Patent attributes
A hydraulic propulsion system is disclosed which includes an input interface configured to receive mechanical power from a power source, a pressure source comprising one or more fixed or variable displacement pumps coupled to the input interface and adaptable to convert mechanical power to hydraulic power and controlling outlet pressure of the pressure source (system pressure), one or more variable displacement motors coupled to the pressure source via a corresponding high-pressure line configured to be mechanically coupled to one or more aerodynamic rotors of an aircraft and comprising a closed loop speed control arrangement in response to a commanded rotor speed, and a controller configured to control the speed of one or more variable displacement motors by providing a control signal for controlling the system pressure.
