Cylinder (technology)

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Cylinder is a term used in technology , especially in mechanical engineering , for various machine elements or assemblies . The common feature is the design, at least approximately in the form of a (circular) cylinder , often designed as a hollow cylinder.

Use of the term

Cylinder liner of an opposed piston engine
A hydraulic cylinder on a construction machine


  • a rotating part of machines, with which pressure is exerted on a workpiece or which gives the workpiece properties by changing its direction (e.g. in a calender or the rotary cylinder of a printing machine ), also known as a roller.
  • the working element of a technical circuit, which is controlled by an actuator (often a valve ).

With motors or pumps

In piston steam engines, the steam usually acts alternately on both sides of the piston, and the cylinder is closed on both sides. The steam supply is usually controlled via slides, but sometimes via valves.
In counter-rotating engines , the cylinder liner is open on both sides. The working medium (gas or air, gasoline-air mixture, air for direct injection) is controlled via the inlet and outlet slots.

In linear technology

  • electromechanical cylinders, which are also known as electromechanical lifting cylinders or electromechanical actuators . The basic principle of electromechanical lifting cylinders can also be found in so-called telescopic lifting columns (also: lifting columns or telescopic drives).

Also, gas springs have a cylinder filled with gas filled, that caused by its pressure the extension (the forward stroke) of the gas cylinder piston.

In fluid technology

  • a drive unit for linear - rarely also rotating - movements. The movement of the piston is transmitted to the parts to be moved via the piston rod or magnetic frictional connection. The lead out of the piston rod from the pressure chamber must be sealed. A distinction must be made between single-acting and double-acting cylinders ( work is only done in one direction or in both directions). Cylinders in hydraulics or pneumatics are the two fluid elements

Circuit symbols for cylinders for use in pneumatic or hydraulic circuit diagrams can be found in the list of circuit symbols (fluid technology) .

In printing technology