The invention relates to sealing bands used in gas turbines, and more particularly, to a sealing band arrangement that includes a locking pin having a locking pin mating surface that abuts against a mating surface of a seal strip segment to thereby lock the locking pin and the seal strip segment together wherein a portion of the locking pin is located within a disk rotor aperture to stop circumferential movement of the seal strip segment relative to rotor disks.
In various multistage turbomachines used for energy conversion, such as gas turbines, a fluid is used to produce rotational motion. Referring to
The rotor blades are mounted to disks that are supported for rotation on a rotor shaft. Annular arms extend from opposed surfaces of adjoining disks to form pairs of annular arms each separated by a gap. A cooling air cavity is formed on an inner side of the annular arm pairs between the disks of mutually adjacent stages. In addition, a labyrinth seal may be provided on an inner circumferential surface of stationary vane structures that cooperate with the annular arms to form a gas seal between a path for the hot combustion gases and the cooling air cavity. Each annular arm includes a slot for receiving a seal strip, known as a “belly band”, which spans the gap between each annular arm pair to stop a flow of cooling air from the cooling air cavity into a path for the combustion gas 24. The seal strip may include multiple segments that extend in a circumferential direction and are interconnected at lapped or stepped ends.
During use, the seal strips may shift in a circumferential direction relative to each other. Shifting may cause one end of a segment to increase an overlap with an adjacent segment, while an opposite end of the segment will move out of engagement with an adjacent segment thus opening a gap for passage of gases through the seal strip. Therefore, an anti-rotation mechanism is provided for stopping circumferential shifting of seal strip segments.
An anti-rotation mechanism that is originally installed at the factory during assembly of a gas turbine exhibits wear after a prolonged period of turbine operation. In order to replace the anti-rotation mechanism with one of the same design, the rotor has to be de-stacked or disassembled which leads to undesirable downtime and increased cost for gas turbines that are currently in the field. Replacement anti-rotation mechanisms that do not require de-stacking of the rotor utilize welding operations to join mechanism components, require modification of a disk and/or are difficult to install. However, performing a welding operation or making modifications in the field is difficult and accidental welding of the disk during repair may occur.
A sealing band arrangement is disclosed for a gas turbine including first and second adjoining rotor disks separated by a gap wherein the first rotor disk includes an aperture. The sealing band arrangement includes at least one seal strip segment located within the gap, wherein the seal strip segment includes a raised portion having a first mating surface. The sealing arrangement further includes a locking pin having a planar section for receiving the first raised surface. The locking pin also includes a pin section having a second mating surface that abuts against the first mating surface to thereby lock the locking pin and the seal strip segment together. Further, the pin section is located within the aperture to stop circumferential movement of the seal strip segment relative to the first and second disks. The sealing band arrangement serves to seal a first air cavity from a second air cavity in the gas turbine.
Those skilled in the art may apply the respective features of the present invention jointly or severally in any combination or sub-combination.
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
Although various embodiments that incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings. The invention is not limited in its application to the exemplary embodiment details of construction and the arrangement of components set forth in the description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
Referring to
Disk cavities 48, 50 are located radially inward from the gas passage 46. Purge air is provided from cooling gas passing through internal passages in the vane assemblies 38 to the disk cavities 48, 50 to cool blades 40 and to provide a pressure to balance against the pressure of the hot gases in the gas passage 46. In addition, interstage seals including labyrinth seals 52 are supported at a radially inner side of the vane assemblies 38 and are engaged with surfaces defined on paired annular disk arms 54, 56 that extend axially from opposed surfaces of adjoining disks 42.
An annular cooling air cavity 58 is formed between the opposed surfaces of adjoining disks 42 on a radially inner side of the paired annular disk arms 54, 56. The annular cooling air cavity 58 receives cooling air passing through disk passages to cool the disks 42. A sealing band 60 or “belly band” seal is positioned between the annular cooling air cavity 58 and the disk cavities 48, 50. The sealing band 60 prevents or substantially limits the flow of gases between the cooling air cavity 58 and the disk cavities 48, 50.
Referring to
Referring to
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Alternatively, the aperture 114 may be pre-existing, i.e. previously provided for engagement with an anti-rotation mechanism originally installed at the factory during assembly of a gas turbine. Thus, the present invention does not require machining or other modification to the arms 54 or 56. Therefore, the present invention enables field replacement of an existing anti-rotation mechanism and belly band seal.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
Number | Name | Date | Kind |
---|---|---|---|
3966356 | Irwin | Jun 1976 | A |
4311432 | Kildea | Jan 1982 | A |
4650394 | Weidner | Mar 1987 | A |
5141395 | Carroll et al. | Aug 1992 | A |
5387082 | Matyscak | Feb 1995 | A |
5865600 | Mori et al. | Feb 1999 | A |
6315301 | Umemura et al. | Nov 2001 | B1 |
7549845 | Uwami et al. | Jun 2009 | B2 |
20040120806 | Darkins et al. | Jun 2004 | A1 |
20050249588 | Ferra et al. | Nov 2005 | A1 |
20090081033 | Schiavo et al. | Mar 2009 | A1 |
20090148279 | Shaefer et al. | Jun 2009 | A1 |
20090191050 | Nereim et al. | Jul 2009 | A1 |
20100074731 | Wiebe et al. | Mar 2010 | A1 |
20120082540 | Dziech et al. | Apr 2012 | A1 |
20130106066 | Sarawate et al. | May 2013 | A1 |
20140119899 | Nereim et al. | May 2014 | A1 |
20140119900 | Gurao et al. | May 2014 | A1 |
Number | Date | Country | |
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20160010478 A1 | Jan 2016 | US |