Patent Description:
Gas turbine engine designers are continually being challenged to provide gas turbine engines with improved performance at reduced weights. One design metric being pushed to provide improved performance is increasing turbine rotational speed. As the turbine rotational speed is increased, however, rotor disk bores also increase in size in order to accommodate increasing centrifugal loading. This can result in bore widths that are so large that heat treating the center of a bore may become challenging. Rotor disk sizing may also be impacted by rim pull which includes the mass of airfoils and interrupted (circumferentially discontinuous) features created by axially or angled airfoil attachment features.

Current turbine design standard includes separate airfoils that are mechanically attached to a disk using single or multiple tooth attachments; e.g., fir tree attachments. Provision of these attachments result in a live rim (full hoop or circumferentially continuous rim) that transfers radial loads from the airfoils as well as segmented portions of the disk between airfoil attachments. In addition, cover plates are typically employed to reduce leakage through attachments from one side of the disk to the other.

There is a need in the art for improved rotor blades and rotor assemblies with reduced weights and/or with improved cooling schemes. This includes rotor blades made using high temperature composites such as ceramic matrix composite (CMC) materials. It should be recognized that designing for such composite airfoils may require new rotor architectures to accommodate and exploit the unique capabilities and limitations of composite materials.

<CIT> discloses an arrangement of the prior art.

According to an aspect of the present invention, a rotor assembly is provided for a gas turbine engine. This rotor assembly includes a first rotor disk, a second rotor disk and a plurality of rotor blades. The first rotor disk is configured to rotate about a rotational axis. The second rotor disk is configured to rotate about the rotational axis. The rotor blades are arranged circumferentially around the rotational axis. Each of the rotor blades is mounted to the first rotor disk and to the second rotor disk. The rotor blades include a first rotor blade. The first rotor blade includes an attachment projecting axially along the rotational axis into a first pocket in the first rotor disk and a second pocket in the second rotor disk. The attachment has a dovetail cross-sectional geometry when viewed in a plane perpendicular to the rotational axis. A portion of the first rotor disk extends circumferentially across and thereby circumferentially covers the attachment.

An end of the first pocket may be axially enclosed by the first rotor disk.

The first rotor blade may also include a platform and a neck radially connecting the platform and the attachment. An end portion of the attachment may project axially along the rotational axis out from the neck and into the first pocket.

An axial end of the first pocket may be axially enclosed by the portion of the first rotor disk.

The first pocket may be radially enclosed within the first rotor disk.

The first rotor blade may also include an airfoil, a platform and a neck. The airfoil may be connected to and project radially out from the platform. The neck may extend radially between and connect the platform and the attachment. A first end portion of the attachment may project axially along the rotational axis away from the neck and into the first pocket. A second end portion of the attachment may project axially along the rotational axial away from the neck and into the second pocket.

A second portion of the first rotor disk may project axially into a gap that is axially adjacent the neck and extends radially between the first end portion of the attachment and the platform.

The first pocket may be formed by a circumferentially uninterrupted annular rim of the first rotor disk.

The first pocket may be formed by a circumferentially interrupted annular rim of the first rotor disk.

The rotor blades may also include a second rotor blade. The second rotor blade may include a second attachment projecting axially along the rotational axis into a third pocket in the first rotor disk and a fourth pocket in the second rotor disk. A second portion of the first rotor disk may extend circumferentially across and thereby circumferentially cover the second attachment.

The second rotor blade may circumferentially neighbor the first rotor blade.

The rotor blades may also include a second rotor blade. The second rotor blade may include a second attachment projecting axially along the rotational axis into a third pocket in the first rotor disk and a fourth pocket in the second rotor disk. The first rotor disk may have a slot that radially and circumferentially overlaps the second attachment.

A portion of the second rotor disk may extend circumferentially across and thereby circumferentially cover the attachment.

The first rotor blade may be configured from or otherwise include ceramic.

The first rotor blade may be configured from or otherwise include metal.

The first rotor blade may be configured from or otherwise include intermetallic material.

The rotor assembly may also include a plurality of disk mounts connecting the first rotor disk and the second rotor disk together.

According to the aspect of the present invention, the rotor assembly includes one or more reinforcing rings: accordingly, the rotor assembly includes a reinforcing ring located axially between and rotatable with the first rotor disk and the second rotor disk and/or a first reinforcing ring and/or a second reinforcing ring, wherein the first reinforcing ring is connected to an exterior of the first rotor disk, and the second reinforcing ring is connected to an exterior of the second rotor disk.

<FIG> illustrates a bladed rotor assembly <NUM> for rotational equipment with an axial centerline <NUM>, which centerline <NUM> may be or may be coaxial with an axis of rotation (e.g., a rotational axis) of the rotor assembly <NUM>. An example of such rotational equipment is a gas turbine engine for an aircraft propulsion system, an exemplary embodiment of which is described below in further detail with respect to <FIG>. However, the rotor assembly <NUM> of the present invention is not limited to such an aircraft application nor a gas turbine engine application. The rotor assembly <NUM>, for example, may alternatively be configured with rotational equipment such as an industrial gas turbine engine, a wind turbine, a water turbine or any other apparatus which includes a bladed rotor.

The rotor assembly <NUM> of <FIG> includes a plurality of rotor blades <NUM> and a rotor disk assembly <NUM>. Referring to <FIG> and <FIG>, each of the rotor blades <NUM> may be configured as a rotor blade singlet; e.g., a rotor blade that only includes a single airfoil. The present invention, however, is not limited to such an exemplary rotor blade configuration. In other embodiments, for example, one or more or each of the rotor blades <NUM> may alternatively be configured as a rotor blade doublet with a pair of airfoils.

Referring still to <FIG> and <FIG>, each rotor blade <NUM> includes a rotor blade mount <NUM> and a rotor blade airfoil <NUM>. The rotor blade mount <NUM> of <FIG> and <FIG> includes a mount platform <NUM>, a mount neck <NUM> and a mount attachment <NUM>.

The mount platform <NUM> is configured to form a portion of an inner peripheral border of a gas path <NUM> (e.g., a core gas path) that extends axially along the axial centerline <NUM> across the rotor assembly <NUM>; e.g., a gas path into which the airfoils <NUM> radially extend. The mount platform <NUM>, for example, extends radially relative to the axial centerline <NUM> between a platform inner end <NUM> and a platform outer end <NUM>. The platform outer end <NUM> carriers a gas path surface <NUM>, which forms the respective inner peripheral border portion of the gas path <NUM>. As best seen in <FIG>, the gas path surface <NUM> extends axially between a platform first (e.g., forward and/or upstream) side <NUM> and a platform second (e.g., aft and/or downstream) side <NUM>. As best seen in <FIG>, the gas path surface <NUM> extends laterally (e.g., circumferentially or tangentially) between opposing platform lateral sides <NUM> and <NUM>.

The mount platform <NUM> is configured with one or more lateral platform overhangs <NUM> and <NUM>; e.g., wings, flanges, projections, etc. One or both of these platform overhangs <NUM> and <NUM> may have a tapered geometry. A radial thickness of the mount platform <NUM> of <FIG>, for example, decreases (e.g., tapers) as the mount platform <NUM> and its first platform overhang <NUM> extend laterally from a laterally intermediate location towards or to the first lateral side <NUM>. This change in thickness provides the first platform overhang <NUM> with its tapered geometry. The radial thickness of the mount platform <NUM> of <FIG> also decreases as the mount platform <NUM> and its second platform overhang <NUM> extend laterally from the laterally intermediate location towards or to the second lateral side <NUM>. This change in thickness provides the second platform overhang <NUM> with its tapered geometry.

The mount neck <NUM> is located radially beneath the mount platform <NUM>. The mount neck <NUM> extends radially between and is connected (e.g., directly) to the mount platform <NUM> and the mount attachment <NUM>.

