Patent Description:
Composite components, such as fan blades, vanes, stators, etc., for gas turbine engines fabricated using <NUM>-D weaving are being utilized to save weight and provide increased through-thickness stiffness, strength and interlaminar damage tolerance properties that are often very critical to the design of such complex engine structures. However, <NUM>-D woven composite components that are fabricated on a conventional loom, with yarns that traverse only the longitudinal (warp) and transverse (weft) directions, have very low torsional strength and stiffness properties. Traditional <NUM>-D woven components, thus, need to be reinforced separately with surface off-axis <NUM>-D plies (or layers) to provide the torsional stiffness and strength properties needed for the design. Such secondary application of <NUM>-D layers to provide the needed torsional properties adds additional cost and additional manual steps to the manufacturing process of these components. It also reduces the advantages afforded by the automated <NUM>-D weaving process.

Accordingly, it is desirable to fabricate turbine engine components with automated <NUM>-D woven fabrics that have the off-axis yarns integrated into the fabric during the weaving process itself.

<CIT> discloses a fan blade formed from a three dimensionally woven composite.

<CIT> discloses a three-dimensional fabric formed from a five yarn system.

In a first aspect of the invention, there is provided a fan blade includes a fan blade body formed from a composite material, the composite material including a three dimensional preform, the three dimensional preform including: a plurality of warp fibres disposed in a warp direction in a first plane; a plurality of filling fibres disposed in a fill direction, wherein the fill direction is perpendicular to the warp direction in the first plane; a plurality of z-yarn fibres disposed in a z-yarn direction, wherein the z-yarn direction intersects the warp direction through the first plane; and a plurality of bias fibres disposed in a bias direction, wherein the bias direction is not aligned with the warp direction and the fill direction and the bias direction is disposed in the first plane.

The fan blade body may include a root portion and an airfoil portion.

The root portion may be thicker than the airfoil portion.

The fan blade body may be formed from a plurality of composite layers.

According to a second aspect of the invention, there is provided a gas turbine engine comprising the fan blade of the first aspect of the invention, optionally including any optional features thereof.

Other aspects, features, and techniques of the embodiments will become more apparent from the following description taken in conjunction with the drawings.

The subject matter which is regarded as the present disclosure is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings, which is given by way of example only, in which:.

Embodiments provide composite components with three dimensional preforms including off-axis reinforcements. Off-axis or biased reinforcement of the three dimensional preforms can provide increased torsional stiffness and strength to composite components.

Referring to <FIG> a schematic representation of a gas turbine engine <NUM> is shown. The gas turbine engine includes a fan section <NUM>, a compressor section <NUM>, a combustor section <NUM>, and a turbine section <NUM> disposed about a longitudinal axis A. The fan section <NUM> drives air along a bypass flow path B that may bypass the compressor section <NUM>, the combustor section <NUM>, and the turbine section <NUM>. The compressor section <NUM> draws air in along a core flow path C where air is compressed by the compressor section <NUM> and is provided to or communicated to the combustor section <NUM>. The compressed air is heated by the combustor section <NUM> to generate a high pressure exhaust gas stream that expands through the turbine section <NUM>. The turbine section <NUM> extracts energy from the high pressure exhaust gas stream to drive the fan section <NUM> and the compressor section <NUM>.

The gas turbine engine <NUM> further includes a low-speed spool <NUM> and a high-speed spool <NUM> that are configured to rotate the fan section <NUM>, the compressor section <NUM>, and the turbine section <NUM> about the longitudinal axis A. The low-speed spool <NUM> may connect a fan <NUM> of the fan section <NUM> and a low-pressure compressor portion <NUM> of the compressor section <NUM> to a low-pressure turbine portion <NUM> of the turbine section <NUM>. The high-speed spool <NUM> may connect a high pressure compressor portion <NUM> of the compressor section <NUM> and a high pressure turbine portion <NUM> of the turbine section <NUM>. Guide vanes <NUM> and stators <NUM> can be utilized to direct flow within the turbine section <NUM>.

The fan <NUM> includes a fan rotor or fan hub <NUM> that carries a fan blade <NUM>. The fan <NUM> can include a fan case <NUM>. The fan blade <NUM> radially extends from the fan hub <NUM>. In certain embodiments, the fan blade <NUM> is partially or fully covered by a fan blade cover <NUM>.

