2. Background of the Invention Modern aircraft jet engines are among the most compact sources of power known. Jet engines propel virtually all modern military and large civil transport aircraft, particularly high-speed aircraft. Most manufacturers and buyers favor the turbofan, a turbojet with an oversized low-pressure compressor that drive extra airflow as a relatively cool and slow propulsive jet. Turbofans exhibit better propulsive efficiency, reduced fuel consumption, and dramatically lower noise level than ordinary turbojet engines. Similar gas turbine engines often drive land vehicles, warships, merchant ships, electric utility plants, pipeline pumps, and perform many other tasks demanding high sustained power reliability.

A turbofan engine is a modern variation of the basic gas turbine engine, basically comprising gas turbines combined with a large fan at the front of the engine.

A core engine is surrounded by a fan in the front and a turbine at the rear. A portion of the turbine work supplies power to the fan. Incoming air captured by the engine inlet passes a spinner, typically a cone fixed to the hub of the fan, which directs airflow into the fan blades and away from the center of the fan. Air then passes the fan, some of which diverts into a core compressor and then a burner where the air is mixed with fuel and combusted. The hot exhaust passes through the core and fan turbines, which drives the fan. The exhaust then emits through a nozzle, as in a basic turbojet, providing a portion of the engine thrust. Air that is not diverted into the core compressor passes through the fan and bypasses the turbine, much like the air through a propeller. The fan slightly compresses air that bypasses the fan, so that the turbofan generates some of its thrust from the core and some of its thrust from the fan.

Some aircraft, like airlines and cargo planes, operate primarily in a cruise condition. For these airplanes, high engine efficiency and low fuel usage are more

important than excess thrust. The additional fuel required to drive the fan as well as the core is relatively small. Consequently, a turbofan generates more thrust for nearly the same amount of fuel used by the core, thus providing a very fuel efficient power source.

Various aspects of current research in turbojet and turbofan engines attempt to further improve turbofan efficiency to maximize this feature. A straightforward technique for improving efficiency includes making an equally powerful but lighter engine. Reducing the weight of the engine tends to improve efficiency, but design changes for eliminating weight should not degrade the integrity of the engine. For example, the spinner should remain resistant to impact with foreign objects, such as birds or sand. In addition, the spinner should remain balanced and in position at the front of the engine, and should be simple to maintain.

For example, an efficiency limitation of conventional spinners relates to the structural requirements for attaching the spinner to the remainder of the engine.

Conventional spinners typically include counterbores formed in the spinner to accommodate bolts for attaching the spinner to the engine. The removal of the material to form the counterbores, however, may tend to degrade the structural integrity of the spinner. To restore the structural integrity of the spinner, additional material is typically added to the interior of the spinner. The additional material, however, adds weight, thus tending to diminish the efficiency of the engine.

SUMMARY OF THE INVENTION The present invention relates to a light two-piece spinner assembly for securing fan blades within a turbine engine and directing airflow into the turbine engine. In accordance with the present invention, the spinner assembly comprises an inner cone configured to provide structural support to the assembly and retain the fan blades attached to the fan disc. In accordance with another aspect of the present invention, a frusto-conical outer cone is placed over the inner cone such that the two piece assembly forms a substantially smooth outer conical surface. In accordance with yet another aspect of the present invention, the spinner assembly serves as an energy

absorption device for FODs (foreign objects and debris) that may be ingested into the engine and/or impact the spinner assembly.

BRIEF DESCRIPTION OF THE DRAWINGS Additional aspects of the present invention will become evident upon reviewing the non-limiting embodiments described in the specification and claims taken in conjunction with the accompanying figures, wherein like numerals designate like elements, and: Figure 1 is a cross-sectional elevational view of a typical turbine engine with a spinner assembly according to various aspects of the present invention; Figure 2 is an axial cross-sectional view of a fan disk and fan blade ; Figure 3 is a cross-sectional elevational view of the spinner assembly of Figure 1; Figure 4 is a cross-sectional elevational view of the inner cone of Figure 3; Figure 5 is an axial view of the inner cone; Figure 6 is a detailed cross-sectional view of an edge of the inner cone and an outer cone of the spinner assembly of Figure 1; Figure 7 is a cross-sectional elevational view of the outer cone; and Figure 8 is a detailed cross-sectional view of the outer cone including outer cone connector holes.

DETAILED DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way.

Rather, the following description provides a convenient illustration for implementing a preferred embodiment of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. Various aspects of the present invention may also be combined with other systems, such as those described in U. S. patent application 09/613,416, filed July 10,2000 by Raymond Hemmele and Steve Stenard, entitled DOUBLE

CONE SPINNER ; U. S. patent application 09/638,296, filed August 14,2000 by Raymond Hemmele, entitled POSITIVE-LOCKING DUAL CONE SPINNER ; and U. S. patent application 09/642,903, filed August 21,2000 by Raymond Hemmele, entitled SPINNER LOCKING SYSTEM, each of which is hereby incorporated by reference.

