Nose cone/spinner power takeoff

A coupling for a fan hub including an auxiliary unit attached to the coupling; the fan hub attached to the coupling opposite the auxiliary unit, wherein the misalignment-tolerant coupling is configured to translate rotary motion along an axis from the fan hub to the auxiliary unit to provide rotational power from a gas turbine engine to the auxiliary unit.

BACKGROUND

The present disclosure is directed to a coupling for use on a fan rotor.

Certain aircraft lack sufficient electrical power to run current electronic systems, for example, for avionics systems. One solution for increasing the available power is to modify the Airframe Mounted Accessory Drive (AMAD) to provide more power and install a larger generator on the AMAD. Another solution is to modify the Engine Mounted Accessory Drive (EMAD). Usually these solutions are difficult to achieve for at least two reasons: (1) no empty volume exists within the aircraft for a larger generator and AMAD or EMAD to grow into, and (2) changing the AMAD or EMAD and generator is cost prohibitive. Other options, however, are typically less attractive or not feasible for various reasons. For instance, a pop-up air scoop could be deployed to drive a Ram Air Turbine (RAT) that would drive a generator. This solution, imposes additional aerodynamic drag on the aircraft. The additional aerodynamic drag could adversely affect aircraft performance. The additional RAT incurs a large amount of weight and mechanical complexity compared to the amount of extra power generated so that it is inefficient from both a cost and energy standpoint.

Gas turbine engines include a fan with a fan hub or rotor supporting fan blades. The forward portion of the fan hub can include a nose cone. In certain fan hub designs, the nose cone can be removeable. The removable nose cone can be fastened by a set of nose cone fasteners.

What is needed is an alternative source of auxiliary power for a gas turbine engine without the unwanted drawbacks of modification of an AMAD or EMAD.

SUMMARY

In accordance with the present disclosure, there is provided a coupling for a fan hub comprising an auxiliary unit attached to the coupling; the fan hub attached to the coupling opposite the auxiliary unit, wherein the coupling is configured to translate rotary motion along an axis from the fan hub to the auxiliary unit to provide rotational power from a gas turbine engine to the auxiliary unit.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the fan hub supports fan blades.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the auxiliary unit is selected from the group consisting of an electrical generator, a hydraulic pump and an airframe mounted accessory drive.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a drive adapter having a coupling bolt pattern for attaching to the fan hub.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a flexible member attached to the drive adapter.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the flexible member comprises laminated sheets located on opposite sides of a central shaft.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a bearing system attached to the flexible member opposite the drive adapter.

In accordance with the present disclosure, there is provided a gas turbine engine coupling for a fan hub power takeoff comprising a fan located at a forward portion of the gas turbine engine, the fan comprising the fan hub supporting fan blades; a casing attached forward of the fan proximate the forward portion of the gas turbine engine; an auxiliary unit mounted in the casing; a coupling operatively coupled between the fan hub and the auxiliary unit, wherein the coupling is configured to translate rotary motion along an axis from the fan hub to the auxiliary unit to provide rotational power from the gas turbine engine to the auxiliary unit.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a drive adapter having a coupling bolt pattern for attaching to a fan hub flange bolt pattern to secure the drive adapter to the fan hub.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a flexible member attached to the drive adapter configured to dampen misalignment between the fan hub and the auxiliary unit.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the flexible member comprises laminated sheets located on opposite sides of a central shaft.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a bearing system attached to the flexible member opposite the drive adapter, the bearing system comprising a duplex bearing.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the coupling comprises a spline interface mounted between the duplex bearing and a drive shaft of the auxiliary unit.

