US20080044284A1

US20080044284A1 - Segmented fluid seal assembly

Info

Publication number: US20080044284A1
Application number: US11/505,165
Authority: US
Inventors: Ioannis Alvanos
Original assignee: United Technologies Corp
Current assignee: RTX Corp
Priority date: 2006-08-16
Filing date: 2006-08-16
Publication date: 2008-02-21

Abstract

A rotor assembly for a turbine engine includes a rotor disk having rotor blades mounted about the circumference and rotatable about a central longitudinal axis. A fluid seal extends about the circumference of the rotor disk in close proximity to a stationary component to separate the space between the rotor blades and a stationary component into separate cavities. The fluid seal includes a plurality of disk seal segments and a plurality of blade seal segments. The disk seal segments each attach to the rotor disk between the rotor blades. The blade seal segments attach to the blades. After the blades are assembled the blade seal segments and the disk seal segments align to form a segmented, ring-like fluid seal around the circumference of the rotor disk.

Description

This application discloses subject matter related to co-pending US patent applications “HAMMERHEAD FLUID SEAL” (U.S. patent application Ser. No. 11/146,801); “COMBINED BLADE ATTACHMENT AND DISK LUG FLUID SEAL” (U.S. patent application Ser. No. 11/146,798); and “BLADE NECK FLUID SEAL” (U.S. patent application Ser. No. 11/146,660), each filed on Jul. 7, 2005, and “INTEGRATED BLADED FLUID SEAL” (U.S. patent application Ser. No. 11/260,357), filed on Oct. 27, 2005. The disclosures of each aforementioned application are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention generally relates to an arrangement for loading and retaining a segmented fluid seal assembly within a gas turbine engine.
Turbine engines include high and low rotor spools comprising multiple rotor disks. Fluid seals are formed integrally into each rotor disk to contact stator components, such as a stator vane, support or tangential on-board injector. The seals restrict leakage of compressed air from between the stator component and the rotor disks and separate the lower pressure gaspath air from the higher pressure compressed air used for cooling.
Due to the rotor disk geometry, multiple machining passes are required to produce the thin sectional area required for the fluid seal. This is unduly complex. Also, during operation of the engine the fluid seal may contact an abradable material on the stationary components, causing wear. Because the fluid seal is integrally formed with the rotor disk of the compressor, the entire rotor disk must be repaired or replaced when the fluid seal has worn. The replacement costs for the seal components can be reduced by making the fluid seals non-integral to the rotor disk, and segmented.
An improved arrangement for loading and retaining fluid seals within a gas turbine engine is needed.

SUMMARY OF THE INVENTION

An example rotor for a turbine engine according to this invention includes an arrangement for incorporating a fluid seal assembly, which is separate from the rotor disk.
A typical turbine engine rotor includes multiple rotor disks with rotor blades mounted about the circumference of each of the rotor disks. A plurality of stator vanes extend axially between adjacent rotor disks. A fluid seal assembly extends about the circumference of each rotor disk in close proximity to a stationary component of the rotor. The fluid seal assembly separates the space between the rotor blades and stationary components into separate, pressurized cavities.
The fluid seal assembly includes a plurality of disk seal segments and a plurality of blade seal segments spaced around the circumference of the rotor disk and fitting together to form a segmented fluid seal. Stress placed on the rotor disk during engine operation does not transfer to the fluid seal because the disk seal segments and blade seal segments are separate elements from the rotor disk and segmented from one another.
The disk seal segments each have a disk attaching feature and the rotor disk includes a complimentary shaped seal attaching feature. The disk attaching feature interfits with the seal attaching feature to retain the disk seal segment to the rotor disk.
The blade seal segments each have a blade attaching feature and each of the rotor blades include a complimentary shaped seal attaching feature. The blade attaching feature interfits with the seal attaching feature to retain the blade seal segment to the rotor blade. Once the blade seal segment is attached, the rotor blade is loaded into a blade slot in the rotor disk. After the rotor blade is assembled in the blade slot the blade seal segments and the disk seal segments fit together to form a segmented fluid seal around the circumference of the rotor disk.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an example turbine engine of the present invention;

FIG. 2 illustrates a portion of a cross-section of a typical rotor for the example turbine engine of the present invention;

FIG. 3 is an enlarged view of region 3-3 from FIG. 2, illustrating a portion of an example fluid seal;

FIG. 4 is a perspective view of an example disk seal segment and rotor disk of the present invention during assembly;

FIG. 5 is a perspective view of an example blade seal segment and rotor blade of the present invention during assembly;

FIG. 6 illustrates the rotor disk after the rotor blades, blade seal segments and disk seal segments are assembled;

FIG. 7 illustrates a disk seal segment having a first interlocking feature and a blade seal segment having a second interlocking feature; and

