The subject matter disclosed herein relates to the art of rotary wing aircraft and, more specifically, to rotor systems for rotary wing aircraft.
The rotor systems of rotary wing aircraft, for example, helicopters, are a major source of aerodynamic drag during operation of the helicopter. The rotor system typically includes a rotor hub with a number of rotor blades secured to and extending from the rotor hub. In many rotor systems, the rotor blades are connected to the rotor hub via an intermediate component or components, such as a yoke. The yoke is fixed to the rotor blade and rotatably secured to the rotor hub via a bearing set to allow for rotation of the rotor blade about a rotor blade axis, otherwise known as pitch change. Further, to enable and/or control pitch change of the rotor blades, pitch change arms connect to the yoke, such that movement of the pitch change arms adjust pitch of the rotor blades. Moreover, helicopter rotor systems often include large, bulky vibration absorbers at the rotor hub.
Rotor systems have previously included fairings in an attempt to reduce aerodynamic drag, but the fairings were unable to enclose the entire rotor system due to the design or requirements of one or more of the components described above. Often, one or more of the components is left protruding from the fairing or the resultant fairing-enclosed rotor system has much less than ideal impact on aerodynamics, because the attempt to make the rotor system more aerodynamic occurs after the rotor system has already been designed and configured, causing the fairing to be designed around existing features of the rotor system.
USPTO Backgrounds
USPTO Backgrounds