A coaxial transmission/center hub subassembly for a rotor assembly

摘要

A coaxial transmission/center hub subassembly (110) for a rotor assembly (100) of an unmanned aerial vehicle (10) having ducted, coaxial counter-rotating rotors (200, 202) defining a rotational axis (12) for the unmanned aerial vehicle (10), the unmanned aerial vehicle (10) having a toroidal fuselage (20) with a plurality of inwardly extending support struts (24) and including a powerplant subsystem (50), the rotor assembly (100) including upper and lower swashplate subassemblies (80), comprising: center hub support structure means (160, 146) intermediate said counter-rotating rotors (200, 202) for mounting said coaxial transmission/center hub (110) assembly in fixed coaxial relation to the toroidal fuselage (20) utilizing the plurality of inwardly extending support struts (24); a multi-member transmission housing (140); and a single stage transmission subsystem (120); characterized in that said multi-member transmission housing (140) includes upper and lower standpipe housings (142, 144) secured in combination with said center hub support structure means (160, 146) in opposed relation along the rotational axis (12) of the unmanned aerial vehicle (10), said upper and lower standpipe housings (142, 144) having external surfaces (142E, 144E) that function as sliding surfaces for the upper and lower swashplate subassemblies (80), respectively; and said single stage transmission subsystem (120) includes an upper bevel gear (128) that includes an upper rotor shaft (128R) rotatably mounted in combination with said upper standpipe housing (142), a lower bevel gear (130) that includes a lower rotor shaft (130R) rotatably mounted in combination with said lower standpipe housing (144), said upper and lower rotor shafts (128R, 130R) providing means for mounting the counter-rotating rotors (200, 202) in combination with said coaxial transmission/center hub subassembly (110), and an input gear (122) rotatably mounted in said center hub support structure means (160, 146) and being mechanically coupled in combination with said upper and lower bevel gears (128, 130) and the powerplant subsystem (50) to couple torque to the counter-rotating rotors (200, 202). <IMAGE>