FIG. 8 is a perspective view of another example blade seal segment and rotor blade of the present invention during assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a schematic view of a turbine engine 10. Air is pulled into the turbine engine 10 by a fan 12 and flows through a low pressure compressor 14 and a high pressure compressor 16. Fuel is mixed with the air and combustion occurs within the combustor 18. Exhaust from combustion flows through a high pressure turbine 20 and a low pressure turbine 22 prior to leaving the engine through an exhaust nozzle 24.
FIG. 2 illustrates a portion of a cross-section of a typical turbine engine rotor showing a rotor disk 26, which is one of several defining a turbine rotor. Each rotor disk 26 of the rotor rotates about an axis A located along the longitudinal centerline of the turbine engine 10. A plurality of rotor blades 28 are mounted about the circumference of each rotor disk 26. A plurality of stationary stator vanes 30 extend radially inwardly between the rotor blades 28 of axially adjacent rotor disks 26, as known.
Each rotor disk 26 includes a disk rim 32. The disk rim 32 is located at the radially outer portion of the disk and secures the rotor blades 28. A fluid seal 34 extends about the circumference of the disk rim 32. The fluid seal 34 is preferably formed of the same material as the rotor disk 26 such as any ferrous, nickel, or ceramic materials. The fluid seal 34 is in close proximity to a stationary component 36 of the compressor such as a stator, a support or a tangential on-board injector (TOBI). The fluid seal 34 is illustrated as extending axially toward the stationary component 36.
A cavity 38 is located axially above the fluid seal 34 and defined by the stator vane 30 and the rotor blade 28. Lower pressure air within the cavity 38 is flowing circumferentially about the axis A of rotation for the rotor disk 26. An interior cavity 40 is located axially below the fluid seal 34 and defined by the rotor disk 26 and the stationary component 36. A TOBI nozzle 42 leading from the stationary component 36 allows higher pressure cooling air to reach the interior cavity 40.
FIG. 3 is an enlarged view of the example fluid seal 34. The fluid seal 34 includes a main body 44 and a plurality of knife edges 46 extending from the main body 44 toward the stationary component 36. The stationary component 36 can include an abradable honeycomb material 48 at a location corresponding to of the knife edges 46. During operation of the compressor the knife edges 46 are contacting the abradable honeycomb material 48. The knife edges 46 rotate with the rotor disk 26 while the abradable honeycomb material is stationary. During extreme radial excursions of the rotor, the knife edges 46 and the abradable honeycomb material 48 may interfere, causing wear. When the wear becomes sufficient the fluid seal 34 and/or the abradable honeycomb material 48 must be repaired or replaced.
Referring to FIGS. 4 and 5 the fluid seal 34 includes a plurality of disk seal segments 50 and a plurality of blade seal segments 52 spaced around the circumference of the disk rim 32 and fitting together to form a segmented fluid seal 34 about the disk rim 32. The disk seal segments 50, shown in FIG. 4, are mounted to the disk rim 32 between the rotor blades 28. The blade seal segments 52 are attached to the rotor blades 28 and then assembled into the rotor disk 26.
Once assembled, each of the disk seal segments 50 and blade seal segments 52 mates with a circumferentially adjacent seal segment 50 or 52 to provide a segmented, ring-like structure. Stress placed on rotor disk 26 during engine operation does not transfer to the fluid seal 34 because the disk seal segments 50 and blade seal segments 52 are separate elements from the rotor disk 26 and segmented from one another. The arrangement also allows for replacement of individual segments 50 and 52 without requiring an entire new rotor disk 26.
The disk seal segments 50 each have a disk attaching feature 54 and the disk rim 32 includes a corresponding seal attaching feature 56. The disk attaching feature 54 interfits with the seal attaching feature 56 to retain the disk seal segment 50 to the disk rim 32. In the example shown, the disk attaching feature 54 is a groove and the seal attaching feature 56 is a tongue. The disk seal segments 50 are assembled onto the rotor disk 26 prior to assembly of the rotor blades 28. Alternatively, the disk seal segments 50 may be integrally formed with the rotor disk 26.
The blade seal segments 52 each have a blade attaching feature 58 and each of the blades 28 include a seal attaching feature 60. The blade attaching feature 58 interfits with the seal attaching feature 60 to retain the blade seal segment 52 to the rotor blade 28. In the example shown, the blade attaching feature 58 is a groove and the seal attaching feature 60 is a tongue formed in the base of the rotor blade 28. Once the blade seal segment 52 is attached, the rotor blade 28 is loaded into a blade slot 62 in the disk rim 32. Walls 64 in the disk rim 32 define the individual blade slots 62. Then the rotor blade 28 is loaded in the blade slot 62 the walls 64 prevent the blade seal segment 52 from separating from the rotor blade 28.
FIG. 6, illustrates the rotor disk 26 after the rotor blades 28 are assembled in the blade slots 62. The blade seal segments 52 and the disk seal segments 50 align to form a segmented, ring-like fluid seal 34 around the circumference of the rotor disk 26. In addition, the blade seal segments 52 prevent the disk seal segments 50 from separating from the seal attaching feature 56 (shown in FIG. 4).
FIG. 7 shows the disk seal segment 50 having a first overlapping feature 74 and the blade seal segment 52 having a second overlapping feature 76. The first overlapping feature 74 and the second overlapping feature 76 interfit with one another to align the disk seal segments 50 with the blade seal segments 52, thus reducing circumferential leakage between the segments 50 and 52. The first overlapping feature and the second overlapping feature can be a ship lap, tongue and groove or other interfitting elements know in the art.
FIG. 8 illustrates another example embodiment including a plurality of blade seal segments 66. The blade seal segments 66 each have a blade attaching feature 68 and each of the blades 28 include a seal attaching feature 70. The blade attaching feature 68 interfits with the seal attaching feature 70 to retain the blade seal segment 66 to the rotor blade 28. Once the blade seal segment 66 is attached, the rotor blade 28 is loaded into a blade slot 62 in the disk rim 32. Walls 64 in the disk rim 32 define the individual blade slots 62. When the rotor blade 28 is loaded in the blade slot 62, the walls 64 prevent the blade seal segment 66 from separating from the rotor blade 28.
Each of the blade seal segments 66 have a main body 72 which extends outward to contact a main body 72 of the circumferentially adjacent blade seal segment 66. After the rotor blade 28 is assembled in the blade slot 62 the blade seal segments 66 fit together to form a segmented, ring-like fluid seal 34 around the circumference of the rotor disk 26. In this embodiment, disk seal segments 50 are not necessary because there is no gap between one blade seal segment 66 and the next blade seal segment 66.
Although the example embodiment discloses an arrangement of assembling fluid seal segments onto a rotor disk for a turbine rotor the arrangement may be used for any rotor and seal assembly.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