The mount neck <NUM> extends laterally between opposing neck lateral sides <NUM> and <NUM>. The neck first lateral side <NUM> is laterally recessed inward from the platform first lateral side <NUM> such that the first platform overhang <NUM> projects laterally out from the mount neck <NUM>. The neck second lateral side <NUM> is laterally recessed inward from the platform second lateral side <NUM> such that the second platform overhang <NUM> projects laterally out from the mount neck <NUM>.

Referring to <FIG>, the mount neck <NUM> extends axially along the axial centerline <NUM> between a neck first (e.g., forward and/or upstream) side <NUM> and a neck second (e.g., aft and/or downstream) side <NUM>. The neck first side <NUM> is axially recessed inward from the platform first side <NUM> such that the mount platform <NUM> and its elements <NUM> and <NUM> project axially out from the mount neck <NUM>. The neck second side <NUM> is axially recessed inward from the platform second side <NUM> such that the mount platform <NUM> and its elements <NUM> and <NUM> project axially out from the mount neck <NUM>.

Referring to <FIG> and <FIG>, the mount attachment <NUM> is located radially beneath the mount neck <NUM>. The mount attachment <NUM> of <FIG> and <FIG> is configured as a dovetail attachment; e.g., a flared attachment, a delta attachment, etc. As best seen in <FIG>, the mount attachment <NUM> extends axially along the axial centerline <NUM> between an attachment first (e.g., forward and/or upstream) axial side <NUM> and an attachment second (e.g., aft and/or downstream) axial side <NUM>. As best seen in <FIG>, the mount attachment <NUM> extends laterally between opposing attachment lateral sides <NUM> and <NUM>.

The mount attachment <NUM> includes one or more attachment pressure surfaces <NUM> and <NUM> (e.g., engagement surfaces) and a bottom surface <NUM>. The first attachment pressure surface <NUM> is arranged to the first lateral side <NUM> of the mount attachment <NUM> and the second attachment pressure surface <NUM> is arranged to the second lateral side <NUM> of the mount attachment <NUM>. The first and the second attachment pressure surfaces <NUM> and <NUM> may meet (e.g., be joined) at an outer peak of the mount attachment <NUM>. The first and the second attachment pressure surfaces <NUM> and <NUM> may also respectively meet the neck lateral sides <NUM> and <NUM> at interfaces between the mount attachment <NUM> and the mount neck <NUM>; see also <FIG>.

Each of the attachment pressure surfaces <NUM>, <NUM> of <FIG> and <FIG> is a substantially planar surface. However, in other embodiments, the first attachment pressure surface <NUM> and/or the second attachment pressure surface <NUM> may have a non-planar (e.g., curved and/or compound angled) geometry. Referring to <FIG>, the attachment pressure surfaces <NUM>, <NUM> are angularly offset from one another by an included angle <NUM>. This angle <NUM> may be greater than sixty degrees (<NUM>°) and less than one hundred and forty degrees (<NUM>°). The present invention, however, is not limited to such exemplary angles. Furthermore, while an angle <NUM> between the attachment surface <NUM> and a span-line <NUM> of the rotor blade <NUM> and an angle <NUM> between the attachment surface <NUM> and the span-line <NUM> are shown as equal in <FIG> (e.g., the mount attachment <NUM> may be a symmetric attachment), the angle <NUM> may alternatively be different (e.g., greater or less) than the angle <NUM> (e.g., the mount attachment <NUM> may be an asymmetric attachment) in other embodiments.

The bottom surface <NUM> of <FIG> extends laterally between respective radial inner ends of the attachment pressure surfaces <NUM> and <NUM>. The first attachment pressure surface <NUM> extends radially between the bottom surface <NUM> and the first neck lateral side <NUM>. The second attachment pressure surface <NUM> extends radially between the bottom surface <NUM> and the second neck lateral side <NUM>.

Referring to <FIG>, an axial first end portion <NUM> (e.g., a cantilevered projection) of the mount attachment <NUM> projects axially out from the neck first side <NUM>. The rotor blade mount <NUM> is thereby configured with a first gap <NUM> (e.g., a recess, a notch, etc.) axially adjacent the mount neck <NUM>, which first gap <NUM> extends radially between the axial first end portion <NUM> of the mount attachment <NUM> and the mount platform <NUM>. Similarly, an axial second end portion <NUM> (e.g., a cantilevered projection) of the mount attachment <NUM> projects axially out from the neck second side <NUM>. The rotor blade mount <NUM> is thereby configured with a second gap <NUM> (e.g., a recess, a notch, etc.) axially adjacent the mount neck <NUM>, which second gap <NUM> extends radially between the axial second end portion <NUM> of the mount attachment <NUM> and the mount platform <NUM>.

Referring to <FIG> and <FIG>, the rotor blade airfoil <NUM> is connected (e.g., directly) to the mount platform <NUM>. The rotor blade airfoil <NUM> projects radially relative to the axial centerline <NUM> out from the gas path surface <NUM>, in a spanwise direction, to a (e.g.,. unshrouded) tip <NUM> of the rotor blade airfoil <NUM>.

Referring to <FIG>, the rotor blade airfoil <NUM> includes a first (e.g., pressure and/or concave) side surface <NUM>, a second (e.g., suction and/or convex) side surface <NUM>, a (e.g., forward and/or upstream) leading edge <NUM> and a (e.g., aft and/or downstream) trailing edge <NUM>. The first and second side surfaces <NUM> and <NUM> extends along a chord line of the rotor blade airfoil <NUM> between and meet at the leading edge <NUM> and the trailing edge <NUM>.

The rotor blade <NUM> and its various components <NUM> and <NUM> of <FIG> may be configured together as a monolithic body. The term "monolithic" may describe a single unitary body formed without severable components; e.g., a body formed with integral components. For example, the rotor blade <NUM> may be laid up, cast, machined and/or otherwise formed from a single body of material. In another example, the rotor blade <NUM> may be formed from a plurality of discretely formed segments which are subsequently permanently bonded together; e.g., welded, adhered, etc. Examples of permanent bonding techniques include, but are not limited to, transient liquid phase (TLP) bonding of one or more components to form a single unitized structure blade pair. These components may be single crystal or poly-crystalline or directionally controlled crystalline structures that are individually oriented in an optimized manner to provide locally desired structural capability. By contrast, the term "non-monolithic" may described a body formed from a plurality of discretely formed bodies that are severable; e.g., may be disassembled from one another. For example, a non-monolithic body may be formed from a plurality of discretely formed segments which are subsequently mechanically attached and/or brazed together. The present invention, however, is not limited to monolithic rotor blades <NUM>.

The rotor blade <NUM> and its various components <NUM> and <NUM> may be formed from various metallic or non-metallic materials. Examples of the rotor blade materials include, but are not limited to, metal, intermetallic material and/or ceramic. Examples of the metal include, but are not limited to, nickel (Ni), titanium (Ti), aluminum (Al), chromium (Cr) or an alloy of one or more of the foregoing metals; e.g., a single crystal alloy or super alloy. Examples of the intermetallic material include, but are not limited to, TiAl and NiAl. The ceramic may be a monolithic ceramic or a ceramic matrix composite (CMC) material. An example of the monolithic ceramic is, but is not limited to, Si<NUM>N<NUM>. Examples of the ceramic matrix composite material include, but are not limited to, SiC/SiC and C/SiC. In the case of the ceramic matrix composite material, a fiber reinforcement (e.g., long fibers or woven fibers) within a matrix of the CMC material may be laid to follow at least partially or completely along a longitudinal length of the rotor blade <NUM>. With such an arrangement, the fiber reinforcement may substantially remain in tension during operation of the rotor assembly <NUM>. The present invention, however, is not limited to such an exemplary fiber reinforcement orientation, nor to the foregoing exemplary materials. In the embodiment shown in <FIG> and <FIG>, the rotor blade <NUM> is configured as a solid rotor blade. However, in other embodiments, one or more elements including the airfoil <NUM> and/or one or more elements of the mount <NUM> (e.g., <NUM>, <NUM> and/or <NUM>) may be hollow in order to reduce the mass of the rotor blade <NUM>. The rotor blade <NUM> may also or alternatively be hollow to provide one or more flow passages for cooling the airfoil <NUM> and/or the gas path surface <NUM> of the mount platform <NUM> as described below in further detail.