The present invention relates generally to a spinner assembly 50. Spinner assembly 50 suitably comprises a component of a turbine engine 10 such as that shown in Figure 1. Generally, engine 10 supplies power to a shaft 20 that rotates a fan disk 30. Fan disk 30 suitably engages a plurality of fan blades 40 and spinner assembly 50 such that rotation of shaft 20 causes spinner assembly 50, fan disk 30, and fan blades 40 to rotate together.

More particularly, engine 10 rotates shaft 20. Shaft 20 suitably rotates fan disk 30. Fan disk 30 is suitably attached to shaft 20 by a locking mechanism 25.

Generally, locking mechanism 25 comprises any device which prevents fan disk 30 from becoming detached from shaft 20 during operation of the engine, such as, for example, bolts, screws, welds, and the like.

Fan disk 30 suitably supports fan blades 40 that are circumferentially spaced about fan disk 30 and shaft 20. The fan blades 40 are attached to the fan disk 30 in any appropriate manner. In the present embodiment, with momentary reference to Figure 2, fan disk 30 suitably contains a plurality of dove-tailed grooves 32 formed on the outer surface of the fan disk 30 for retaining a mating portion of fan blades 40.

Dove-tailed grooves 32 suitably extend lengthwise across the axial surface of fan disk 30. Grooves 32 suitably allow fan blade 40 to slide into fan disk 30 from the fore end such that fan blades 40 are radially retained and attached to fan disk 30.

Spinner assembly 50 is attached to engine 10 such that fan blades 40 are retained in position and attached to fan disk 30. Spinner assembly 50 suitably supplies a restraining force against fan blade 40 to inhibit fan blade 40 from axial removal from fan disk 30. In accordance with the preferred embodiment of the present invention, the fan disk 30 provides a mounting surface for the spinner that is substantially perpendicular to and substantially coaxial with the axis of rotation of the spinner assembly 50. The spinner assembly 50 is attached directly to fan disk 30 and abuts the forward edge of the fan blade 40. However, spinner assembly 50 may be

attached to other components of engine 10 such that blades 40 are retained. For example, spinner assembly 50 may be attached to the shaft 20, or other components between shaft 20, fan disk 30 and engine 10.

Referring now to Figures 3 and 4, spinner assembly 50 is suitably manufactured by machining forged anodized 7075 aluminum, but spinner assembly 50 may also be manufactured from any suitable, preferably substantially rigid, materials, such as stainless steel, titanium, alloys, composites and the like. Spinner assembly 50 suitably comprises an inner structure, such as an inner cone 51, and an outer structure, such as an outer frusto-conical cone 52. In accordance with the present exemplary embodiment, inner cone 51 suitably comprises : a tip, such as a substantially conical tip 60; a connecting structure, such as a cylindrical connector 63; a fastening structure configured to be fastened to the engine 10, such as a radial flange 66; and, in certain configurations, a lower portion, such as a lower conical section 67. In the preferred embodiment, the outer surface of tip 60 is about twenty six degrees (26°) from a central longitudinal axis of the inner cone 51, though the angle may vary depending on particular applications of spinner assembly 50. Further, the inner cone 51 may be configured in any suitable shape, such as a parabola or other desired shape, and may be solid or have a hollow or partially hollow interior. In the present embodiment, the inner cone 51, including the tip 60, the connector 63, and the outer cone 52, and various other components are substantially hollow to reduce the overall mass of the spinner assembly 50.

At a base 61 of tip 60, a connector 63 extends axially toward the radial flange 66. The connector 63 suitably structurally connects the tip 60 to the radial flange 66.

For example, one end of the connector 63 is suitably attached to, such as integrally formed with, the flange 66 (or another portion of the spinner, such as the lower conical section 67), and the other end is suitably similarly attached to the tip 60. In the present preferred embodiment, connector 63 comprises a hollow cylinder parallel to the longitudinal axis of spinner assembly 50. However, in various alternative embodiments of the present invention, cylindrical connector 63 need not be parallel to the axis of spinner assembly 50, but rather may be angled with respect to the axis.

In accordance with one aspect of the presently described embodiment, a forward balance material 62 runs circumferentially about the outer surface of cylindrical connector 63 proximate to tip base 61. Forward balance material 62 suitably comprises an extra layer of material which may be removed so that spinner assembly 50 can be rotationally balanced.

