Patent ID: 8997626
Filing Date: 2015-04-07
Classification: F15B,F16K

Abstract:
1. An electro-hydraulic actuator having: a hydraulic pump; an electric motor operatively connected to the hydraulic pump and operable for driving the pump; an actuator moveable in response to fluid flow from the pump, the actuator including a piston movable in a cylinder and defining a piston side chamber and a rod side chamber; a housing for the pump, electric motor and actuator and including a reservoir, the housing including fluid conduits for connecting the reservoir, the pump and the piston side and rod side chambers of the actuator; and a valve actuatable from a closed position to an open position for fluidly connecting both the piston side chamber and the rod side chamber to the reservoir, the valve further including a pressure relief portion that is operable when the valve is in the closed position for relieving pressure from at least one of the piston side chamber or the rod side chamber; and wherein the valve includes an outer body in which the pressure relief portion is located; wherein the outer body includes a plurality of annular grooves formed thereon, each groove having an annular seal positioned therein; and wherein at least one radial bleed hole is provided through the outer body at at least one of the grooves, the one radial bleed hole providing limited pressure relief when the valve is being moved to the open position to prevent the respective seal from being removed by pressure from the respective groove.