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.
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.
The foregoing features and the operation of the invention will become more apparent in light of the following description and the accompanying drawings.
Each of the engine sections 28, 29A, 29B, 31A and 31B includes a respective rotor 40-44. Each of the rotors 40-44 includes 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 rotor 40 is connected to a gear train 46; e.g., an epicyclic gear train. The gear train 46 and the LPC rotor 41 are connected to and driven by the LPT rotor 44 through a low speed shaft 48. The HPC rotor 42 is connected to and driven by the HPT rotor 43 through a high speed shaft 50. The low and high speed shafts 48 and 50 are rotatably supported by a plurality of bearings 52. Each of the bearings 52 is connected to the second engine case 38 by at least one stator such as, for example, an annular support strut.
Air enters the engine 20 through the airflow inlet 24, and is directed through the fan section 28 and into an annular core gas path 54 and an annular bypass gas path 56. The air within the core gas path 54 may be referred to as “core air”. The air within the bypass gas path 56 may be referred to as “bypass air” or “cooling air”. The core air is directed through the engine sections 29-31 and exits the engine 20 through the airflow exhaust 26. Within the combustion section 30, 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 path 56 and out of the engine 20 to 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 sections 29-31.
The rotor disk 60 extends axially along the axis 22 between an upstream disk end 66 and a downstream disk end 68. The rotor disk 60 extends radially out to a disk outer surface 70. The rotor disk 60 includes one or more slots 72 (e.g., dovetail slots) arranged circumferentially around the axis 22. Referring to
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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 in
While various embodiments of the present invention have been disclosed, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. For example, the present invention as described herein includes several aspects and embodiments that include particular features. Although these features may be described individually, it is within the scope of the present invention that some or all of these features may be combined within any one of the aspects and remain within the scope of the invention. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.
Filing Document | Filing Date | Country | Kind |
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PCT/US13/21935 | 1/17/2013 | WO | 00 |