In accordance with the present disclosure, there is provided a process for employing a gas turbine engine coupling for a fan hub power takeoff comprising locating a fan at a forward portion of the gas turbine engine, the fan comprising the fan hub supporting fan blades; attaching a casing forward of the fan proximate the forward portion of the gas turbine engine; mounting an auxiliary unit in the casing; attaching a coupling between the fan hub and the auxiliary unit; and translating rotary motion along an axis from the fan hub to the auxiliary unit to provide rotational power from the gas turbine engine to the auxiliary unit.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the process further comprising attaching the coupling to the fan hub employing a drive adapter having a coupling bolt pattern configured to match a bolt pattern of a fan hub flange bolt pattern to secure the drive adapter to the fan hub.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the process further comprising attaching a flexible member to the drive adapter; dampening misalignment between the fan hub and the auxiliary unit employing the flexible member.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the process further comprising attaching a bearing system to the flexible member opposite the drive adapter, the bearing system comprising a duplex bearing; and dampening rotational whirl with the duplex bearing.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the process further comprising mounting a spline interface between the duplex bearing and a drive shaft of the auxiliary unit.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the process further comprising supporting the bearing system with a bearing support attached to a centerbody of the casing.

A further embodiment of any of the foregoing embodiments may additionally and/or alternatively include the auxiliary unit is selected from the group consisting of an electrical generator, a hydraulic pump and an airframe mounted accessory drive.

Other details of the coupling for a fan hub are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.

DETAILED DESCRIPTION

Referring now toFIG.1andFIG.2, there is illustrated a forward portion of a gas turbine engine10. The gas turbine engine10includes a fan12. The fan12includes a fan hub14supporting fan blades16.

The gas turbine engine10includes an auxiliary unit18. The auxiliary unit18can be an electrical generator or a hydraulic pump or other form of airframe or engine mounted accessory. The auxiliary unit18can be housed within a case20. The case20provides structural support via support23to the auxiliary unit18as well as aerodynamic function for managing air flow22through the auxiliary unit18and fan12. A nose cone24is mounted on a case forward portion26of the case20. The nose cone24can manage the air flow22into or around the auxiliary unit18. A mount ring28can be employed to secure the auxiliary unit18to the case20.

A coupling30can operably couple the fan hub14and the auxiliary unit18so that rotary motion can be translated along Axis A from the fan hub14to the auxiliary unit18to provide rotational power from the gas turbine engine10to the auxiliary unit18.

As seen inFIG.2, a removeable fan spinner/nose cone32can be replaced to allow for the coupling30to attach with the fan hub14. The coupling30can include a drive adapter34. The drive adapter34includes a coupling bolt pattern36that matches a fan hub flange38bolt pattern to secure the drive adapter34to the fan hub14. The fan nose cone32can be removed to provide an interface for the coupling30. The fan nose cone32is attached to the fan hub flange38. Spinner bolts40can be removed from the fan hub flange38. The fan nose cone32can be removed from the fan hub flange38. The drive adaptor34can be bolted to the fan hub flange38to secure the coupling30to the fan hub14.

The coupling30includes a flexible member42attached to the drive adapter34. The flexible member42is configured to dampen misalignment between the fan hub14and the auxiliary unit18. The flexible member42can include laminated sheets44located on opposite sides of a central shaft46. In an exemplary embodiment, the laminated sheets44can be constructed from stainless steel sheets. The flexible member42can be rigid in response to torsional forces while remaining flexible in response to axial forces.

The coupling30includes a bearing system48attached to the flexible member42opposite the drive adapter34. The bearing system48supports the coupling30via a bearing support50. The bearing support50can be attached to a centerbody52of the case20. The bearing system48includes a duplex bearing54. The duplex bearing54is configured to dampen rotational whirl.

A spline interface56is mounted between the duplex bearing54and a drive shaft58of the auxiliary unit18. The use of the bearing system48allows for the drive shaft58of the auxiliary unit to be relatively rigid.

A technical advantage of the disclosed nose cone spinner/power takeoff can include that the engine remains BOM with the addition of the power take-off shaft.

Another technical advantage of the disclosed nose cone spinner/power takeoff can include the power take-off shaft becomes interchangeable with no need for a recertification of the engine.

Another technical advantage of the disclosed nose cone spinner/power takeoff can include powering an auxiliary unit via the low spool.

Another technical advantage of the disclosed nose cone spinner/power takeoff can include the capacity to significantly increase the electrical power to an aircraft with minimal redesign.

There has been provided a coupling for a fan hub. While the coupling for a fan hub has been described in the context of specific embodiments thereof, other unforeseen alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations which fall within the broad scope of the appended claims.