Claims

1. A bladed rotor assembly comprising:

a rotor disk defining a disk rim and having a plurality of rotor blades mounted to the disk rim; and

a plurality of blade seal segments with one mounted to each of the plurality of rotor blades wherein the plurality of blade seal segments form a seal located about a circumference of the disk rim.

2. The bladed rotor assembly of claim 1, wherein the seal further comprises a plurality of disk seal segments with one located between adjacent pairs of the blade seal segments.

3. The bladed rotor assembly of claim 2, wherein the disk seal segments comprise a disk mounting feature and the disk rim comprises a complimentary shaped seal mounting feature to interfit with the disk mounting feature.

4. The bladed rotor assembly of claim 1, wherein the blade seal segments each comprise a knife edge extending toward a stationary component.

5. The bladed rotor assembly of claim 4, wherein the knife edges extend about the circumference of the disk rim to contact the knife edge of the adjacent blade seal segment forming a segmented, ring-like knife edge.

6. The bladed rotor assembly of claim 4, wherein the stationary component is a tangential on-board injector, a support or a stator vane.

7. The bladed rotor assembly of claim 1, wherein each of the plurality of blade seal segments comprise an attaching feature corresponding to a seal attaching portion of a rotor blade.

8. The bladed rotor assembly of claim 7, wherein the disk rim comprises a plurality of blade slots each for receiving the rotor blade and the blade seal segment.

9. A bladed rotor assembly comprising:

a plurality of blade seal segments with one mounted between each of the plurality of rotor blades and the disk rim; and

a plurality of disk seal segments mounted to the disk rim between adjacent pairs of the plurality of blade seal segments, wherein the plurality of blade seal segments and the plurality of disk seal segments align to form a seal located about the circumference of the disk rim.

10. The bladed rotor assembly of claim 9, wherein the seal formed by the plurality of blade seal segments and the plurality of disk seal segments extends toward a stator component.

11. The bladed rotor assembly of claim 10, wherein the stator component is a tangential on-board injector, a support or a stator vane.

12. The bladed rotor assembly of claim 9 wherein each of the plurality of blade seal segments comprise an attaching feature corresponding to a seal attaching portion of the rotor blades.

13. The bladed rotor assembly of claim 9, the disk rim comprises a plurality of blade slots each for receiving the rotor blade and the blade seal segment.

14. The bladed rotor assembly of claim 9, wherein the disk rim comprises a disk attaching feature corresponding to an attaching feature on the disk deal segment.

15. A fluid seal assembly comprising:

a plurality of blade seal segments each having a body defining a knife edge protruding from the body and towards a turbine engine component; and

a plurality of disk seal segments each having a body defining a knife edge protruding from the body and towards the turbine engine component, wherein the plurality of blade seal segments interfit with the plurality of disk seal segments to form a segmented, ring-like fluid seal.

16. The fluid seal assembly of claim 15, comprising a blade attaching feature on each of the plurality of blade seal segments for attaching each blade seal segment to a rotor blade and a disk attaching feature on each of the plurality of disk seal segments for attaching each disk seal segment to a rotor disk

17. The fluid seal assembly of claim 15, comprising a first interlocking feature on each of the plurality of blade seal segments and a second interlocking feature on each of the plurality of disk seal segments, wherein the first interlocking feature and the second interlocking feature on adjacent blade seal segments and disk seal segments are complimentary shaped and interfit with one another.