Patent ID: 6974115
Filing Date: 2005-12-13
Classification: F01C,F04C,F16K

Abstract:
1. An electro-hydrostatic linear actuator that includes: a sealed housing mounted upon a base, said housing containing a reservoir for filling the interior of the housing with a dielectric fluid; a motor having a rotor shaft that is connected to a pump; said motor and said pump being immersed in said fluid reservoir so that said pump can draw fluid from said reservoir; a hydraulic cylinder located outside of said housing that contains a piston attached to a piston rod that passes out of said cylinder, said piston dividing the cylinder in a first chamber and a second chamber; means for biasing said piston rod into a home position; a supply line for connecting the pump outlet to one of said chambers; and a controller immersed in said fluid that contains circuitry for controlling said motor such that the pump raises the fluid pressure in said one chamber to move the piston rod to a selected operative position.