The present invention relates generally to a seal and more specifically towards a flexible seal for preventing the leakage of hot gases in a gas turbine engine.
Gas turbine engines typically comprise a compressor, at least one combustor, and a turbine. The pressure of air passing through the compressor is raised through each stage of the compressor and is then directed towards the combustion system. Gas turbine combustion systems mix fuel with the compressed air and ignite this mixture to create hot combustion gases. The hot combustion gases are then directed towards a turbine, which produces work, typically for thrust, or shaft power if the engine shaft is connected to an electrical generator.
The turbine engine is comprised of numerous individual components that are fixed together in order to provide the path through which air and combustion gases pass while undergoing the process of generating the thrust or shaft power previously mentioned. It is imperative that all gaps between these individual components be controlled in order to minimize losses in compressor, combustion, or turbine efficiency due to undesirable leakages. Due to various thermal and mechanical loads on these individual components, often times the sealing region between mating components moves or twists. Therefore, it is imperative that any seal between mating components be compliant to such movement. While various fastening and sealing means are employed to control these leakages, one common means, especially in the turbine section, is the use of individual metallic seals.
Most common metallic seal designs have included individual strips of metal and a metallic cloth seal. Examples of these types of prior art seals are shown in
An alternate prior art gas turbine engine seal is shown in
Therefore, in light of the requirements to provide a compliant seal to operate under high temperatures and mechanical loads, an improved seal is desired that overcomes the shortfalls of the prior art.
The present invention discloses a seal that extends between adjacent slots of a gas turbine engine. The seal comprises an outer sleeve having a first generally planar member including a length, a first end, a second end, a width extending therebetween, and a first thickness. A second generally planar member is positioned on the opposite side of the first generally planar member and has a raised portion. Extending from proximate the first end to proximate the second end and located in between the first and second generally planar members is a plurality of third generally planar members. The plurality of third generally planar members of the seal are arranged such that they are fixed to both the first and second generally planar members. The various planar members, which are preferably fabricated from relatively thin sections of sheet metal, are secured together by a means such as welding, where the welds are located generally along a centerline. The use of multiple planar members secured together along the seal centerline provides a device capable of sealing slots between adjacent engine components, that has the required flexibility to conform to mechanical and thermal loads, while having significantly lower stresses along the weld joint region.
In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
The preferred embodiment of the present invention is shown in detail in
Located in between first generally planar member 52 and second generally planar member 58 is a plurality of third generally planar members 62 that each have a third thickness 63 and extend from proximate first end 54 to proximate second end 55. Depending on the dimensions of the slot in which the seal is to be placed as well as the desired amount of seal movement, the number of third generally planar members can vary. However, in the preferred embodiment, three members are utilized in between first and second generally planar members as well as a shorter member that is located within the raised portion 61 of second generally planar member 58. The more pliability desired will utilize fewer third generally planar members while a stiffer seal design will require more third generally planar members, for a given member thickness. In order to overcome the shortcomings of the prior art seal, in which multiple slabs can move relative to one another, the present invention fixes third generally planar members 62 to first and second generally planar members 52 and 58, respectively. These planar members can be affixed by a variety of means, but the preferred means is through a plurality of spot welds 64, as shown in
The preferred embodiment of the present invention further incorporates substantially rounded first and second ends, 54 and 55, as shown in
A further benefit of the rounded ends of outer sleeve 51 is with respect to the position of welds 64. Seal 50 further comprises a centerline A-A, as shown in
Depending on the operating requirements, the seal material and respective member thickness can vary. However, it is preferred that seal 50 is fabricated from a high temperature alloy such as Haynes 188. Furthermore, due to outer sleeve 51 serving as the outermost layer and generally the region of contact with an engine seal slot, it is preferred that first thickness 57 is greater than both second thickness 59 and third thickness 63. Accordingly, outer sleeve 51 is fabricated from a sheet having a first thickness between 0.015 inches and 0.050 inches while second and third generally planar members 58 and 62 are fabricated from a sheet having a second and third thickness, respectively, of between 0.010 inches and 0.040 inches.
The configuration presented in the preferred embodiment of the present invention provides for a gas turbine seal fabricated from a plurality of generally planar members, preferably spot welded together along a neutral axis. As a result, the seal, which provides a seal to reduce or eliminate undesirable leakage resulting in engine performance loss, has improved shear and bending capability while reducing the stress loads applied to the weld joints.
While the invention has been described in what is known as presently the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment but, on the contrary, is intended to cover various modifications and equivalent arrangements within the scope of the following claims.
This application hereby claims the benefit of U.S. Provisional Patent Application Ser. No. 60/623,515, which was filed Oct. 29, 2004, entitled FLEXIBLE SEAL FOR A GAS TURBINE.
Number | Name | Date | Kind |
---|---|---|---|
2130110 | Victor et al. | Sep 1938 | A |
3975114 | Kalkbrenner | Aug 1976 | A |
4468044 | Ulmer et al. | Aug 1984 | A |
4645217 | Honeycutt et al. | Feb 1987 | A |
5449181 | Miyaoh | Sep 1995 | A |
5934687 | Bagepalli et al. | Aug 1999 | A |
5961126 | Miyaoh | Oct 1999 | A |
5997247 | Arraitz et al. | Dec 1999 | A |
6199871 | Lampes | Mar 2001 | B1 |
6431825 | McLean | Aug 2002 | B1 |
6521373 | Suzuki et al. | Feb 2003 | B1 |
6994353 | Kinoshita | Feb 2006 | B2 |
20030039542 | Cromer | Feb 2003 | A1 |
Number | Date | Country | |
---|---|---|---|
20060091617 A1 | May 2006 | US |
Number | Date | Country | |
---|---|---|---|
60623515 | Oct 2004 | US |