Automatic pitch change rotary wing rotor system and method of rotor control

Abstract

A helicopter main rotor control system includes a trunnion head mountable to a rotatable helicopter mast wherein the trunnion head has a control bar pivot supported by the trunnion head and pivotal about an axis substantially at a right angle to the helicopter mast. A control bar extends through the control bar pivot at a right angle thereto, and a pair of opposing leaf hinges are pivotal about the control bar and centered about said trunnion head. Each leaf hinge has a hinge plate extending from the control bar and defines a rotor blade mount hole therethrough.

We/I claim: 
     
         1 . A helicopter main rotor control system comprising:
 a trunnion head mountable to a rotatable helicopter mast, said trunnion head including a control bar pivot supported by said trunnion head and pivotal about an axis substantially at a right angle to said helicopter mast;   a control bar extending through said control bar pivot at a right angle thereto; and   a pair of opposing leaf hinges pivotal about said control bar and centered about said trunnion head, each said leaf hinge having a hinge plate extending from said control bar and defining a rotor blade mount hole therethrough.   
     
     
         2 . The helicopter main rotor control system according to  claim 1  further including a rotor blade affixed to each said hinge plate at said rotor blade mount hole and pivotal thereabout. 
     
     
         3 . The helicopter main rotor control system according to  claim 2  wherein said rotor blades are pivotal through an arc of zero degrees to ninety degrees with respect to said control bar. 
     
     
         4 . The helicopter main rotor control system according to  claim 2  wherein said rotor blades are pivotal through an arc of fifteen to forty-five degrees with respect to said control bar. 
     
     
         5 . The helicopter main rotor control system according to  claim 2  wherein said rotor blades are pivotal through an arc of twenty five to thirty degrees with respect to said control bar. 
     
     
         6 . The helicopter main rotor control system according to  claim 2  wherein each said rotor blade includes a high lift airfoil cross-section. 
     
     
         7 . The helicopter main rotor control system according to  claim 2  wherein a pitch angle of attack of each said rotor blade is fixed and non-rotatable with respect to a plane of said leaf hinge when said rotor is affixed at a ninety degree angle with respect to said control bar. 
     
     
         8 . The helicopter main rotor control system according to  claim 7  wherein each said rotor blade is mounted a fixed distance above said hinge plate. 
     
     
         9 . The helicopter main rotor control system according to  claim 7  wherein each said rotor blade mounting includes a hydraulic apparatus for adjusting a distance each said rotor blade is above said hinge plate. 
     
     
         10 . The helicopter main rotor control system according to  claim 7  wherein each said rotor blade mounting includes a ball screw apparatus for adjusting a distance each said rotor blade is above said hinge plate. 
     
     
         11 . The helicopter main rotor control system according to  claim 1  wherein said control bar terminates at two distal ends thereof and further includes a weight affixed at each said end of said control bar. 
     
     
         12 . A helicopter rotor control system comprising:
 a trunnion head mountable to a rotatable helicopter mast, said trunnion head including a control bar pivot supported by said trunnion head and pivotal about an axis substantially at a right angle to said helicopter mast;   a control bar extending through said control bar pivot at a right angle thereto;   a pair of opposing leaf hinges pivotal about said control bar and centered about said trunnion head, each said leaf hinge having a hinge plate extending from said control bar and defining a rotor blade mount hole therethrough; and   a rotor tilting mechanism for directional control.   
     
     
         13 . The helicopter control system according to  claim 12  wherein said rotor tilting mechanism for directional control comprises a swash plate including control rods running to a yoke encircling said trunnion head and said mast. 
     
     
         14 . The helicopter control system according to  claim 12  wherein said rotor tilting mechanism for directional control comprises a mast tilting mechanism. 
     
     
         15 . The helicopter control system according to  claim 12  further including a rotor blade affixed to each said hinge plate at said rotor blade mount hole and pivotal thereabout. 
     
     
         16 . The helicopter main rotor control system according to  claim 15  wherein a pitch angle of attack of each said rotor blade is fixed and non-rotatable with respect to a plane of said leaf hinge when said rotor is affixed at a ninety degree angle with respect to said control bar. 
     
     
         17 . The helicopter main rotor control system according to  claim 16  wherein each said rotor blade is mounted a fixed distance above said hinge plate. 
     
     
         18 . The helicopter main rotor control system according to  claim 16  wherein each said rotor blade mounting includes a hydraulic apparatus for adjusting a distance each said rotor blade is above said hinge plate. 
     
     
         19 . The helicopter main rotor control system according to  claim 16  wherein each said rotor blade mounting includes a ball screw apparatus for adjusting a distance each said rotor blade is above said hinge plate. 
     
     
         20 . The helicopter main rotor control system according to  claim 12  wherein said control bar terminates at two distal ends thereof and further includes a weight affixed at each said end of said control bar.