1, the cylinder is to guide the piston in the cylinder for linear reciprocating motion of the cylindrical metal parts. Work in the engine cylinder through the expansion of thermal energy into mechanical energy; gas in the compressor cylinder to accept the piston compression and increase the pressure.
2, turbine, rotary piston engine shell is usually called "cylinder". Cylinder applications: printing (tension control), semiconductor (spot welder, chip grinding), automation control, robotics and so on.