In accordance with yet another aspect of the present embodiment, at least one drain hole may drain the interior of the inner cone 51. At approximately the midpoint of the present cylindrical connector 63, two drain holes 64 are formed through the surface of the connector 63, suitably on opposite sides of cylindrical connector 63.

Drain holes 64 suitably allow the drainage of liquids (e. g., water) which may accumulate on the inside of inner cone 51. Balance material 62 and drain holes 64 may be placed in various locations on cylindrical connector 63 or other portions of inner cone 51 and can vary in numbers and configurations according to the particular application of spinner assembly 50. For example, additional drain holes 64 may be provided and balance material 62 need not extend entirely circumferentially around cylindrical connector 63, but rather may be located in varying intervals about cylindrical connector 63.

Cylindrical connector 63 is joined to radial flange 66 extending radially from one end of cylindrical connector 63. Radial flange 66 is connected to the lower conical section 67. Additionally, radial flange 66 suitably facilitates connection of the spinner assembly 50 to the fan disk 30. Radial flange 66 also may facilitate attachment of the inner cone 51 to the outer cone 52. In the present embodiment, radial flange 66 suitably extends outward from the cylindrical connector 63, and is substantially perpendicular to and substantially coaxial with the longitudinal axis of spinner assembly 50. The outer surface of radial flange 66 is joins to lower conical section 67 of spinner assembly 50. In accordance with various alternative aspects of the present embodiment, flange 66 may be configured in any suitable manner. For example, radial flange 66 may be angled non-perpendicularly with respect to the axis of spinner assembly 50, depending on the particular application.

Radial flange 66 suitably includes or accommodates a fan disk fastener for attaching the spinner assembly 50 to the fan disk 30. With reference now to Figure 5,

the radial flange 66 suitably has a substantially flat surface configured to abut the fan disk 30. The fastener suitably includes a series of mounting holes 68 formed through the radial flange 66. As mentioned above, mounting holes 68 are provided to mount spinner assembly 50 to engine 10, and in particular fan disk 30. In the present embodiment, eight mounting holes 68 are provided and configured to allow a corrosion resistant stainless jacking bushing (CRES bushing) to be press fit into mounting holes 68, which in turn are configured for a 5/16 inch bolts for mounting inner cone 51. While the preferred embodiment includes eight mounting holes 68, any number of holes sufficient to mount spinner assembly 50 to engine 10 may likewise be used. In the present exemplary embodiment, spinner assembly 50 is bolted to fan disk 30, though screws, pins or any other suitable fastener may also be employed. Because radial flange is substantially parallel to the opposing surface of the fan disk 30, counterbores in the inner cone 51 are not required.

In accordance with another aspect of the present exemplary embodiment and with continuing reference to Figure 5, the spinner assembly 50 further suitably includes a securing mechanism for securing the inner structure to the outer structure.

In the present embodiment, the radial flange 66 further includes a cone fastener to facilitate connection of the inner cone 51 to the outer frusto-conical cone 52. The cone fastener suitably includes one or more inner connector holes 69 for connecting inner cone 51 and outer cone 52. In the present embodiment, four inner connector holes 69 are employed, though varying numbers of inner connector holes 69 may be used depending on the particular application of spinner assembly 50. Preferably, inner connector holes 69 are configured for the insertion of a CRES bushing of a size sufficient for a 10-32 bolt with an anodized aluminum washer to pass through and connect inner cone 51 and outer cone 52.

The spinner assembly 50 may also include a pilot mechanism for guiding the outer cone 52 into proper alignment with the inner cone 51. For example, in accordance with another aspect of the preferred embodiment of the present invention, at an outer edge 70 of radial flange 66, a circumferentially extending lip 71 surrounds radial flange 66. Lip 71 suitably facilitates connection between inner cone 51 and outer cone 52. Optionally, with momentary reference to Figure 6, lip 71 may be

configured with one or more scallops 72. In the preferred embodiment, four scallops 72 are provided equally spaced on lip 71. Scallops 72 are suitably configured as depressions for facilitating drainage of accumulated liquid from the cavity between outer cone 52 and inner cone 51.

Referring again to Figures 3 and 4, inner cone 51 is configured with a lower conical section 67. The lower conical section suitably includes an outer surface, configured in the present embodiment frusto-conically, surrounding the outer perimeter of the flange 66 and configured to form, when the outer cone 52 is placed over the inner cone 51, a single, substantially smooth outer surface of spinner assembly 50. In the present exemplary embodiment, lower conical section 67 is suitably configured at the same angle as tip 60 such that their respective surfaces occupy substantially the same conical plane. The surfaces 60,67 need not exist in the same plane, but rather, may be created at varying angles, curves, and/or slopes.