Referring to <FIG>, the rotor disk assembly <NUM> includes a plurality of rotor disks such as a first (e.g., upstream / forward) rotor disk 180A and a second (e.g., downstream / aft) rotor disk 180B. Each rotor disk 180A, 180B (generally referred to as "<NUM>") extends circumferentially about (e.g., complete around) the axial centerline <NUM> to provide that rotor disk <NUM> with a full hoop, annular body. This annular body may be a monolithic body. Alternatively, the annular body may be formed from a plurality of interconnected arcuate circumferential segments; e.g., disk halves, disk thirds, disk quarters, etc..

The first rotor disk 180A of <FIG> and <FIG> includes an inner first hub 182A, a first web 184A and an outer first rim 186A. The first rotor disk 180A of <FIG> also includes one or more first disk mounts 188A; see also <FIG>.

The first hub 182A is an annular segment of the first rotor disk 180A and defines an inner bore 190A through the first rotor disk 180A. The first hub 182A may be configured as a rotating mass for the first rotor disk 180A. The first web 184A is connected to and extends radially between the first hub 182A and the first rim 186A. The first rim 186A is arranged at an outer distal end 192A of the first rotor disk 180A.

In general, the first rim 186A has an (e.g., maximum) axial width that is greater than an (e.g., maximum) axial width of the first web 184A. The axial width of the first rim 186A is less than an (e.g., maximum) axial width of the first hub 182A, where the axial width of the first hub 182A is also greater than the axial width of the first web 184A. The present invention, however, is not limited to the foregoing exemplary relationships. For example, in other embodiments, the axial width of the first rim 186A may be equal to the axial width of first hub 182A.

Referring to <FIG>, the first web 184A is configured with one or more first disk mount apertures 194A (e.g., through-holes). These first disk mount apertures 194A may be radially intermediately located between the first hub 182A and the first rim 186A. Note, the first disk mount 188A in <FIG> is shown out of plane for reference in order to illustrate the relative positioning of aperture first disk mount apertures 194A.

Referring to <FIG>, the first disk mount apertures 194A are arranged circumferentially around the axial centerline <NUM> in an annular array and are interposed with the first disk mounts 188A. For example, a respective one of the first disk mounts 188A may be positioned circumferentially between each circumferentially adjacent / neighboring pair of the first disk mount apertures 194A. Similarly, a respective one of the first disk mount apertures 194A may be positioned circumferentially between each circumferentially adjacent / neighboring pair of the first disk mounts 188A. Each of these first disk mount apertures 194A of <FIG> has a circular cross-sectional geometry. However, in other embodiments, one or more or each of the first disk mount apertures 194A may have a non-circular geometry (e.g., an elliptical cross-sectional geometry, a polygonal (e.g., rectilinear) cross-sectional geometry, etc.) or any other geometry selected to accommodate a respective one of the disk mounts 188B as described below.

Referring to <FIG>, the first rim 186A is configured with one or more first disk pockets 196A located at (e.g., on, adjacent or proximate) an outer end of the first rim 186A. These first disk pockets 196A are arranged circumferentially around the axial centerline <NUM> in an annular array. The first disk pockets 196A of <FIG> are circumferentially interconnected so as to form an (e.g., serrated) annular groove 198A in the first rim 186A. However, in other embodiments, the first disk pockets 196A may be discrete from one another and separated by divider portions 200A of the first rim 186A as shown, for example, in <FIG>.

Referring to <FIG>, each of the first disk pockets 196A projects axially along the axial centerline <NUM> partially into first rim 186A from an axial interior side 202A of the first rotor disk 180A to a first disk pocket end surface 204A. Referring to <FIG>, each of the first disk pockets 196A extends radially within the first rim 186A from a first disk pocket inner (e.g., bottom) surface 206A to a pair of first disk pressure surfaces 208A and 210A. Each of the first disk pockets 196A extends laterally within the first rim 186A between the pair of first disk pressure surfaces 208A and 210A as well as between circumferentially neighboring first disk pockets 196A.

The first disk pocket end surface 204A extends radially between the first disk pocket inner surface 206A and the pair of first disk pressure surfaces 208A and 210A. The first disk pocket end surface 204A extends laterally between the pair of first disk pressure surfaces 208A and 210A. In the embodiment of <FIG>, the first disk pocket end surface 204A also extends laterally between pressure surfaces 208A, 210A of circumferentially neighboring first disk pockets 196A. The first disk pocket end surface 204A thereby may axially enclose an axial end of a respect first disk pocket 196A; see <FIG>.

The first disk pressure surface 208A is arranged to a first lateral side of the first disk pocket 196A and the first disk pressure surface 210A is arranged to a second lateral side of the first disk pocket 196A. The first disk pressure surfaces 208A and 210A may meet (e.g., be joined) at an outer peak 212A of the first disk pocket 196A. The first disk pressure surfaces 208A and 210A may thereby radially enclose the respective first disk pocket 196A within the first rim 186A.

Each of the first disk pressure surfaces 208A and 210A of <FIG> is a substantially planar surface. However, in other embodiments, the first disk pressure surface 208A and/or the first disk pressure surface 208B may have a non-planar (e.g., curved and/or compound angled) geometry. The first disk pressure surfaces 208A and 210A are angularly offset from one another by an included angle 214A. This angle 214A may be greater than sixty degrees (<NUM>°) and less than one hundred and forty degrees (<NUM>°). The present invention, however, is not limited to such exemplary angles. In general, the disk pressure surfaces 208A and 210A are configured to compliment the attachment pressure surfaces <NUM> and <NUM> to facilitate engagement between the mount attachments <NUM> and the first rotor disk 180A as described below in further detail; however, such a correspondence is not required. Furthermore, while an angle 215A between the first disk pressure surface 208A and a ray 217A from the centerline <NUM> and an angle 219A between the first disk pressure surface 210A and the ray 217A are shown as equal in <FIG> (e.g., the first disk pocket 196A may be a symmetric first disk pocket), the angle 215A may alternatively be different (e.g., greater or less) than the angle 219A (e.g., the first disk pocket 196A may be an asymmetric first disk pocket) in other embodiments.

Referring to <FIG> and <FIG>, the first disk mounts 188A are arranged circumferentially around the axial centerline <NUM> in an annular array and are interposed with the first disk mount apertures 194A as described above. The first disk mounts 188A are radially aligned with the first disk mount apertures 194A; see also <FIG>. Each first disk mount 188A of <FIG> is connected to (e.g., formed integral with) the first web 184A. Each first disk mount 188A projects axially out from and is cantilevered from the first web 184A in a first axial direction (e.g., an aft / downstream direction) to a distal first disk mount end 216A. Each first disk mount 188A may be configured with a first mount slot 218A proximate the first disk mount end 216A. This first mount slot 218A extends axially within the first disk mount 188A. The first mount slot 218A extends circumferentially through the first disk mount 188A. The first mount slot 218A extends radially outward and partially into the first disk mount 188A to a first slot end surface.

The second rotor disk 180B of <FIG> and <FIG> includes an inner second hub 182B, a second web 184B and an outer second rim 186B. The second rotor disk 180B of <FIG> also includes one or more second disk mounts 188B; see also <FIG>.

The second hub 182B is an annular segment of the second rotor disk 180B and defines an inner bore 190B through the second rotor disk 180B. The second hub 182B may be configured as a rotating mass for the second rotor disk 180B. The second web 184B is connected to and extends radially between the second hub 182B and the second rim 186B. The second rim 186B is arranged at an outer distal end 192B of the second rotor disk 180B.

In general, the second rim 186B has an (e.g., maximum) axial width that is greater than an (e.g., maximum) axial width of the second web 184B. The axial width of the second rim 186B is less than an (e.g., maximum) axial width of the second hub 182B, where the axial width of the second hub 182B is also greater than the axial width of the second web 184B. The present invention, however, is not limited to the foregoing exemplary relationships. For example, in other embodiments, the axial width of the second rim 186B may be equal to the axial width of second hub 182B.

