Propeller governor for electric synchronous thrust
AssigneeEmbraer S.A.
InventorIerko de Magalhães Gomes
Life of this patent
Estimating the term…
Abstract
A thrust propeller variable pitch actuator is controlled by a governor that uses propeller pitch as a variable to increase or decrease torque—not to maintain the propeller speed or RPM but instead to maintain certain established electric current supplied to rotate the thrust propeller.
Claims16
An aircraft control system for use with a variable pitch propeller rotated by an electric motor supplied by a polyphase supply current, the aircraft control system comprising:
- an actuator that controls the variable pitch of the propeller;
- an electric circuit coupled to sense the current drawn by the electric motor and to control the pitch actuator in response to the sensed current drawn in order to vary the torque the electric motor applies to rotate the variable pitch propeller and thereby maintain the current at a set point without requiring maintenance of propeller rotation speed;
- and
- an alternator connected to a thermal engine such as a gas turbine engine, the alternator configured to generate the polyphase supply current and to supply the polyphase supply current to the electric motor,
- wherein the alternator is connected to the thermal engine through a gearbox, and the alternator produces an alternating current frequency that is dependent on the rotational speed of an output shaft of the gearbox, the gearbox output shaft rotational speed determining speed at which the electric motor rotates and thus the speed at which the propeller rotates.
A control method for operating an aircraft of the type having a variable pitch propeller coupled to an electric motor supplied by a polyphase supply current, the control method comprising:
- rotating an alternator with a thermal engine;
- producing a polyphase alternating current with the alternator;
- the alternator supplying the polyphase alternating current as the polyphase supply current to the electric motor;
- sensing the supply current;
- and
- hydraulically controlling the variable pitch of the propeller in response to the sensed supply current to maintain the sensed supply current at a set point without maintaining propeller rotation speed,
- wherein the alternator is connected to the thermal engine through a gearbox, and the alternating current the alternator produces has a frequency that is dependent on rotational speed of an output shaft of the gearbox, the gearbox output shaft rotational speed determining speed at which the electric motor rotates and thus the speed at which the propeller rotates.
An aircraft comprising:
- an alternator connected to a thermal engine such as a gas turbine engine, the alternator configured to generate a polyphase supply current and to supply the polyphase supply current to a synchronous electric motor;
- a variable pitch propeller rotated by the synchronous electric motor;
- a pitch actuator configured to control the variable pitch of the propeller;
- a current sensor connected to sense polyphase current drawn by the synchronous electric motor;
- and
- a controller operatively coupled to the current sensor and configured to control the pitch actuator in response to the sensed polyphase current drawn without requiring maintenance of propeller rotation speed,
- wherein the alternator is connected to the thermal engine through a gearbox, and the alternator produces an alternating current frequency that is dependent on the rotational speed of an output shaft of the gearbox, the gearbox output shaft rotational speed determining speed at which the synchronous motor rotates and thus the speed at which the propeller rotates.
Dependencies are inferred from the claim text.