In certain embodiments, components of the gas turbine engine <NUM> can be formed from composite materials, including composite materials with three dimensional preforms as described herein. In certain embodiments, the three dimensional preforms can include an off-axis reinforcement such as bias yarns. Components that may be formed from composite materials include, but are not limited to, the fan case <NUM>, the fan blade <NUM>, the fan blade cover <NUM>, the guide vanes <NUM>, and the stator <NUM>. Advantageously, components formed from <NUM>-D woven fabrics with integral bias reinforcement can have a lighter weight and be more resistant to delamination failures while withstanding greater torsional forces.

Referring to <FIG>, a fan blade <NUM> for use with the gas turbine engine <NUM> is shown. In the illustrated embodiment, the fan blade <NUM> is a lightweight composite fan blade that includes a root <NUM> and an airfoil <NUM> that extends from the root <NUM>. In certain embodiments, the fan blade cover <NUM> can be formed of a similar construction as the fan blade <NUM>.

The root <NUM> may be configured as a dovetail root, a fir tree root, or the like that operatively connects the fan blade <NUM> to the fan hub <NUM>. The root <NUM> includes a neck <NUM>, a base portion <NUM>, and a transition portion <NUM>. The neck <NUM> is a tapered portion of the root <NUM> that extends between the base portion <NUM> and the transition portion <NUM>. The neck <NUM> has a thickness that is less than a thickness of the base portion <NUM>. The neck <NUM> has a thickness that is greater than a thickness of the transition portion <NUM>. The transition portion <NUM> provides a smooth transition from the root <NUM> to the airfoil <NUM>.

The airfoil <NUM> radially extends from the root <NUM>. In the illustrated embodiment, the root <NUM> is thicker than the airfoil <NUM>. The airfoil <NUM> includes a leading edge <NUM>, a trailing edge <NUM>, a suction side <NUM>, a pressure side <NUM>, and a tip <NUM>. The leading edge <NUM> is spaced apart from and disposed opposite the trailing edge <NUM>. The suction side <NUM> and the pressure side <NUM> each axially extends between the leading edge <NUM> and the trailing edge <NUM>. The suction side <NUM> and the pressure side <NUM> each radially extend from the root <NUM> to the tip <NUM>. The suction side <NUM> and pressure side <NUM> each connect the leading edge <NUM> to the trailing edge <NUM>.

The pressure side <NUM> is configured as a concave surface. The suction side <NUM> is disposed opposite the pressure side <NUM> and is configured as a convex surface. The tip <NUM> is spaced apart from the root <NUM>. The tip <NUM> extends between distal ends of the leading edge <NUM> and the trailing edge <NUM>. The tip <NUM> extends between distal ends of the pressure side <NUM> and the suction side <NUM>.

In the illustrated embodiment, the fan blade <NUM> can be formed from a composite material. In certain embodiments, portions of the fan blade <NUM> can be formed from composite materials, while in other embodiments, the entire body of the fan blade <NUM> is formed from composite materials. In certain embodiments, the fan blade <NUM> can be formed from multiple composite layers formed together.

Referring to <FIG>, a three-dimensional preform <NUM> for use with a composite material is shown. In the illustrated embodiment, the three-dimensional preform <NUM> includes filling yarn or fibre <NUM>, warp yarn or fibre <NUM>, z-yarn or fibre <NUM>, and bias yarn or fibre <NUM>. In the illustrated embodiment, the three-dimensional preform <NUM> can be used with a composite material to form composite components for use in a gas turbine engine, such as the gas turbine engine <NUM> shown in <FIG>. The three-dimensional preform <NUM> can be utilized in composite materials to form components including, but not limited to the fan case <NUM>, the fan blade <NUM>, the fan blade cover <NUM>, the guide vanes <NUM>, and the stator <NUM> as shown in <FIG>. In certain embodiments, the three-dimensional preform <NUM> can be utilized in other applications including armour and automotive applications. Advantageously, the use of the three-dimensional preform <NUM> within a composite material allows for lighter, thinner, and more efficient components while allowing for desired strength, stiffness and damage tolerance.

In the illustrated embodiment, the three-dimensional preform <NUM> can be any suitable fabric style or pattern or fibre and matrix combination. In certain embodiments, the three-dimensional preform <NUM> is formed or woven from carbon fibre or glass fibre, or aramid fibre, or silicon carbide fibre or any combination of these fibres in order to achieve desired properties in different regions of the composite structure. Further, three-dimensional preform <NUM> can be utilized with epoxy or any other suitable matrix such as but not limited to bismaleimide, polyimide, thermoplastic, etc., to form the composite components as described herein. In certain embodiments, the three-dimensional preform <NUM> can be formed on a loom, while in other embodiments, the three-dimensional preform <NUM> can be formed using any suitable apparatus or method.

