Below is a list of Hydraulic Cylinders manufacturers from Rockford, Illinois. Hydraulic cylinders are actuation devices that convert the hydraulic energy of pressurized fluids into the mechanical energy needed to control the movements of machine linkages and attachments. This energy conversion generates linear force and motion. While single acting cylinders are available, most are double acting hydraulic cylinders, meaning that they can move in both directions along a horizontal, vertical or any other predetermined plane.