Referring to <FIG>, the second web 184B is configured with one or more second disk mount apertures 194B (e.g., through-holes). These second disk mount apertures 194B may be radially intermediately located between the second hub 182B and the second rim 186B. Note, the second disk mount 188B in <FIG> is shown out of plane for reference in order to illustrate the relative positioning of aperture second disk mount apertures 194B.

Referring to <FIG>, the second disk mount apertures 194B are arranged circumferentially around the axial centerline <NUM> in an annular array and are interposed with the second disk mounts 188B. For example, a respective one of the second disk mounts 188B may be positioned circumferentially between each circumferentially adjacent / neighboring pair of the second disk mount apertures 194B. Similarly, a respective one of the second disk mount apertures 194B may be positioned circumferentially between each circumferentially adjacent / neighboring pair of the second disk mounts 188B. Each of these second disk mount apertures 194B of <FIG> has a circular cross-sectional geometry. However, in other embodiments, one or more or each of the second disk mount apertures 194B may have a non-circular geometry (e.g., an elliptical cross-sectional geometry, a polygonal (e.g., rectilinear) cross-sectional geometry, etc.) or any other geometry selected to accommodate a respective one of the disk mounts 188A as described below.

Referring to <FIG>, the second rim 186B is configured with one or more second disk pockets 196B located at (e.g., on, adjacent or proximate) an outer end of the second rim 186B. These second disk pockets 196B are arranged circumferentially around the axial centerline <NUM> in an annular array. The second disk pockets 196B of <FIG> are circumferentially interconnected so as to form an annular groove 198B in the second rim 186B.

However, in other embodiments, the second disk pockets 196B may be discrete from one another and separated by divider portions 200B of the second rim 186B as shown, for example, in <FIG>.

Referring to <FIG>, each of the second disk pockets 196B projects axially along the axial centerline <NUM> partially into second rim 186B from an axial interior side 202B of the second rotor disk 180B to a second disk pocket end surface 204B. Referring to <FIG>, each of the second disk pockets 196B extends radially within the second rim 186B from a second disk pocket inner (e.g., bottom) surface 206B to a pair of second disk pressure surfaces 208B and 210B. Each of the second disk pockets 196B extends laterally within the second rim 186B between the pair of second disk pressure surfaces 208B and 210B as well as between circumferentially neighboring second disk pockets 196B.

The second disk pocket end surface 204B extends radially between the second disk pocket inner surface 206B and the pair of second disk pressure surfaces 208B and 210B. The second disk pocket end surface 204B extends laterally between the pair of second disk pressure surfaces 208B and 210B. In the embodiment of <FIG>, the second disk pocket end surface 204B also extends laterally between pressure surfaces 208B, 210B of circumferentially neighboring second disk pockets 196B. The second disk pocket end surface 204B thereby may axially enclose an axial end of a respect second disk pocket 196B; see <FIG>.

The second disk pressure surface 208B is arranged to a first lateral side of the second disk pocket 196B and the second disk pressure surface 210B is arranged to a second lateral side of the second disk pocket 196B. The second disk pressure surfaces 208B and 210B may meet (e.g., be joined) at an outer peak 212B of the second disk pocket 196B. The second disk pressure surfaces 208B and 210B may thereby radially enclose the respective second disk pocket 196B within the second rim 186B.

Each of the second disk pressure surfaces 208B and 210B of <FIG> is a substantially planar surface. However, in other embodiments, the second disk pressure surface 208B and/or the second disk pressure surface 210B may have a non-planar (e.g., curved and/or compound angled) geometry. The second disk pressure surfaces 208B and 210B are angularly offset from one another by an included angle 214B. This angle 214B may be greater than sixty degrees (<NUM>°) and less than one hundred and forty degrees (<NUM>°). The present invention, however, is not limited to such exemplary angles. In general, the disk pressure surfaces 208B and 210B are configured to compliment the attachment pressure surfaces <NUM> and <NUM> to facilitate engagement between the mount attachments <NUM> and the second rotor disk 180B as described below in further detail; however, such a correspondence is not required. Furthermore, while an angle 215B between the second disk pressure surface 208B and a ray 217B from the centerline <NUM> and an angle 219B between the second disk pressure surface 210B and the ray 217B are shown as equal in <FIG> (e.g., the second disk pocket 196B may be a symmetric second disk pocket), the angle 215B may alternatively be different (e.g., greater or less) than the angle 219B (e.g., the second disk pocket 196B may be an asymmetric second disk pocket) in other embodiments.

Referring to <FIG> and <FIG>, the second disk mounts 188B are arranged circumferentially around the axial centerline <NUM> in an annular array and are interposed with the second disk mount apertures 194B as described above. The second disk mounts 188B are radially aligned with the second disk mount apertures 194B; see also <FIG>. Each second disk mount 188B of <FIG> is connected to (e.g., formed integral with) the second web 184B. Each second disk mount 188B projects axially out from and is cantilevered from the second web 184B in a second axial direction (e.g., a forward / upstream direction) to a distal second disk mount end 216B, which second axial direction is opposite the first axial direction. Each second disk mount 188B may be configured with a second mount slot 218B proximate the second disk mount end 216B. This second mount slot 218B extends axially within the second disk mount 188B. The second mount slot 218B extends circumferentially through the second disk mount 188B. The second mount slot 218B extends radially outward and partially into the second disk mount 188B to a second slot end surface.

Each rotor disks <NUM> and its various components may be configured as a monolithic body. The present invention, however, is not limited to such an exemplary configuration. For example, in other embodiments, the disk mounts 188A, 188B (generally referred to as "<NUM>") may be discrete from (e.g., removable from) each of the rotor disks <NUM> as described below in further detail.

Each of the rotor disks <NUM> may be configured from any suitable material such as, but not limited to, metal. Examples of the metal include, but are not limited to, nickel (Ni), titanium (Ti), aluminum (Al), chromium (Cr) or an alloy of one or more of the foregoing metals; e.g., a single crystal alloy or super alloy. The present invention, however, is not limited to the foregoing exemplary rotor disk materials, or metal in general. Referring to <FIG>, one or each of the rotor disks <NUM> also include one or more reinforcing rings <NUM>. These reinforcing ring(s) <NUM> are configured to assist the respective rotor disks <NUM> in carrying loads induced by rotation of the disk <NUM> and rotor assembly <NUM>. These reinforcing ring(s) <NUM> may be integral with one or more disk elements (e.g., bonded into a pocket <NUM>, <NUM> in or on the disk <NUM>, bonded to a flange <NUM> on the disk <NUM>) or mechanically attached with disk element(s). Each reinforcing ring <NUM> may be located within a respective rotor disk <NUM> (e.g., within the internal pocket <NUM>; see <FIG>), axially between the rotor disks <NUM> (e.g., in the pocket <NUM> and trapped between the webs <NUM>; see <FIG>) and/or on an outer surface of a respective rotor disk <NUM> (e.g., on the flange <NUM>; see <FIG>). Each reinforcing ring <NUM> may be configured as a segmented or unsegmented full hoop body. Each reinforcing ring <NUM> may be configured from and/or only include monolithic materials including metallic alloys, laminated or layered materials with two or more materials, or composite materials including metal matrix composite, ceramic matrix composites or organic matric composites. Furthermore, in some embodiments, the rotor assembly <NUM> may be configured with both internal and external reinforcing rings <NUM>; e.g., any combination of the rings <NUM> of <FIG>.

Referring to <FIG> and <FIG>, the rotor blades <NUM> are mated with the first rotor disk 180A and the second rotor disk 180B. The rotor blades <NUM>, for example, are arranged circumferentially around the axial centerline <NUM> in an annular array, and captured between and mounted to the first rim 186A and the second rim 186B.

The axial first end portion <NUM> of each mount attachment <NUM> is mated with a respective one of the first disk pockets 196A. In particular, the axial first end portion <NUM> of each mount attachment <NUM> projects axially (in the second axial direction) into the respective first disk pocket 196A. The attachment first axial side <NUM> is axially adjacent and may be abutted against (e.g., contact or otherwise engage) the first disk pocket end surface 204A. A portion of the first rotor disk 180A thereby extends laterally across and thereby laterally covers the respective mount attachment <NUM> and its axial first end portion <NUM>.

