Rotor blade root spacer with grip element

An assembly includes a rotor disk, a rotor blade and a root spacer. The rotor disk includes a slot that extends longitudinally into the rotor disk. The rotor blade includes a blade root arranged within the slot. The root spacer is arranged with the slot between the rotor disk and the blade root. The root spacer extends longitudinally to a spacer end, and includes a grip element and a plurality of notches. The grip element is arranged at the spacer end laterally between the notches. The grip element at least partially defines the notches. The notches extend radially and longitudinally into the root spacer.

This application claims priority to PCT Patent Application No. PCT/US13/21935 filed Jan. 17, 2013, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

This disclosure relates generally to rotational equipment and, more particularly, to a root spacer for arranging between a rotor disk and a root of a rotor blade.

2. Background Information

A fan assembly for a typical turbine engine includes a plurality of fan blades arranged circumferentially around a rotor disk. Each of the fan blades includes an airfoil connected to a dovetail root. The root is inserted into a respective dovetail slot within the rotor disk, and connects the fan blade to the rotor disk. A radial height of the root is typically less than a radial height of the slot. A gap therefore extends between a radial inner surface of the root and a radial inner surface of the rotor disk within the slot. Such a gap is typically filled with a root spacer, which is sometimes also referred to as a fan blade spacer.

A typical root spacer is configured to reduce slippage and wear between the root and the rotor disk where centrifugal loading on the fan blade is relatively low; e.g., during wind milling. By filling the gap, for example, the root spacer reduces space that would otherwise be available for rotating of the root within the slot.

Various types and configurations of root spacers are known in the art. One such root spacer includes a threaded hole that extends into an end of the spacer. During engine maintenance, a tool with a threaded shaft is threaded into the hole and manipulated to pull the root spacer from the slot. The root spacer therefore has a relatively large radial thickness in order to accommodate the threaded hole. Such a relatively large radial thickness may increase the overall size and/or weight of the fan assembly as well as take away space that would otherwise be available for a larger blade root.

There is a need in the art for an improved root spacer.

SUMMARY OF THE DISCLOSURE

According to an aspect of the invention, an assembly is provided that includes a rotor disk, a rotor blade and a root spacer. The rotor disk includes a slot that extends longitudinally into the rotor disk. The rotor blade includes a blade root arranged within the slot. The root spacer is arranged with the slot between the rotor disk and the blade root. The root spacer extends longitudinally to a spacer end, and includes a grip element and a plurality of notches. The grip element is arranged at the spacer end laterally between the notches, and at least partially defines the notches. The notches extend radially and longitudinally into the root spacer, and at least one of the notches extends laterally within the root spacer.

According to another aspect of the invention, another assembly is provided that includes a rotor disk, a rotor blade and a root spacer. The rotor disk includes a slot that extends longitudinally into the rotor disk. The rotor blade includes a blade root arranged within the slot. The blade root extends longitudinally to a root end. The root spacer is arranged with the slot between the rotor disk and the blade root. The root spacer extends longitudinally to a spacer end that is approximately longitudinally aligned with the root end. The root spacer includes a grip element and a plurality of notches. The grip element is arranged at the spacer end laterally between the notches, and at least partially defines the notches. The notches extend radially and longitudinally into the root spacer.

A first of the notches may extend laterally within the root spacer. Alternatively, each of the notches may extend laterally within the root spacer.

A first of the notches may extend laterally into the root spacer. Alternatively, each of the notches may extend laterally into the root spacer.

A first of the notches may extend radially through the root spacer. Alternatively, each of the notches may extend radially through the root spacer.

A first of the notches may extend radially into the root spacer to a surface. Alternatively, each of the notches may extend radially into the root spacer to a surface.

The grip element may include a base and a flange that extends laterally from the base. The base and the flange may at least partially define a first of the notches. The flange may be a first flange, and the grip element may also include a second flange that extends laterally from the base. The base may be arranged laterally between the first and the second flanges. The base and the second flange may at least partially define a second of the notches.

The grip element may extend longitudinally to the spacer end. Alternatively, the grip element may be longitudinally recessed from the spacer end.

The slot may extend longitudinally into the rotor disk from a disk end. The spacer end may be arranged at the disk end. Alternatively, the spacer end may be approximately longitudinally aligned with the disk end.

The blade root may extend longitudinally to a root end. The spacer end may be approximately longitudinally aligned with the root end.

The slot may be one of a plurality of slots that extend longitudinally into the rotor disk. The rotor blade may be one of a plurality of rotor blades arranged circumferentially around an axis. Each of the rotor blades may include a blade root arranged within a respective one of the slots. The root spacer may be one of a plurality of root spacers. Each of the root spacers may be arranged within a respective one of the slots between the rotor disk and a respective one of the blade roots. At least some or all of the root spacers each include a grip element.

The rotor blade may be configured as or include a turbine engine fan blade. Alternatively, the rotor blade may be configured as or include any other type of turbine engine blade.

