Abstract:
An integrated spline/cone seat subassembly (190) for an unmanned aerial vehicle (10) having a rotor assembly (100) that includes ducted, counter-rotating rotors (200, 202), comprising:a rotor shaft (128R or 130R) having an axis, said rotor shaft (128R or 130R) includinga primary shaft portion (192) having a first diameter (D 1 ),an end shaft portion (194) having a second diameter (D 2 ) and having a plurality of shaft splines (198) extending radially outwardly therefrom, anda conic transition portion (196) intermediate said primary and end shaft portions (192, 194), said conic transition portion (196) making a predetermined angle (β) with respect to said axis of said rotor shaft (128R or 130R); anda rotor hub (204) having a centerline (212), said rotor hub (204) having a shaft aperture (206) having a plurality of hub splines (208) extending radially inwardly therefrom;said plurality of hub splines (208) and said plurality of shaft splines (198) being interleaved in combination to provide a rotational interlock between said rotor hub (204) and said rotor shaft (128R or 130R) in the rotor assembly (100); characterized in thateach of said hub splines (208) having an outwardly tapered lower portion (210) that makes a predetermined angle (θ) with respect to said centerline (212); andsaid predetermined angle (θ) of said outwardly tapered lower portions (210) of said hub splines (208) being equal to said predetermined angle (β) of said conic transition portion (196) of said rotor shaft (128R or 130R) wherein said tapered lower portions (210) of said hub splines (208) abuttingly engage and are mechanically supported by said conic transition portion (196) of said rotor shaft (128R or 130R) in the rotor assembly (100).
Abstract:
An integrated spline/cone seat subassembly (190) for an unmanned aerial vehicle (10) having a rotor assembly (100) that includes ducted, counter-rotating rotors (200, 202), comprising:a rotor shaft (128R or 130R) having an axis, said rotor shaft (128R or 130R) includinga primary shaft portion (192) having a first diameter (D 1 ),an end shaft portion (194) having a second diameter (D 2 ) and having a plurality of shaft splines (198) extending radially outwardly therefrom, anda conic transition portion (196) intermediate said primary and end shaft portions (192, 194), said conic transition portion (196) making a predetermined angle (β) with respect to said axis of said rotor shaft (128R or 130R); anda rotor hub (204) having a centerline (212), said rotor hub (204) having a shaft aperture (206) having a plurality of hub splines (208) extending radially inwardly therefrom;said plurality of hub splines (208) and said plurality of shaft splines (198) being interleaved in combination to provide a rotational interlock between said rotor hub (204) and said rotor shaft (128R or 130R) in the rotor assembly (100); characterized in thateach of said hub splines (208) having an outwardly tapered lower portion (210) that makes a predetermined angle (θ) with respect to said centerline (212); andsaid predetermined angle (θ) of said outwardly tapered lower portions (210) of said hub splines (208) being equal to said predetermined angle (β) of said conic transition portion (196) of said rotor shaft (128R or 130R) wherein said tapered lower portions (210) of said hub splines (208) abuttingly engage and are mechanically supported by said conic transition portion (196) of said rotor shaft (128R or 130R) in the rotor assembly (100).
Abstract:
An integrated spline/cone seat subassembly (190) for an unmanned aerial vehicle (10) having a rotor assembly (100) that includes ducted, counter-rotating rotors (200, 202), comprising:a rotor shaft (128R or 130R) having an axis, said rotor shaft (128R or 130R) includinga primary shaft portion (192) having a first diameter (D 1 ),an end shaft portion (194) having a second diameter (D 2 ) and having a plurality of shaft splines (198) extending radially outwardly therefrom, anda conic transition portion (196) intermediate said primary and end shaft portions (192, 194), said conic transition portion (196) making a predetermined angle (β) with respect to said axis of said rotor shaft (128R or 130R); anda rotor hub (204) having a centerline (212), said rotor hub (204) having a shaft aperture (206) having a plurality of hub splines (208) extending radially inwardly therefrom;said plurality of hub splines (208) and said plurality of shaft splines (198) being interleaved in combination to provide a rotational interlock between said rotor hub (204) and said rotor shaft (128R or 130R) in the rotor assembly (100); characterized in thateach of said hub splines (208) having an outwardly tapered lower portion (210) that makes a predetermined angle (θ) with respect to said centerline (212); andsaid predetermined angle (θ) of said outwardly tapered lower portions (210) of said hub splines (208) being equal to said predetermined angle (β) of said conic transition portion (196) of said rotor shaft (128R or 130R) wherein said tapered lower portions (210) of said hub splines (208) abuttingly engage and are mechanically supported by said conic transition portion (196) of said rotor shaft (128R or 130R) in the rotor assembly (100).
Abstract:
A substrate includes a metal diamond-like-carbon coating composed of a first laver and second layer deposited thereupon and having a thickness of about 0.5 micrometer to 10 micrometers. The first layer is composed of a transition metal and includes a first surface and a second surface in contact with the substrate. The second layer is composed of carbon and a transition metal selected from the group consisting of tungsten, niobium, titanium and combinations thereof, and also includes a first surface and a second surface in contact with the first surface of the first layer. The metal-containing diamond-like-carbon coating compositions possesses an abrasive wear rate of no more than about 10 x 10 -15 m3 m-1 N-1 over a negative biasing potential range of about -50 volts to -750 volts.
Abstract:
An integrated spline/cone seat subassembly (190) for an unmanned aerial vehicle (10) having a rotor assembly (100) that includes ducted, counter-rotating rotors (200, 202), comprising:a rotor shaft (128R or 130R) having an axis, said rotor shaft (128R or 130R) includinga primary shaft portion (192) having a first diameter (D 1 ),an end shaft portion (194) having a second diameter (D 2 ) and having a plurality of shaft splines (198) extending radially outwardly therefrom, anda conic transition portion (196) intermediate said primary and end shaft portions (192, 194), said conic transition portion (196) making a predetermined angle (β) with respect to said axis of said rotor shaft (128R or 130R); anda rotor hub (204) having a centerline (212), said rotor hub (204) having a shaft aperture (206) having a plurality of hub splines (208) extending radially inwardly therefrom;said plurality of hub splines (208) and said plurality of shaft splines (198) being interleaved in combination to provide a rotational interlock between said rotor hub (204) and said rotor shaft (128R or 130R) in the rotor assembly (100); characterized in thateach of said hub splines (208) having an outwardly tapered lower portion (210) that makes a predetermined angle (θ) with respect to said centerline (212); andsaid predetermined angle (θ) of said outwardly tapered lower portions (210) of said hub splines (208) being equal to said predetermined angle (β) of said conic transition portion (196) of said rotor shaft (128R or 130R) wherein said tapered lower portions (210) of said hub splines (208) abuttingly engage and are mechanically supported by said conic transition portion (196) of said rotor shaft (128R or 130R) in the rotor assembly (100).