Referring to <FIG>, the attachment pressure surface <NUM> is arranged adjacent and configured to engage (e.g., contact) the first disk pressure surface 208A. Similarly, the attachment pressure surface <NUM> is arranged adjacent and configured to engage the first disk pressure surface 210A. As best seen in <FIG>, a portion 220A of the first rotor disk 180A projects axially into the first gap <NUM>. The first disk portion 220A is thereby disposed radially between the axial first end portion <NUM> of the respective mount attachment <NUM> and the respective mount platform <NUM>; see also <FIG>.

With the foregoing interface between the first rotor disk 180A and the rotor blades <NUM>, the first rotor disk 180A may substantially (e.g., completely) radially and circumferentially cover the mount attachments <NUM> and the mount necks <NUM>. This configuration reduces fluid leakage paths across the first rotor disk 180A and, thus, may eliminate or significantly reduce the need for additional sealing devices such as, but not limited to, a rotor disk cover plate for covering attachment slots.

Referring to <FIG> and <FIG>, the axial second end portion <NUM> of each mount attachment <NUM> is mated with a respective one of the second disk pockets 196B. In particular, the axial second end portion <NUM> of each mount attachment <NUM> projects axially (in the first axial direction) into the respective second disk pocket 196B. The attachment second axial side <NUM> is axially adjacent and may be abutted against (e.g., contact or otherwise engage) the second disk pocket end surface 204B. A portion of the second rotor disk 180B thereby extends laterally across and thereby laterally covers the respective mount attachment <NUM> and its axial second end portion <NUM>.

Referring to <FIG>, the attachment pressure surface <NUM> is arranged adjacent and configured to engage (e.g., contact) the second disk pressure surface 208B. Similarly, the attachment pressure surface <NUM> is arranged adjacent and configured to engage the second disk pressure surface 210B. As best seen in <FIG>, a portion 220B of the second rotor disk 180B projects axially into the second gap <NUM>. The second disk portion 220B is thereby disposed radially between the axial second end portion <NUM> of the respective mount attachment <NUM> and the respective mount platform <NUM>; see also <FIG>.

With the foregoing interface between the second rotor disk 180B and the rotor blades <NUM>, the second rotor disk 180B may substantially (e.g., completely) radially and circumferentially cover the mount attachments <NUM> and the mount necks <NUM>. This configuration reduces fluid leakage paths across the second rotor disk 180B and, thus, may eliminate or significantly reduce the need for additional sealing devices such as, but not limited to, a rotor disk cover plate for covering attachment slots.

Referring to <FIG> and <FIG>, the first rotor disk 180A and the second rotor disk 180B are mated together. Each of the first disk mounts 188A, for example, may be aligned with a respective one of the second disk mount apertures 194B; see <FIG>. Each of the second disk mounts 188B may be aligned with a respective one of the first disk mount apertures 194A; see <FIG>. The first rotor disk 180A and the second rotor disk 180B may then be moved (e.g., translated) axially towards one another such that (A) the first disk mounts 188A respectively project axially through the second disk mount apertures 194B and (B) the second disk mounts 188B respectively project axially through the first disk mount apertures 194A. A first retention element 222A (e.g., a retention ring such as, but not limited to, a split ring) is mated with / seated in the slots 218A in the first disk mounts 188A (see <FIG>) as well as associated slots 224A in the second rim 186B (see <FIG>). Similarly, a second retention element 222B (e.g., a retention ring such as, but not limited to, a split ring) is mated with / seated in the slots 218B in the second disk mounts 188B (see <FIG>) as well as associated slots 224B in the first rim 186A (see <FIG>). The first disk mounts 188A and the second disk mounts 188B thereby connect the first rotor disk 180A and the second rotor disk 180B together.

In some embodiments, the second disk mounts 188B may be configured with the first rotor disk 180A such that all of the disk mounts are connected to (e.g., integral with) and project out from the first rotor disk 180A; e.g., similar to as shown in <FIG>. In such embodiments, the second rotor disk 180B may be configured without any integral disk mounts (e.g., 188B) and may just include the second disk mount apertures 194B. Alternatively, the first disk mounts 188A may be configured with the second rotor disk 180B such that all of the disk mounts are connected to (e.g., integral with) and project out from the second rotor disk 180B; e.g., similar to as shown in <FIG>. In such embodiments, the first rotor disk 180A may be configured without any integral disk mounts (e.g., 188A) and may just include the first disk mount apertures 194A.

In some embodiments, referring to <FIG>, the first disk mounts 188A and/or the second disk mounts 188B may each be formed discrete from the rotor disks <NUM>. For example, each disk mount <NUM> may alternatively be configured as a fastener such as, but not limited to, a tie rod / bolt <NUM> and a nut <NUM>. In such embodiments, each disk mount <NUM> projects axially and sequentially through respective apertures 194A and 194B in the components 180A and 180B.

In some embodiments, one or more of the rotor disks <NUM> may each include one or more (e.g., a circumferential array) of standoffs 230A and 230B (generally referred to as "<NUM>"); e.g., axial projections. These standoffs <NUM> are configured to maintain an axial gap between the first rotor disk 180A and its first web 184A and the second rotor disk 180B and its second web 184B. The standoffs <NUM>, for example, may prevent deformation of the first web 184A and the second web 184B axially towards one another when the disk mounts <NUM> are tightened and secured. In the embodiment of <FIG>, each standoff 230A is configured to axially engage (e.g., contact) a respective one of the standoffs 230B. However, in other embodiments, each standoff 230A may directly axially engage the second web 184B and each standoff 230B may directly axially engage the first web 184A. In other embodiments, the first rotor disk 180A or the second rotor disk 180B may be configured with out the standoffs <NUM>.

In some embodiments, referring to <FIG>, one or more or each of the disk mounts <NUM> may be configured with a circular cross-sectional geometry when viewed in a plane perpendicular to the axial centerline <NUM>. In some embodiments, referring to <FIG>, one or more or each of the disk mounts <NUM> may be configured with an elongated (e.g., oval, elliptical, etc.) cross-sectional geometry when viewed in a plane perpendicular to the axial centerline <NUM>. In some embodiments, referring to <FIG>, one or more or each of the disk mounts <NUM> may be configured with a polygonal (e.g., square, rectangular, triangular, etc.) cross-sectional geometry when viewed in a plane perpendicular to the axial centerline <NUM>.

In some embodiments, referring to <FIG>, one or each rotor disk rim 186A and 186B (generally referred to as "<NUM>") may be configured as a circumferentially uninterrupted annular rim of the respective rotor disk <NUM>. In other embodiments, referring to <FIG>, one or each rotor disk rim <NUM> may be configured as a circumferentially interrupted annular rim. The rotor disk rim <NUM> of <FIG>, for example, includes one or more (e.g., stress reduction) slots <NUM>. Each of these slots <NUM> extends axially through the rotor disk rim <NUM> and may be aligned with a respective one of the rotor blades <NUM> and its mount attachment <NUM>. However, the number of slots <NUM> may be selected to be less than the number of rotor blades <NUM> such that only a select number of the rotor blades <NUM> is aligned with a slot <NUM>. For example, every other rotor blade <NUM> / mount attachment <NUM> may be aligned with (e.g., radially and circumferentially overlapped by) one of the slots <NUM> such that the other mount attachments <NUM> are completely covered by the rotor disk <NUM> to reduce fluid leakage thereacross. The present invention, however, is not limited to the foregoing exemplary ratio between rotor blades <NUM> and slots <NUM>. For example, in other embodiments, there could be a <NUM>:<NUM>, <NUM>:<NUM>, etc. ratio between the rotor blades <NUM> and the slots <NUM>.

