure and flow conditions both the force generation and the speed of the forwards and return stroke of the cylinder are distributed in accordance with the area ratio.

An additional distinction is made between single-acting and double-acting cylinders While single-acting hydraulic cylinders have a pressure port on only one end, double-acting hydraulic cylinders have a port for both cylinder chambers in order to be able to perform forwards and backwards motions. With single-acting hydraulic cylinders, either the forward or return stroke has to be performed by an external force, such as spring force or gravity.




Cylinders with a through style piston rod are called double rod cylinders. Unlike with differential cylinders, the pressurized surface is the same size for both the forwards and return stroke. This means that the work with the same conditions and in the same manner for both the forwards and return stroke. The amount of hydraulic fluid that should be introduced corresponds to the volume being displaced.