Inner cone 51 suitably further includes a lower conical base 73 located at the bottom of lower conical section 67. Lower conical base 73 suitably defines an inner cone cavity 74 giving inner cone 51 a hollow configuration. Alternatively, inner cone 51 may not be entirely hollow, and may be completely solid. In the present hollow embodiment, inner cone 51 contains an aft balance material 75. Aft balance material 75, like forward balance material 62, suitably allows inner cone 51 to be balanced during rotation. Like forward balance material 62, aft balance material 75 suitably comprises a circumferential ring of material which can be removed (e. g., by grinding, machining, or the like) to"trim balance"the spinner assembly 50. In the present embodiment, aft balance material 75 is located proximate to lower conical base 73.

However, aft balance material 75 may also be located elsewhere on the inner surface of inner cone 51. With reference now to Figure 8, outer cone 52 is suitably configured to substantially encase at least a portion of the inner structure, such as cylindrical connector 63 of inner cone 51. Outer cone 52 provides an exterior surface for the middle of the spinner assembly 50, substantially adjacent to and substantially flush with the exterior surface of the tip 60 and substantially adjacent to and substantially flush with the outer surface of the lower conical section 67. At least a portion of the tip 60 suitably protrudes from within the outer cone 52. The exterior surface of the outer

cone 52 thus suitably forms a substantially smooth outer surface from the tip 60, over the outer cone 52, and to the lower conical section 67. In the present embodiment, the outer cone 52 is substantially frusto-conical, comprising a truncated conical shape with the pointed end of the cone removed, thus leaving, from a side view, a trapezoidal shape. Outer cone 52 is suitably configured with the same angle as tip 60 of inner cone 51 and lower conical section 67 of inner cone 51, such that outer cone 52 may be placed over inner cone 51 to cooperatively form a substantially complete conical shape.

In the present embodiment, outer cone 52 suitably includes a pilot mechanism, or a component of a pilot mechanism, to facilitate fitting of the outer cone 52 to the inner cone 51. In the present embodiment, outer cone 52 includes a lower outer base 81. Still referring to Figure 7, lower outer base 81 suitably contains an inner lip 82 configured to facilitate connection between inner cone 51 and outer cone 52.

Accordingly, outer cone 52 slides over inner cone 51 and inner lip 82 mates with outer lip 71 to form a substantially smooth surface located at lower outer base 81. Similarly, tip 60 of inner cone 51 mates with an upper outer base 83 of outer cone 52 to form a similar substantially smooth surface.

In accordance with another aspect of the preferred embodiment, outer cone 52 has a frusto-conical inner surface 84 which may include an outer cone balance material 85. Similar to forward and aft balance materials 62,75, the balance material 85 is a circumferential ring about inner surface 84 which may be selectively ground or otherwise removed to balance outer cone 52. With reference now to Figure 8, outer cone 52 is suitably configured to cooperate with the fastener of the inner cone 51. For example, the outer cone 52 suitably includes a plurality of outer connector holes 86, such as four, substantially corresponding to inner connector holes 69. Outer connector holes 86 and inner connector holes 69 suitably are configured to receive a fastener, for example a CRES bushing and 10/32 bolt with an anodized aluminum washer to unite inner and outer cone 51,52.

In accordance with various aspects of the present invention, proximate to outer connector holes 86 are counter bores 87 suitably configured to allow a bolt for connecting inner cone 51 and outer cone 52 to pass through connector holes 69,86.

In the preferred embodiment, counter bores are angled relative to the axis of rotation of the spinner, for example about five degrees from the longitudinal axis of spinner assembly 50. This angle allows drainage from counter bores 87. The angle may vary or be optional depending on the particular application of spinner assembly 50.

In operation, the inner cone 51 is suitably affixed to the fan disk 30, for example using appropriate bolts and washers. The outer cone 52 may then be fitted over the inner cone. The pilot mechanism, such as the cooperating lip 71 and the inner lip 82, tends to guide the outer cone 52 into the proper position over the inner cone 51. The outer cone 52 may then be fixed to the inner cone 51, for example using bolts and washers extending through outer connector holes 86 and inner connector holes 69.

For inspection, repair, or replacement, the spinner assembly 50 may be similarly dissembled.

Thus, a spinner assembly according to various aspects of the present invention tends to provide a lighter assembly. The spinner does not require large counter bores that may tend to weaken the spinner. Accordingly, the spinner does not require additional material to maintain its structural integrity. While various principles of the invention have been described in illustrative embodiments, many combinations and modifications of the above described structures, arrangements, proportions, elements, materials and components used in the practice of the invention in addition to those not specifically described may be varied and particularly adapted for specific environments and operating requirements, without departing from the principles of the present invention.