In some embodiments, referring to <FIG> and <FIG>, the rotor assembly <NUM> may be configured with one or more internal vanes <NUM>; e.g., fluid pumping vanes. These internal vanes <NUM> are configured to direct fluid (e.g., gas such as air) radially through the rotor disk assembly <NUM>. The internal vanes <NUM> of <FIG> and <FIG>, for example, are configured to pump (e.g., flow and pressurize) the fluid (e.g., cooling air) received from one or both of the bores 190A and 190B (generally referred to as "<NUM>") radially, in a radial outward direction, through the rotor disk assembly <NUM> towards (e.g., to) the rotor blades <NUM>. The fluid may thereby cool the rotor disk assembly <NUM> and its rotor disks <NUM>. The fluid may then enter internal cooling passages in the rotor blades <NUM> (see exemplary passage <NUM> in <FIG>) for cooling the rotor blades <NUM>.

Referring to <FIG>, each of the internal vanes <NUM> is arranged within an annulus <NUM> (e.g., an annular plenum, passage) axially between the first web 184A and the second web 184B. Each of the internal vanes <NUM> extends longitudinally (e.g., generally radially) along a centerline <NUM> of that vane <NUM> from a radial inner end <NUM> of that vane <NUM> to a radial outer end <NUM> of that vane <NUM>. Each of the internal vanes <NUM> extends axially between a vane first side <NUM> and a vane second side <NUM>. The vane first side <NUM> is located at a side of the first web 184A and the vane second side <NUM> is located at a side of the second web 184B. For example, each of the internal vanes <NUM> may be connected to (e.g., formed integral with) the first web 184A and may project axially out to its vane second side <NUM>, where the second side <NUM> may axially contact or otherwise engage the second web 184B. In another example, each of the internal vanes <NUM> may be connected to (e.g., formed integral with) the second web 184B and may project axially out to its vane first side <NUM>, where the first side <NUM> may axially contact or otherwise engage the first web 184A. In still another example, some of the internal vanes <NUM> may be connected to the first web 184A and may axially engage the second web 184B, and the remaining internal vanes <NUM> may be connected to the second web 184B and may axially engage the first web 184A. In such embodiments, the vanes <NUM> connected to the first web 184A may be interposed with the vanes <NUM> connected to the second web 184B.

Referring to <FIG>, the internal vanes <NUM> are arranged circumferentially around the axial centerline <NUM> in an annular array. A circumferential distance between circumferentially neighboring internal vanes <NUM> may increase as those vanes extend radially outward away from the axial centerline <NUM>.

In the specific embodiment of <FIG>, the internal vanes <NUM> are interposed with the disk mounts <NUM>. For example, a respective one of the disk mounts <NUM> may be located circumferentially between each circumferentially neighboring pair of the internal vanes <NUM>. Similarly, a respective one of the internal vanes <NUM> may be located circumferentially between each circumferentially neighboring pair of the disk mounts <NUM>. Of course, in other embodiments, more than one internal vane <NUM> may be located circumferentially between one or more or each circumferentially neighboring pair of the disk mounts <NUM>, or vice versa. Furthermore, while the internal vanes <NUM> radially overlap circumferentially neighboring disk mounts <NUM> in <FIG>, the internal vanes <NUM> may be positioned radially outward and/or inward of the circumferentially neighboring disk mounts <NUM> in other embodiments.

One or more or each of the internal vanes <NUM> may be formed integral with a respective one of the rotor disks <NUM> as described above. For example, the rotor disk <NUM> and the respective internal vanes <NUM> may be formed together from a single mass of material. Alternatively, the internal vanes <NUM> may be permanently bonded to the rotor disk <NUM> using one or more of the techniques described above, for example. However, in other embodiments, one or more of the internal vanes <NUM> may be removably mounted to the rotor disk assembly <NUM>. For example, referring to <FIG> and <FIG>, the internal vanes <NUM> may be configured into a plurality of tubular structures <NUM> that are removably attached to one or each of the rotor disks <NUM>.

Referring to <FIG>, each tubular structure <NUM> includes a circumferentially neighboring pair of the internal vanes <NUM>. Each tubular structure <NUM> also includes a first sidewall <NUM> and a second sidewall <NUM>. The first sidewall <NUM> is disposed at an axial first side of the tubular structure <NUM>, and extends laterally between and is connected to the internal vanes <NUM>. The second sidewall <NUM> is disposed at an axial second side of the tubular structure <NUM>, and extends laterally between and is connected the internal vanes <NUM>. Each tubular structure <NUM> is thereby configured with an internal passage <NUM> which is fluidly coupled with the passage(s) <NUM> in a respective one (or more) of the rotor blades <NUM>; see <FIG>.

Referring to <FIG>, the tubular structures <NUM> are arranged circumferentially about the axial centerline <NUM> in an annular array. Circumferentially neighboring tubular structures <NUM> may be circumferentially spaced from one another so as to form exterior passages <NUM> therebetween, where each exterior passage <NUM> is fluidly coupled with the passage(s) <NUM> in a respective one (or more) of the rotor blades <NUM>; see <FIG>.

In the specific embodiment of <FIG>, the internal vanes <NUM> are interposed with the disk mounts <NUM> in a similar fashion as described above. With this configuration, a respective one of the disk mounts <NUM> may be located circumferentially between each circumferentially neighboring pair of the tubular structures <NUM>. In addition, a respective one of the disk mounts <NUM> may project axially through the first sidewall <NUM> and the second sidewall <NUM> of each tubular structure <NUM>. Of course, in other embodiments, the disk mounts <NUM> may only be positioned in the gap between neighboring tubular structures <NUM>. In still other embodiments, the disk mounts <NUM> may only be aligned with and, thus, project axially through the tubular structures <NUM>.

Referring to <FIG>, the axial first side and the first sidewall <NUM> of the tubular structure <NUM> is located at (e.g., abutted axially against or otherwise axially engaged with) the first web 184A. The axial second side and the second sidewall <NUM> of the tubular structure <NUM> is located at (e.g., abutted axially against or otherwise axially engaged with) the second web 184B.

Referring to <FIG>, the axial first side may be mounted to the first rotor disk 180A and the axial second side may be mounted to the second rotor disk 180B. Each tubular structure <NUM>, for example, may include a first mount <NUM> and a second mount <NUM>. The first mount <NUM> of <FIG> is configured as a (e.g., cantilevered) first flange located at a distal radial outer end of the tubular structure <NUM>. This first flange projects axially (in the second axial direction) into a first groove <NUM> in the first rotor disk 180A; e.g., in the first web 184A. The second mount <NUM> of <FIG> is configured as a (e.g., cantilevered) second flange located at the distal radial outer end of the tubular structure <NUM>. This second flange projects axially (in the first axial direction) into a second groove <NUM> in the second rotor disk 180B; e.g., in the second web 184B.

Referring to <FIG>, at least a portion (or an entirety) of each internal vane <NUM> and its centerline <NUM> may be straight. The internal vane <NUM> and the centerline <NUM> of <FIG>, for example, is straight as those elements <NUM>, <NUM> extend longitudinally between the radial inner end <NUM> and the radial outer end <NUM>. At least a portion (or an entirety) of the internal vane <NUM> and the centerline <NUM> may also (or alternatively) be perpendicular to the axial centerline <NUM> when viewed, for example, in a plane perpendicular to the axial centerline <NUM>. However, referring now to <FIG>, at least a portion (or an entirety) of each internal vane <NUM> and its centerline <NUM> may be non-straight; e.g., curved, include angled segments, etc. The internal vane <NUM> and the centerline <NUM> of <FIG>, for example, is curved (e.g., follows a spline, an elliptical or a circular geometry, etc.) as those elements <NUM>, <NUM> extend longitudinally between the radial inner end <NUM> and the radial outer end <NUM>. At least a portion (or an entirety) of the internal vane <NUM> and the centerline <NUM> may also (or alternatively) be non-perpendicular to (e.g., angularly offset from) the axial centerline <NUM> when viewed, for example, in a plane perpendicular to the axial centerline <NUM>. The internal vanes <NUM> of the present invention, of course, are not limited to the foregoing exemplary sectional geometries.