The assembly may include a gear train and a plurality of turbine engine rotors arranged along an axis. The engine rotors may include a first rotor and a second rotor. One of the engine rotors may include the rotor disk, the rotor blade and the root spacer. The gear train may connect the first rotor to the second rotor. The first rotor may be configured as or include a fan rotor, and may include the rotor disk, the rotor blade and the root spacer.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a side cutaway illustration of a geared turbine engine20that extends along an axis22between an upstream airflow inlet24and a downstream airflow exhaust26. The engine20includes a fan section28, a compressor section29, a combustor section30and a turbine section31. The compressor section29includes a low pressure compressor (LPC) section29A and a high pressure compressor (HPC) section29B. The turbine section31includes a high pressure turbine (HPT) section31A and a low pressure turbine (LPT) section31B. The engine sections28-31are arranged sequentially along the axis22within an engine housing34, which includes a first engine case36(e.g., a fan nacelle) and a second engine case38(e.g., a core nacelle).

Each of the engine sections28,29A,29B,31A and31B includes a respective rotor40-44. Each of the rotors40-44includes a plurality of rotor blades arranged circumferentially around and connected to (e.g., formed integral with or mechanically fastened, welded, brazed or otherwise adhered to) one or more respective rotor disks. The fan rotor40is connected to a gear train46; e.g., an epicyclic gear train. The gear train46and the LPC rotor41are connected to and driven by the LPT rotor44through a low speed shaft48. The HPC rotor42is connected to and driven by the HPT rotor43through a high speed shaft50. The low and high speed shafts48and50are rotatably supported by a plurality of bearings52. Each of the bearings52is connected to the second engine case38by at least one stator such as, for example, an annular support strut.

Air enters the engine20through the airflow inlet24, and is directed through the fan section28and into an annular core gas path54and an annular bypass gas path56. The air within the core gas path54may be referred to as “core air”. The air within the bypass gas path56may be referred to as “bypass air” or “cooling air”. The core air is directed through the engine sections29-31and exits the engine20through the airflow exhaust26. Within the combustion section30, fuel is injected into and mixed with the core air and ignited to provide forward engine thrust. The bypass air is directed through the bypass gas path56and out of the engine20to provide additional forward engine thrust or reverse thrust via a thrust reverser. The bypass air may also be utilized to cool various turbine engine components within one or more of the engine sections29-31.

FIG. 2is a perspective illustration of a partially assembled rotor assembly58for one of the rotors40-44; e.g., the fan rotor40. This rotor assembly58includes a rotor disk60, one or more rotor blades62(e.g., fan blades), and one or more root spacers64(e.g., fan blade spacers).

The rotor disk60extends axially along the axis22between an upstream disk end66and a downstream disk end68. The rotor disk60extends radially out to a disk outer surface70. The rotor disk60includes one or more slots72(e.g., dovetail slots) arranged circumferentially around the axis22. Referring toFIG. 3, one or more of the slots72each extends longitudinally (e.g., axially) into the rotor disk60; e.g., through the rotor disk60between the disk ends66and68. Referring now toFIG. 4, one or more of the slots72each extends radially into the rotor disk60from the outer surface70to a slot base surface74. One or more of the slots72each extends laterally (e.g., circumferentially or tangentially) between opposing slot side surfaces76and78. The base surface74extends laterally between the side surfaces76and78.

Referring toFIG. 3, one or more of the rotor blades62each includes a blade root80and an airfoil82. The blade root80extends longitudinally between an upstream root end84and a downstream root end86. Referring now toFIG. 4, the blade root80includes a root base portion88and a pair of root side portions90and92. The base portion88extends radially between the airfoil82and a root base surface94. The side portions90and92respectively extend laterally from the base portion88to opposing root side surfaces96and98. The base surface94extends laterally between the side surfaces96and98.

Referring toFIGS. 4 to 6, one or more of the root spacers64each extends longitudinally between an upstream spacer end100and a downstream spacer end102. One or more of the root spacers64each includes a spacer base portion104, one or more spacer side portions106and107, a grip element108(e.g., a T-shaped protrusion), and one or more notches110and112(e.g., L-shaped channels). The base and the side portions104,106and107extend radially between a spacer inner surface114and a spacer outer surface116. The base portion104extends laterally between the side portions106and107, and has a chord118(seeFIG. 4). The side portions106and107respectively extend laterally from the base portion104to opposing spacer sides120and122. Each of the side portions106and107has a chord124(seeFIG. 4) that may be angularly offset from the chord118by, for example, between about 135 and about 160 degrees.

