Electrical wiring system for a rotor hub

The electrical harness system is configured for routing a harness between a rotor yoke and a rotor blade. A recess in an inboard cap member is configured to house a connector and an associated harness. As the recess extends along a radial path in the chordwise direction of the rotor blade, the harness is configured to lie within the recess. Operationally induced centrifugal forces promote positioning the slack of harness within the recess, while the slack in the harness remains available for relative dynamic movements between the rotor blade and the rotor yoke. Such a routing of the harness reduces aerodynamic drag and minimizes damage that could otherwise occur to the harness.

BACKGROUND

1. Technical Field

The present application relates in general to an electrical wiring system for a rotor hub.

2. Description of Related Art

Certain aircraft include systems associated with a rotating airfoil, such as a rotor blade, that can require electrical power. For example, a rotor blade de-ice system can require electrical power. Conventionally, power is routed to the rotor blade with exposed brackets on the leading edge of the blade to mount an electrical connector. Such a configuration typically causes the bracket to extend out of the rotor blade contour and leaving the wiring harness exposed beyond the profile of the rotor hub. Part of the wiring harness is loose and must be handled carefully during manufacturing and when disconnected from the aircraft. Such a harness configuration increases the rotor hub drag and the vulnerability of the connector to foreign object damage (FOD). Such a configuration can further cause the harness to have a substantial loop in order to carry all the flap, lead/lag, and pitch motions while the centrifugal forces tend to pull the harness outward.

There is a need for an improved wiring system between the rotor hub and the rotor blade.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1in the drawings, a rotorcraft102is illustrated. Rotorcraft102has a rotor system101with a plurality of rotor blades103. Rotorcraft102further includes a fuselage104, landing gear106, and an empennage108. A main rotor control system can be used to selectively control the pitch of each rotor blade103in order to selectively control direction, thrust, and lift of rotorcraft102. It should be appreciated that even though the system of the present application is depicted on a rotorcraft102having certain illustrated features, it should be appreciated that the system of the present application can be implemented on other aircraft and aircraft configurations, as one of ordinary skill in the art would fully appreciate having the benefit of this disclosure.

Referring toFIG. 2, rotor hub101includes a plurality of rotor blades103coupled to a central yoke109, via a rotor grip107. Yoke109is coupled to a rotor mast105such that rotation of rotor mast105, in a direction113, causes the yoke109and rotor blades103to rotate about the rotor mast axis of rotation. It should be appreciated that even though rotor hub101is illustrated with four rotor blades103, the system of the present application is equally applicable to rotor hubs having an alternative number of rotor blades103.

Referring now also toFIGS. 3-6, an electrical wiring system301is illustrated. System301is configured for the routing of electrical lines in a dynamic environment. In the illustrated embodiment, system301includes a wiring harness303arouted between a powered unit305and a connector313a. System301further includes a connector313band wiring harness303b. One feature of system301is a contoured recess307in a cap member311located at the root end of spar309. In the illustrated embodiment, spar309is a partially hollow member; however, cap member311functions in part to seal off the interior portion of spar309. Connectors313aand313ballows the wiring harness303ato be routed in the interior of rotor blade103to powered unit305, thus protecting harness303afrom damage. In the illustrated embodiment, powered unit305is a de-icing heater blanket; however, it should be appreciated that powered unit305can be any power consuming device, such as a light, an actuator for a moveable airfoil, or a vibration reduction system, to name a few examples. Further, harnesses303aand303bcan alternatively be hydraulic hoses instead of power wire harnesses. Further, harnesses303aand303bcan provide a data or control signal in addition or in lieu of providing power. For example, harnesses303aand303bcan provide hydraulic power to a hydraulic actuator in rotor blade103.

Harness303bcan be secured with one or more harness clips located within recess307. Recess307forms a contoured radius along the chordwise direction at the root end portion of cap member311. Recess307and harness303bare configured such that an operationally generated centrifugal force315acts to position a slack portion of harness303binto the trailing edge side of recess307. A slack portion of harness303bcan be necessary to compensate for all the flap, lead/lag, and pitch motions of rotor blade103. In the illustrated embodiment, the harness303bis routed away from the body of the rotor blade103toward a lead/lag damper317; however, it should be appreciated that an alternative embodiment may not include lead/lag damper317. Harness303bis routed along the axis of lead/lag damper317, and further extends back towards the axis of rotation. A loop or slack in the harness303bcan be implemented where the lead/lag damper317joins yoke109, allowing for relative motion therebetween.

System301is configured to minimize aerodynamic drag penalties that may otherwise be associated with conventional harness routing. Further, system301allows connectors313aand313b, and its terminals, to be enclosed in recess307of blade103, away from potential environmental damage. Further, potential manufacturing damage to harness303ais reduced by reducing the exposed amount of harness303a. Further, coupling harness303bto the blade portion harness303aat connectors313aand313breduces damage to may otherwise occur to conventional wire attachments that are susceptible to fatigue induced breakage. Connector313ais mounted on a wall321near a leading edge portion of recess307. Wall321can be a flat surface suitable for mounting connector313a. In the illustrated embodiment, wall321is approximately normal to an inner surface of recess307such that the harness303bis directed inboard toward the rotor mast until approximately reaching a centerline100of the root end, in which recess307is contoured in an outboard direction until reaching the trailing edge termination. This trailing edge portion of recess307provides a secure housing for the slack portion of harness303bas centrifugal forces acts upon harness303b.

In the illustrated embodiment, rotor blade103is coupled to rotor grip107with bolts319aand319b. It can be particularly desirable to fold and stow rotor blades103. System301is configured to allow folding of rotor blade103without having to disconnect connectors313aand313bfrom each other. For example, bolt319bcan be removed such that rotor blade103is allowed to rotate about bolt319ain a rotation R1. In such a configuration, when rotor blade103is rotated towards its leading edge, slack in harness303bis generated and allowed to build within recess307. Such a configuration of system301saves time and maintenance costs associated with disconnecting a harness for rotor blade folding.

The particular embodiments disclosed herein are illustrative only, as the system may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Modifications, additions, or omissions may be made to the system described herein without departing from the scope of the invention. The components of the system may be integrated or separated. Moreover, the operations of the system may be performed by more, fewer, or other components.

Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosure. Accordingly, the protection sought herein is as set forth in the claims below.