Each of the internal vanes <NUM> (e.g., see <FIG>) as well as each of the tubular structures <NUM> and its various components (e.g., see <FIG>) is formed from vane material. This vane material may be the same as the rotor disk material, particularly where the internal vane(s) <NUM> are formed integral with the rotor disk(s) <NUM>. Alternatively, the vane material may be different than the rotor disk material. For example, whereas the rotor disks <NUM> may be formed from metal, the internal vanes <NUM> / the tubular structures <NUM> may be formed from non-metallic materials. The internal vanes <NUM> / the tubular structures <NUM>, for example, may be formed from a ceramic such as, but not limited to, a ceramic matrix composite (CMC) material. The elements <NUM>, <NUM> may thereby me formed as light-weight and/or heat resistant components. The present invention, however, is not limited to the foregoing exemplary vane materials.

<FIG> is a side cutaway illustration of a geared turbine engine <NUM> with which the rotor assembly <NUM> may be included. This turbine engine <NUM> extends along the axial centerline <NUM> between an upstream airflow inlet <NUM> and a downstream airflow exhaust <NUM>. The turbine engine <NUM> includes a fan section <NUM>, a compressor section <NUM>, a combustor section <NUM> and a turbine section <NUM>. The compressor section <NUM> includes a low pressure compressor (LPC) section 275A and a high pressure compressor (HPC) section 275B. The turbine section <NUM> includes a high pressure turbine (HPT) section 277A and a low pressure turbine (LPT) section 277B.

The engine sections <NUM>-<NUM> are arranged sequentially along the axial centerline <NUM> within an engine housing <NUM>. This engine housing <NUM> includes an inner case <NUM> (e.g., a core case) and an outer case <NUM> (e.g., a fan case). The inner case <NUM> may house one or more of the engine sections 275A-277B; e.g., an engine core. The outer case <NUM> may house at least the fan section <NUM>.

Each of the engine sections <NUM>, 275A, 275B, 277A and 277B includes a respective rotor <NUM>-<NUM>, any one of which may be configured as or may include the rotor assembly <NUM> of <FIG>. The rotor assembly <NUM>, for example, may be included in one of the turbine rotors <NUM> and <NUM>. Each of the rotors <NUM>-<NUM> of <FIG> includes a plurality of rotor blades arranged circumferentially around and connected to one or more respective rotor disks. The rotor blades, for example, may be formed integral with or mechanically fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor disk(s).

The fan rotor <NUM> is connected to a gear train <NUM>, for example, through a fan shaft <NUM>. The gear train <NUM> and the LPC rotor <NUM> are connected to and driven by the LPT rotor <NUM> through a low speed shaft <NUM>. The HPC rotor <NUM> is connected to and driven by the HPT rotor <NUM> through a high speed shaft <NUM>. The shafts <NUM>-<NUM> are rotatably supported by a plurality of bearings <NUM>; e.g., rolling element and/or thrust bearings. Each of these bearings <NUM> is connected to the engine housing <NUM> by at least one stationary structure such as, for example, an annular support strut.

During operation, air enters the turbine engine <NUM> through the airflow inlet <NUM>. This air is directed through the fan section <NUM> and into a core gas path <NUM> (e.g., the gas path <NUM> in <FIG> and <FIG>) and a bypass gas path <NUM>. The core gas path <NUM> extends sequentially through the engine sections 275A-277B. The air within the core gas path <NUM> may be referred to as "core air". The bypass gas path <NUM> extends through a bypass duct, which bypasses the engine core. The air within the bypass gas path <NUM> may be referred to as "bypass air".

The turbine engine <NUM> of the present invention, however, is not limited to the foregoing exemplary thrust ratio.

The rotor assembly <NUM> and its components may be included in various turbine engines other than the one described above as well as in other types of rotational equipment. The rotor assembly <NUM> and its components, for example, may be included in a geared turbine engine where a gear train connects one or more shafts to one or more rotors in a fan section, a compressor section and/or any other engine section. Alternatively, the rotor assembly <NUM> and its components may be included in a turbine engine configured without a gear train. The rotor assembly <NUM> and its components may be included in a geared or non-geared turbine engine configured with a single spool, with two spools (e.g., see <FIG>), or with more than two spools. The turbine engine may be configured as a turbofan engine, a turbojet engine, a propfan engine, a pusher fan engine or any other type of turbine engine. The present invention therefore is not limited to any particular types or configurations of turbine engines or rotational equipment.

<FIG> is a flow diagram of a method <NUM> for manufacturing a rotor blade. For ease of description, this method <NUM> is described below with reference to forming one of the rotor blades <NUM> described above. The method <NUM>, however, is not limited to forming a rotor blade with the exemplary configurations described above with respect to the rotor blades <NUM>.

In step <NUM>, an attachment preform <NUM> is provided. An exemplary embodiment of the attachment preform <NUM> is illustrated in <FIG>. This attachment preform <NUM> has a tubular body <NUM>; e.g., a tubular outer shell. This tubular body <NUM> may be formed from one or more layers of material (e.g., see layers in <FIG>), or may be configured from a three dimensional (3D) braided structure where fibers also extend through the thickness of the shell. The tubular body <NUM> may be hollow or filled with filler material <NUM>. The filler material <NUM> may include a range of materials, examples of which may include, but are not limited to, chopped fibers, metallic or nonmetallic foam, and/or solid material. The attachment preform <NUM> is configured to form a base of the mount attachment <NUM>; e.g., see <FIG> and <FIG>. The attachment preform <NUM> of <FIG>, for example, is configured with a flared (e.g., tapered, delta-shaped, triangular, etc.) cross-sectional geometry or otherwise dovetailed shaped cross-sectional geometry when viewed, for example, in a plane perpendicular to the axial centerline <NUM>; e.g., plane of <FIG>. Referring to <FIG>, this cross-sectional geometry (or variations thereto) may extend axially along an entire (or partial) length <NUM> of the attachment preform <NUM>. The attachment preform length <NUM> may be between, for example, seventy percent (<NUM>%) and one-hundred percent (<NUM>%) of a length <NUM> of the mount attachment <NUM>. The attachment preform length <NUM>, for example, may be at least eighty, ninety or ninety-five percent of the mount attachment length <NUM>. The present invention, however, is not limited to the foregoing exemplary relationship.

In step <NUM>, one or more first sheets of material <NUM> are wrapped (e.g., substantially completely) about the attachment preform <NUM> to form (<NUM>) another portion of the rotor blade mount <NUM> (e.g., <NUM>, <NUM> and/or <NUM>) and (<NUM>) at least a portion or an entirety of the airfoil <NUM>; e.g., see <FIG>. An exemplary embodiment of one of the first sheets of material <NUM> is illustrated in <FIG>. The first sheet of material <NUM> of <FIG> extends longitudinally along a length thereof between opposing distal ends <NUM> and <NUM>. The first sheet of material <NUM> of <FIG> is wrapped about the attachment preform <NUM> such that its distal ends <NUM> and <NUM> are aligned radially outboard of the attachment preform <NUM>. Referring to <FIG>, each of the distal ends <NUM>, <NUM> may be located at (e.g., on, adjacent or proximate) and may thereby form a portion of the rotor blade tip <NUM>. Of course, in other embodiments, one or each of the distal ends <NUM>, <NUM> may be located radially inward of the rotor blade tip <NUM>. After wrapping around the attachment preform <NUM>, in one alternate embodiment, the first sheet of material <NUM> may be stitched or sewn or connected via other techniques with similar or complementary fibers in order to connect one or more surfaces or regions, for example, at the distal ends <NUM> and <NUM>. With the foregoing configuration, each first sheet of material <NUM> may thereby provide a structurally sound connection between the rotor blade airfoil <NUM> and the rotor blade mount <NUM> and its mount attachment <NUM>.