Referring toFIGS. 5 and 6, the grip element108is arranged at (e.g., adjacent, proximate or on) the spacer end100laterally between the notches110and112. The grip element108includes a base126and one or more flanges128and130. The base126extends longitudinally to the spacer end100, and is arranged laterally between the flanges128and130. The flanges128and130respectively extend laterally from the base126to opposing grip sides. The base126and the first flange128at least partially define the first notch110. The first notch110, for example, extends laterally within the root spacer64between a notch first side surface132of the base portion104and the base126and the first flange128. The base126and the second flange130at least partially define the second notch112. The second notch112, for example, extends laterally within the root spacer64between a notch second side surface134of the base portion104and the base126and the second flange130. The notches110and112respectively extend longitudinally into the root spacer64to notch end surfaces136and138of the base portion104. One or more of the notches110and112extend radially through the root spacer64between the inner surface114and the outer surface116, which may enable the root spacer64to have a relatively thin radial thickness. Alternatively, referring toFIG. 7, one or more of the notches110and112may respectively extend radially into the root spacer64′ to notch inner surfaces140and142(or notch outer surfaces).

Referring toFIG. 2, the rotor blades62are arranged circumferentially around the axis22. The blade roots80and the root spacers64are respectively arranged within the slots72. Referring toFIG. 3, the spacer end100and the root end84may be substantially longitudinally aligned and/or respective arranged at the disk end66. Alternatively, the spacer end100and/or the root end84may be substantially longitudinally aligned with the disk end66. The spacer end102and the root end86may also or alternatively be substantially longitudinally aligned and/or respective arranged at the disk end68. Alternatively, the spacer end102and/or the root end86may be substantially longitudinally aligned with the disk end68. Referring toFIG. 4, the root side portions90and92extend laterally between the root base portion88and the rotor disk60. The root side surfaces96and98may respectively engage (e.g., contact) the slot side surfaces76and78. The root spacer64is arranged radially between the blade root80and the rotor disk60. The spacer outer surface116may engage one or more of the surfaces94,96and98, and/or the spacer inner surface114may engage the slot base surface74.

Referring toFIGS. 4, 6 and 8, a tool144with clamping grip members146and148may be mated with the grip element108during engine maintenance to remove the root spacer64from a respective slot72. The grip members146and148, for example, may be respectively inserted into the notches110and112and clamped against the grip base126. The tool144may subsequently be manipulated to longitudinally pull the root spacer64out of the slot72. One or more of the grip members146and148may be coated with a soft material such as rubber to provide a buffer between the grip members146and148and the blade root80and/or the rotor disk60. One or more of the grip members146and148may also or alternatively be coated with various other materials, or may be uncoated.

FIG. 9illustrates an end150of another root spacer152for the rotor assembly58ofFIG. 2. In contrast to the root spacer64ofFIG. 5, a grip element156of the root spacer152is longitudinally recessed from the spacer end150.

FIG. 10illustrates an end158of another root spacer160for the rotor assembly58ofFIG. 2. In contrast to the root spacer64ofFIG. 5, one or more of the notches110″ and112″ of the root spacer160extends laterally into the root spacer160. The first notch110″, for example, extends laterally through the side portion106″ and into the base portion104″ to the grip element108. The second notch112″ extends laterally through the side portion107″ and into the base portion104″ to the grip element108. The notch end surfaces136″ and138″ therefore respectively form end surfaces of the side portions106″ and107″.

FIG. 11illustrates an end162of another root spacer164for the rotor assembly58ofFIG. 2. In contrast to the root spacer64ofFIG. 5, a grip element166of the root spacer164is configured without the flanges128and130shown inFIGS. 5 and 6. The notches110″′ and112″′ therefore are respectively laterally defined between the side surfaces132and134and the base126″′.

In some embodiments, one or more of the root spacers may be constructed from a polymeric material such as plastic. In other embodiments, one or more of the root spacers may be constructed from metal. The present invention, however, is not limited to any particular root spacer materials.

The slots, the blade roots, the root spacers, the grip elements and the notches may have various configurations other than those described above and illustrated in the drawings. For example, the root spacer may include one or more channels, slots, dimples, through-holes, etc. that may reduce the weight of the root spacer and/or conform to an alternate embodiment root and/or slot configuration. The grip member may be configured as an L-shaped protrusion, or any other type of protrusion. The notches may be defined by one or more arcuate surfaces. The present invention therefore is not limited to any particular rotor disk, rotor blade or root spacer types or configurations.

The terms “upstream”, “downstream”, “inner” and “outer” are used to orientate the components of the rotor assembly described above relative to the turbine engine and its axis. A person of skill in the art will recognize, however, one or more of these components may be utilized in other orientations than those described above. For example, the grip element may be arranged at the downstream end of the rotor disk. The present invention therefore is not limited to any particular rotor assembly spatial orientations.

A person of skill in the art will recognize the rotor assembly 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, 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 and/or a compressor section. Alternatively, the rotor assembly may be included in a turbine engine configured without a gear train. The rotor assembly may be included in a turbine engine configured with a single spool, with two spools as illustrated inFIG. 1, or with more than two spools. The present invention therefore is not limited to any particular types or configurations of turbine engines or rotational equipment.