Abstract: A split torque gearbox having multiple input shafts. Each input shaft is connected to two face gears. Each face gear is connected to two quill shafts, one is coaxially mounted and the second is not coaxially mounted. Of the two quill shafts, one is positioned on a first side of an output stage and a second quill shaft is located on a second side of the output stage and the quill shafts are connected thereto. The output stage is connected to a main shaft.

Abstract: One embodiment of a coaxial transmission/center hub subassembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a single stage transmission, a transmission housing, and a center hub support structure that are structurally and functionally interactive. The transmission housing includes upper and lower standpipe housings secured in combination with a middle housing. The single stage transmission includes an input pinion gear rotatably mounted in combination with the middle housing, and upper and lower spiral bevel gears rotatably coupled in combination with the input pinion gear to provide counter-rotation thereof. The spiral bevel gears include integral rotor shafts, respectively, rotatably mounted in the standpipe housings.

Abstract: An integrated spline/cone seat subassembly for a rotor assembly that is design optimized to minimize the radial dimensions of the rotor shafts, the rotor shaft bearings, the transmission housing, and the swashplate subassemblies thereof. The integrated subassembly includes a rotor hub having a shaft aperture with a plurality of hub splines extend radially inwardly therefrom. The lower portion of each hub spline has an outwardly tapered portion that makes a predetermined angle with respect to the hub centerline. The integrated subassembly further includes a rotor shaft having a primary shaft portion of a first diameter, an end shaft portion having an intermediate second diameter less than the first diameter, and a conic transition portion that makes a predetermined angle with respect to the rotor shaft axis. The end shaft portion has a plurality of shaft splines extending radially outwardly therefrom that defines a third diameter that is equal to the first diameter.

Abstract: A drive train assembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a sprag clutch, an engine coupling subassembly, a transmission coupling subassembly, and a drive shaft mechanically interconnected at the ends thereof to the engine and transmission coupling subassemblies, respectively. The drive train assembly is design optimized to maximize the functional capability of the sprag clutch, the engine coupling subassembly including an external crown spline coupling, internal spline coupling combination that is mounted in combination with the sprag clutch so that loads transmitted through the external crown spline coupling react through the center of the sprag clutch.

Abstract: A progressive clutch includes a centrifugal clutch 10 attached to a drive shaft and inserted into a clutch housing assembly 16 to engage with clutch material 28 during low rpm operation. As the rpm of the input drive shaft 2 increases, the centrifugal force on pellets 32 overcomes the force of compression springs 34, and extension springs 40 pull a pin engagement assembly 30 towards the clutch housing assembly 16 thus engaging pins 38 into elongated holes 42 to provide positive drive from the drive shaft 2 to the driven shaft 21.