| 摘要 |
1,232,232. Stabilizing convertiplane rotor systems. TEXTRON Inc. 8 May, 1968 [9 May, 1967], No. 21705/68. Heading B7W. A convertiplane rotor comprises a main mast 37 rotably mounted at one end on the airframe and having pivotally connected to its other end a stub mast 42 carrying the rotor blades 41, and cyclical variable pitch linkages 53, 54, 56 connected from pitch horns 58 of each rotor to a swashplate 40 operable when the stub mast pivots with respect to the main mast to vary the pitch of the blades to oppose the instability produced by that angular displacement, the rotation of the joints between the pitch horns and links defining a control plane rearward of the pivotal connection between the main and stub masts. The stub mast 42 is a tapered hollow body pivotally connected to the main mast 37 at its reduced diameter through splines 46, 44. Its large diameter end is inward and carries a hub 61 on which the rotors 41 are mounted. The stub mast is driven at the same speed as the main mast but drives the hub 61 at a reduced speed through sun and planet gears 63, 64. A central control tube 48 extends through and beyond the end of main mast 37 and carries a rotatably mounted collective head on which are pivotally mounted walking beams 53 (one to each blade 41). One end of beam 53 is connected to a blade pitch horn 58 and the other end to a swash plate 40. Thus angular displacement between stub mast and main mast will cause a similar displacement between swash plate 40 and plane of rotation of pitch horns 58 with a consequential change in pitch of the rotor blades. In an alternative embodiment (Fig. 4) a rotor hub 79 is driven by a gimbal 82 and pillow block housing 84. The housing 84 which forms the stub mast is rotatably connected to a main mast 83 through a universal joint 92. Pivotal movement is provided between stub mast and main mast by the universal joint 92. This comprises an inner bowl 93 connected to the main mast movable over a seating ring 103 on an outer bowl 99 connected to the stub mast. Cyclical pitch change of the rotor blades is effected through a swash plate 106, tube 107, walking beams 108, 114 and tube 116. The change in pitch produces forces opposite to those which caused the angular displacement between stub mast and main mast. |