In the illustrated embodiment, the three-dimensional preform <NUM> includes filling yarn <NUM> disposed in a fill direction <NUM>. In the illustrated embodiment, three-dimensional preform <NUM> includes warp yarn <NUM> disposed in a warp direction <NUM>. In the illustrated embodiment, the warp direction <NUM> is perpendicular to the fill direction <NUM>. In the illustrated embodiment, the fill direction <NUM> and the warp direction <NUM> form a plane <NUM>. In certain embodiments, each plane <NUM> can define a layer of filling yarn <NUM> and warp yarn <NUM>. Multiple planes <NUM> can be stacked along the z-yarn direction <NUM> to form the three-dimensional preform <NUM>.

In the illustrated embodiment, z-yarn <NUM> is disposed in a z-yarn direction <NUM>. In the illustrated embodiment, the z-yarn direction <NUM> is disposed through each of the planes <NUM> defined by the fill direction <NUM> and the warp direction <NUM>. In certain embodiments, the z-yarn direction <NUM> is perpendicular or at an angle to the warp direction <NUM>. In the illustrated embodiment, the z-yarn <NUM> can allow for additional interlaminar strength between each of the layers of filling yarn <NUM> and warp yarn <NUM>.

In the illustrated embodiment, the three-dimensional preform <NUM> includes bias yarns <NUM>. In the illustrated embodiment, the bias yarns <NUM> can provide off-axis reinforcement of the three-dimensional preform <NUM>. The bias yarns <NUM> are disposed to not be aligned with the fill direction <NUM> and the warp direction <NUM>. The bias yarns <NUM> are disposed within the plane <NUM> defined by the fill direction <NUM> and the warp direction <NUM>, yet not aligned with the fill direction <NUM> and the warp direction <NUM>.

In the illustrated embodiment, during the forming process the bias yarns <NUM> can be manipulated to be disposed in an off-axis direction. Advantageously, the use of bias yarns <NUM> allows for off-axis reinforcement. In the illustrated embodiment, the three-dimensional preform <NUM> can be utilized in fan blades, such as fan blade <NUM> shown in <FIG> and <FIG>. In fan blades <NUM> the use of bias yarns <NUM> can provide adequate torsional stiffness and strength. Further, the three-dimensional preform <NUM> can be constructed to provide different composite material properties in various regions of the fan blade, such as the camber portion, an airfoil portion, and the root portion of the fan blade. In certain embodiments, the three-dimensional preform <NUM> can be formed to allow a root portion of a fan blade to be thicker than the airfoil portion of the fan blade.

Generally, the use of bias yarns <NUM> in the three-dimensional preform <NUM> can allow for lighter, thinner and more efficient components while meeting required strength and stiffness requirements. For example, for components for use within gas turbine engines, components can be designed to withstand bird strikes and still be tuned to avoid certain operating frequencies. The fibre type, size or filament count, spacing or ends and picks per unit length and orientation of the yarns <NUM>, <NUM>, <NUM>, and <NUM> within the three-dimensional preforms <NUM> can allow for tailored properties of the composite material and apparatus. Additionally, integrally weaving the bias yarns with the filling, warp and z-yarns provides an automated process to fabricate composite components with the desired interlaminar strength and torsional properties all in one manufacturing step.

While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the scope of the claims.

Claim 1:
A fan blade (<NUM>) comprising:
a fan blade body formed from a composite material, the composite material including a three dimensional preform (<NUM>), the three dimensional preform including:
a plurality of warp fibres (<NUM>) disposed in a warp direction (<NUM>) in a first plane (<NUM>);
a plurality of filling fibres (<NUM>) disposed in a fill direction (<NUM>), wherein the fill direction is perpendicular to the warp direction in the first plane;
a plurality of z-yarn fibres (<NUM>) disposed in a z-yarn direction (<NUM>), wherein the z-yarn direction intersects the warp direction through the first plane; and
a plurality of bias fibres (<NUM>) disposed in a bias direction, wherein the bias direction is not aligned with the warp direction and the fill direction and the bias direction is disposed in the first plane.