초록 ▼

A control and actuating system for adjusting the cyclic pitch of the blades of a helicopter automatically and independently in response to the blade gyrating angular position and to the helicopter forward velocity. This action is also independent of the control and adjustment of the collective pitch

A control and actuating system for adjusting the cyclic pitch of the blades of a helicopter automatically and independently in response to the blade gyrating angular position and to the helicopter forward velocity. This action is also independent of the control and adjustment of the collective pitch. The actuation of the blade pitch is performed by means of cams and followers. A hydraulic force-amplifying system is used between the follower/cam assemblies and the blade pitch actuator so as to isolate the follower/cam assemblies from the load carrying components of the system. The displacement signals generated by two cams are combined into a single linear displacement signal which causes a corresponding rotational movement of the blade. The axial position of one cam is determined by the pilot\s action and the axial position of the other cam is defined by the helicopter forward speed. The two cams have surfaces that are not of revolution and which remain fixed for a given set combination of pilot\s action and forward speed. The blade cyclic pitch variation is caused by the gyration of a housing to which the blades are attached and which contains and encloses the blade pitch control and actuating system.

대표청구항 ▼

A helicopter blade cyclic pitch control system, said system comprising: a fixed housing for mounting on an airframe; a rotatable housing mounted on said fixed housing for rotating about a substantially vertical axis; a plurality of blades, each having a pitch axis substantially orthogonal to said su

A helicopter blade cyclic pitch control system, said system comprising: a fixed housing for mounting on an airframe; a rotatable housing mounted on said fixed housing for rotating about a substantially vertical axis; a plurality of blades, each having a pitch axis substantially orthogonal to said substantially vertical axis, rotatably mounted at an inner end to said rotatable housing and extending radially outward therefrom for rotation about said pitch axis; a central support shaft mounted within said housings and extending along said substantially vertical axis; cyclic pitch control means comprising an axially moveable radial cam system non-rotatably mounted on said central support shaft from imposing a selective cyclic pitch on said blades as said rotatable housing rotates about said vertical axis; and collective pitch control means comprising an axially movable cam mounted on said support shaft for axial movement thereon, pilot input control means for selectively moving said axially movable cam along said central support shaft, and a push-pull follower positively engaging said cam and operatively connected to said blades for independently imposing a collective pitch on said blades independently of said cyclic pitch control means; whereby the axially moveable radial cam system non-rotatably mounted on the central support shaft includes a two-dimensional cam also non-rotatably mounted on the central support shaft and capable of axial movement thereabout, said axial movement being independently imposed by axially actuating means controlled by the helicopter forward velocity and independent of pilot control, thereby enabling the cyclic pitch control means to superimpose a non-sinusoidal programmed pitch variation on the collective pitch of the blades, said non-sinusoidal pitch variation being determined independently by the position of the blade in its rotation about the vertical axis and by the helicopter forward speed, albeit remaining independent of the collective pitch adjustment onto which said non-sinusoidal variation is superimposed.