ELECTROHYDROSTATIC ACTUATOR AND METHOD FOR CONTROLING AND DAMPING A HYDRAULIC ACTUATOR

摘要

An electro-hydrostatic actuator is provided comprising a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator, the pump comprising an inlet and outlet for the hydraulic fluid and an active flow path configured such that In an active operating mode, when the pump is driven by the electric motor, the hydraulic fluid is actively sucked in the inlet and expelled through the outlet. The pump further comprises a bypass flow path configured to open between the inlet and outlet such that, in a damping operating mode, when the pump is not driven by the electric motor, the hydraulic fluid will be able to pass through. pump along the secondary flow path between the inlet and outlet. The hydraulic pump is a rotary piston pump comprising a pump drum driven to rotate by a motor shaft. The bypass flow path comprises one or more bypass holes in a bypass orifice plate that is positioned at the base of the pump drum and driven to rotate by the motor shaft. in damping operating mode, the pump drum and bypass orifice plate are configured to axially separate to form the bypass flow path through a gap between the pump drum and bypass orifice plate created by separating the pump drum and bypass orifice plate.