Variable diameter rotor blade actuation system

A variable diameter rotor system for an aircraft comprising:

• a main rotor shaft having an upper end, a lower end and an axis of rotation;
• a plurality of rotor blade assemblies, each rotor blade assembly having an inboard blade section and an outboard blade section, the outboard blade section being telescopically mounted to the inboard blade section;
• a screw drive rotatably disposed within the rotor blade assembly and engaged with the outboard blade section for telescoping the outboard blade section with respect to the inboard blade section, the jackscrew having an output pinion located at its inboard end,
• a rotor hub assembly mounted to the upper end of the rotor shaft, the inboard blade section of each rotor blade assembly being mounted to the rotor hub assembly such that the rotor blade assemblies are rotated by the rotor hub assembly;
• a blade actuation shaft concentrically disposed within the main rotor shaft, the blade actuation shaft having an upper end and a lower end;
• a planetary gear drive located within the rotor hub and engaging the upper end of the blade actuation shaft with the output pinion;
• a drive gear on the lower end of the main rotor shaft and having a first set of teeth thereon;
• a blade actuation drive gear on the lower end of the blade actuation drive shaft and having a first set of teeth thereon;
• a primary drive unit for transmitting rotary motion from the main rotor shaft to the blade actuation shaft, the primary drive unit including
• an input gear engaged with the first set of teeth on the drive gear,
• a primary drive,
• a master clutch disposed between the input gear and the primary drive for controlling transmission of rotary motion therebetween,
• an output gear engaged with the first set of teeth on a blade actuation drive gear,
• an output drive engaged with the output gear,
• a forward planetary gearset operative for transmitting rotary motion from the primary drive to the output drive,
• a forward clutch for engaging the forward planetary gearset with the primary drive and the output drive, the engagement of the forward planetary gearset causing the blade actuation shaft to rotate in the same direction as the rotation of the main rotor shaft,
• a reverse planetary gearset operative for transmitting rotary motion from the primary drive to the output drive, and
• a reverse clutch for engaging the reverse planetary gearset with the primary drive and the output drive, the engagement of the reverse planetary gearset causing the blade actuation shaft to rotate in the opposite direction from the rotation of the main rotor shaft;
• and
• a rotor blade actuation control unit for controlling engagement and disengagement of the forward and reverse clutches.