Constant torque propeller mechanism
AssigneeAuburn University
InventorsChristoph Burger, Roy Hartfield
Life of this patent
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Abstract
A constant torque propeller mechanism allows a propeller to operate very efficiently in both takeoff and cruise flight conditions, which significantly improves aircraft performance. The constant torque propeller mechanism introduces a lightweight and passive propeller control system which requires no electrical power to operate, but at the same time improves the efficiency of the motor propeller combination over the flight envelope.
Claims26
An airplane propeller apparatus comprising:
- a. a housing;
- b. a set of propeller blades coupled to the housing;
- c. a mechanism coupled to the propeller blades configured for affecting propeller pitch;
- and
- d. a spring in communication with the set of propeller blades such that the spring is able to bias the set of propeller blades to a maximum pitch when the set of propeller blades is not moving, further wherein the spring is configured to automatically change the pitch of the set of propeller blades.
An apparatus for changing an airplane propeller blade pitch comprising:
- a. a gear configured for altering propeller pitch;
- b. a motor gear attachment operatively coupled to the gear;
- and
- c. a spring coupled with a motor shaft attachment, the spring configured for affecting the motor gear attachment;
- wherein the spring is configured to position the propeller to a maximum pitch when the propeller blade is not moving, further wherein the spring automatically changes the pitch of the propeller.
A system improving efficiency of operation of an airplane engine comprising:
- a. a housing;
- b. an airplane propeller blade attachment contained within the housing;
- c. a set of beveled gears partially contained within the housing, the set of beveled gears configured for altering propeller pitch by causing the propeller blade attachment to move;
- d. a motor gear attachment operatively coupled to the set of beveled gears;
- e. a motor shaft attachment configured for coupling to a motor shaft;
- f. a spring coupled with the motor shaft attachment, the spring configured for affecting the motor gear attachment;
- and
- g. one or more propeller blades coupled to the blade attachment through a propeller hub attachment;
- wherein the spring is configured to position the one or more propeller blades to a maximum pitch when the propeller is not moving, further wherein the spring automatically changes the pitch of the one or more propeller blades.
A method of improving efficiency of operation of an airplane engine comprising:
- a. biasing airplane propeller blades to a maximum pitch when at rest with a constant torque spring;
- b. reducing the pitch to maintain a constant motor torque;
- and
- c. automatically changing the pitch with the constant torque spring when flight velocity changes, wherein blade loading is proportional to engine torque.
Dependencies are inferred from the claim text.