DESIGN: SynchroLite ~ Rotor - Hub - 2-blade Teetering - CVJ+HS

• To provide greater rotor control authority from a 2-blade teetering rotor, while reducing the 2P vibration, which would result if a conventional 2-blade teetering rotor was equipped with a hub spring.

• The rotorhead can be considered as a conventional 2-blade teetering rotor, with the following modifications;
• The teetering hinge is replaced by a constant velocity joint.
• The central ring in the constant velocity joint consists of a 'trim tube' that pivots about the CVJ axis and hangs down over the mast.
• This tube can be tilted longitudinally and laterally, in respect to the mast, by a couple of linear actuators.
• There are hub springs between the teetering head and this 'trim tube'.
• The pilot's cyclic stick has a trim tab.
• Actuation of the trim tab causes this tube to normalize itself with the commanded tip path plane (control plane).
• Movement of the cyclic stick does not move this tube. Movement of the cyclic stick causes the rotorhead to teeter about this tube, as if the tube was a conventional mast.
• This movement of the cyclic stick will therefor result in a 2P vibration. However, it will impart a stronger moment on the mast, which will result in a faster reorientation of the fuselage.
• Activation of the trim tab will reduce and eliminate the 2P vibration by bringing the trim-tube inline with axis of the tip-path-plane. However it will also reduce the stronger moment, which is resulting in a faster reorientation of the fuselage.
• The pilot has the option of;
• Holding down the trim tab while moving the cyclic. This will eliminate the 2P vibration but the response of the craft will be the same as that from a conventional teetering rotor.
• Moving the cyclic, then, after the craft has reoriented itself, depress the trim tab for a second or two. This will result in 2P vibration during the reorientation of the craft, however, the trim tab will remove the vibration during continuous flight in the new orientation.
• An additional feature of this idea is that should the rotor teeter due to an external un-commanded influence, the hub spring will impose a restoring moment on the rotor. This should reduce the possibility of a tail boom incursion.

• Miscellaneous:
• The mast, rotorhub and blades must be stronger, to handle the greater moments between the blades and the fuselage.
• No search for existing patents has been done.

• SynchroLite ~ Rotor - Hub - 2-blade Teetering
• SynchroLite ~ Rotor - Hub - 3-blade - CVJ+HS
• OTHER: Flight Dynamics - Rotor Hub - Constant Velocity Rotor w/ Hub Spring
• OTHER: Flight Dynamics - Rotor - Hub - Hub Spring (Hinge Spring)

• Tip-path-plane
• Control plane
• Trim plane (new)
• Mast plane
• The Concord

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