| 摘要 |
Disclosed is a novel jump take-off rotorcraft rotor head comprising: (i) two or more rotor blades and/or rotor blade attachment means, wherein said rotor blades and/or said rotor blade attachment means are rotatably attached to rotate about a rotor axis, and pivot through a flapping and/or teetering hinge, and have a pitch angle; (ii) pitch angle changing means for collectively changing said pitch angle; (iii) centrifugal pitch stop mechanism having an activation point and comprising one or more centrifugal plates; and (iv) control means for providing a control input to said pitch angle changing means; wherein said centrifugal pitch stop mechanism is configured to attain an activated state and to interact with said pitch angle changing means; wherein said activated state is attained when the rotational speed of said rotor blades and/or said rotor blade attachment means is greater than said activation point and when a control input is provided by said control means; and wherein said activation point is less than the minimum rotational speed of the rotor blades that is required for flying the rotorcraft. Also disclosed is a method of performing a vertical takeoff and flight manoeuvre in a rotorcraft or autogyro; said method comprising the steps of: 1) providing a control input to set the pitch angle of the rotor blades collectively to a minimised drag collective pitch angle A; 2) prerotating said rotor blades to a speed which is greater than the minimum rotational speed of the rotor blades that is required for flying the rotorcraft or autogyro; 3) providing a control input to increase the pitch angle of said rotor blades collectively to a pitch angle C so as to perform a vertical takeoff manoeuvre; and 4) removing said control input and thereby reducing the pitch angle of said rotor blades collectively to a pitch angle B which is suitable for flying the rotorcraft. |
