CONTROL DEVICE FOR FLUID ENERGY TRANSLATORS

A control device for varying the displacement of variable volume fluid energy devices is disclosed. The control cylinder of the present invention is usable with variable volume pumps and motors having a control rod projecting from the pump housing and angular movement of the control rod varies the pump or motor displacement. The control cylinder includes a bore formed in the cylinder, a spool movable within the bore, a lever fixedly attached to the control rod for rotation therewith, a directional control valve manifold mounted to the cylinder for selectively moving the spool within the bore, and a scotch yoke for interconnecting the lever to the spool so that movement of the spool produces an angular movement of the control rod varying the pump displacement. The control device may also be directly applied to an apparatus requiring a linear input for control. A plurality of control devices may be combined to produce an analog input that is either angular or linear.