In step <NUM>, one or more second sheets of material <NUM> are wrapped about the attachment preform <NUM> and over the first sheet(s) of material <NUM> to form another portion of the rotor blade mount <NUM> (e.g., <NUM>, <NUM> and/or <NUM>); e.g., see <FIG>. The second sheets of material <NUM> may be configured from one or more layers of woven material, or one or one or more layers of braided material. An exemplary embodiment of one of the second sheets of material <NUM> is illustrated in <FIG>. The second sheet of material <NUM> of <FIG> extends longitudinally along a length thereof between opposing distal ends <NUM> and <NUM>. The second sheet of material <NUM> of <FIG> is wrapped (e.g., substantially completely or partially) about the attachment preform <NUM> such that its distal ends <NUM> and <NUM> are disposed to opposite lateral sides of the attachment preform <NUM>; however, the ends <NUM> and <NUM> may be radially aligned. Referring to <FIG>, the first distal end <NUM> may be located at the first lateral side <NUM> such that a corresponding portion of the second sheet of material <NUM> at least partially forms the lateral platform overhang <NUM>. The second distal end <NUM> may be located at the second lateral side <NUM> such that a corresponding portion of the second sheet of material <NUM> at least partially forms the lateral platform overhang <NUM>. Of course, in other embodiments, the first distal end <NUM> may be laterally recessed from the first lateral side <NUM> and/or the second distal end <NUM> may be laterally recess from the second lateral side <NUM>. After wrapping around the attachment preform <NUM> and first sheet of material <NUM>, in one alternate embodiment, the second sheet of material <NUM> may be stitched or sewn or connected via other techniques with similar or complementary fibers in order to connect one or more surfaces or regions, for example, at the distal ends <NUM> and <NUM>. In one embodiment, the location of this connection would be in the thinned region <NUM> below the platform <NUM>.

In step <NUM>, one or more third sheets of material <NUM> are layered over the second sheet(s) of material <NUM> to form another (e.g., lateral side) portion of the rotor blade mount <NUM> (e.g., <NUM>, <NUM> and/or <NUM>); e.g., see <FIG>. The third sheets of material <NUM> may be configured from one or more layers of woven material, or one or one or more layers of braided material. Exemplary embodiments of the third sheets of material <NUM> are illustrated in <FIG>. Each third sheet of material <NUM> of <FIG> extends longitudinally along a length thereof between opposing distal ends <NUM> and <NUM>, where the distal ends <NUM> and <NUM> are arranged on a common side of the attachment preform <NUM>. The first distal end <NUM> of <FIG>, for example, is configured to be aligned with (or proximate to) the platform lateral side <NUM> and/or the overhang <NUM>. The second distal end <NUM> is configured to be aligned with (e.g., overlap), or be adjacent to, the attachment pressure surface <NUM>. The third sheet(s) of material <NUM> may thereby provide a reinforced interface between the mount attachment <NUM>, the mount neck <NUM> and the mount platform <NUM> and its overhang <NUM>. After wrapping around the second sheet of material <NUM>, in one alternate embodiment, the third sheet of material <NUM> may be stitched or sewn or connected via other techniques with similar or complementary fibers in order to connect one or more surfaces or regions, for example, at the distal ends <NUM> and <NUM>. In one embodiment, the location of this connection would be in the thinned region <NUM> below the platform <NUM>.

In step <NUM>, one or more fourth sheets of material <NUM> are layered over the second sheet(s) of material <NUM> to form another (e.g., lateral side) portion of the rotor blade mount <NUM> (e.g., <NUM>, <NUM> and/or <NUM>); e.g., see <FIG>. The fourth sheets of material <NUM> may be configured from one or more layers of woven material, or one or one or more layers of braided material. Exemplary embodiments of the fourth sheets of material <NUM> are illustrated in <FIG>. Each fourth sheet of material <NUM> of <FIG> extends longitudinally along a length thereof between opposing distal ends <NUM> and <NUM>, where the distal ends <NUM> and <NUM> are arranged on a common side of the attachment preform <NUM> that is opposite the side of the third sheet(s) of material <NUM>. The first distal end <NUM> of <FIG>, for example, is configured to be aligned with (or proximate to) the platform lateral side <NUM> and/or the overhang <NUM>. The second distal end <NUM> is configured to be aligned with (e.g., overlap), or be adjacent to, the attachment pressure surface <NUM>. The fourth sheet(s) of material <NUM> may thereby provide a reinforced interface between the mount attachment <NUM>, the mount neck <NUM> and the mount platform <NUM> and its overhang <NUM>. After wrapping around the third sheet of material <NUM>, in one alternate embodiment, the fourth sheet of material <NUM> may be stitched or sewn or connected via other techniques with similar or complementary fibers in order to connect one or more surfaces or regions, for example, at the distal ends <NUM> and <NUM>. In one embodiment the location of this connection would be in the thinned region <NUM> below the platform <NUM>.

In step <NUM>, the various materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> are bonded together to form a monolithic rotor blade body. For example, where each of the various materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> are pre-impregnated / disposed within with a matrix, the matrix may be cured. Alternatively, the various materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> or some of those materials may be impregnated with / disposed within the matrix and then cured.

The method <NUM> may include additional step other than those described above. The method <NUM>, for example, may include one or more surface machining steps and/or one or more coating steps in order to provide the final rotor blade <NUM>.

The foregoing materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and any fibers used for stitching, sewing, etc. may be selected to be a common material; e.g., have the same material makeup. Alternatively, one or more of the foregoing materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and any fibers used for stitching, sewing, etc. may be different than one or more of the other materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>.

Each of the foregoing materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be configured as a woven or braded material. Some or all of the stands of the material, for example, may be woven and/or braided together to form the sheet(s) of material. Of course, in other embodiments, one or more of the layers of material may include chopped fibers as filler and/or reinforcement.

One or more or each of the foregoing materials <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be ceramic, which may be a monolithic ceramic, woven or braided material with one or more fiber types, or a ceramic matrix composite (CMC) material. An example of the monolithic ceramic is, but is not limited to, Si<NUM>N<NUM>. Examples of the ceramic matrix composite material include, but are not limited to, SiC/SiC and C/SiC. The present invention, however, is not limited to the foregoing exemplary materials compositions. The present invention is also not limited to ceramic rotor blades. For example, as described above, the rotor blades <NUM> may alternatively be formed from metal or intermetallic material. In another example, the rotor blades <NUM> may alternatively be formed from a combination of ceramic and metal. Each attachment preform <NUM> or a portion thereof (e.g., <NUM> or <NUM>), for example, may be configured from or otherwise include metal while the rest of the respective rotor blade <NUM> may be configured from or otherwise include one or more of the above-described ceramic materials, or another material different from the metal of the attachment preform <NUM> for example. In alternate embodiments, the rotor blades <NUM> may contain one or more passages for cooling; e.g., passage(s) <NUM> as shown, for example, in <FIG>.

Claim 1:
A rotor assembly for a gas turbine engine, comprising:
a first rotor disk (180A) configured to rotate about a rotational axis (<NUM>);
a second rotor disk (180B) configured to rotate about the rotational axis (<NUM>); and
a plurality of rotor blades (<NUM>) arranged circumferentially around the rotational axis (<NUM>), each of the plurality of rotor blades (<NUM>) mounted to the first rotor disk (180A) and to the second rotor disk (180B), and the plurality of rotor blades (<NUM>) comprising a first rotor blade (<NUM>);
the first rotor blade (<NUM>) comprising an attachment (<NUM>) projecting axially along the rotational axis (<NUM>) into a first pocket (196A) in the first rotor disk (180A) and a second pocket (196B) in the second rotor disk (180B), and the attachment (<NUM>) having a dovetail cross-sectional geometry when viewed in a plane perpendicular to the rotational axis (<NUM>); and
a portion (186A) of the first rotor disk (180A) extending circumferentially across and thereby circumferentially covering the attachment (<NUM>),
characterised in that the rotor assembly further comprises:
a reinforcing ring (<NUM>) located axially between and rotatable with the first rotor disk (180A) and the second rotor disk (180B); and/or
a first reinforcing ring (<NUM>) connected to an exterior of the first rotor disk; and/or
a second reinforcing ring (<NUM>) connected to an exterior of the second rotor disk.