Rotor hub fairing system for a counter-rotating, coaxial rotor system
First Claim
1. A rotor hub fairing system for a coaxial rotor system comprising:
- an upper hub fairing defined about an axis;
a lower hub fairing defined about said axis; and
a shaft fairing between said upper hub fairing and said lower hub fairing, said shaft fairing defining an airfoil having a contoured midsection to reduce drag on the coaxial rotor system, said upper hub fairing and said lower hub fairing being rotatable with respect to said shaft fairing.
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Accused Products
Abstract
A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system is sized and configured to reduce the overall drag on a dual, counter-rotating, coaxial rotor system. Preferably, the rotor hub fairing is fully integrated. The shaft fairing preferably includes a minimal thickness at the midsection to reduce drag with an increasing thickness adjacent the upper and lower hub fairings to reduce the flow separation on the hub fairing surfaces without overly excessive drag. Other aerodynamic structures, such as a horizontal splitter and/or a plurality of turning vanes may be mounted to the shaft fairing to facilitate flow around the upper and lower hub fairings to reduce flow separation and drag.
53 Citations
29 Claims
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1. A rotor hub fairing system for a coaxial rotor system comprising:
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an upper hub fairing defined about an axis; a lower hub fairing defined about said axis; and a shaft fairing between said upper hub fairing and said lower hub fairing, said shaft fairing defining an airfoil having a contoured midsection to reduce drag on the coaxial rotor system, said upper hub fairing and said lower hub fairing being rotatable with respect to said shaft fairing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A rotor hub fairing system for a coaxial rotor system comprising:
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an upper hub fairing defining an upper hub fairing diameter; a lower hub fairing defining a lower hub fairing diameter; and a shaft fairing between said upper hub fairing and said lower hub fairing, said shaft fairing defining a shaft fairing chord to at least one of said upper and lower hub fairing diameters (c/D) of between 0.90 D to 1.25 D, said upper hub fairing and said lower hub fairing being rotatable with respect of said shaft fairing. - View Dependent Claims (23, 24, 25, 26, 27)
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28. A coaxial rotor system comprising:
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an upper rotor system including an upper rotor hub which rotates about an axis of rotation; an upper hub fairing which at least partially surrounds a portion of said upper rotor hub; a lower rotor system including a lower rotor hub which rotates about said axis of rotation; a lower hub fairing which at least partially surrounds a portion of said lower rotor hub; and a shaft fairing between said upper hub fairing and said lower hub fairing, said shaft fairing having a pitching axis generally parallel to said axis of rotation, said upper hub fairing and said lower hub fairing being rotatable with respect to said shaft fairing.
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29. A rotor hub fairing system for a coaxial rotor system comprising:
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an upper hub fairing defined about an axis; a lower hub fairing defined about said axis; a shaft faring between said upper hub fairing and said lower hub fairing, said shaft fairing including a thickness distribution in which a minimal thickness occurs within a contoured midsection; and a splitter airfoil mounted transverse to said shaft fairing.
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Specification