This application relates generally to a turbine blade including a mistake proof tab that prevents intermixing of different blade designs in a turbine disk of a turbine engine.
Gas turbine engines generally include a turbine disk and a plurality of removable turbine blades. The turbine blades should all have a similar blade design. Intermixing of blade designs can affect operation and/or reliability of the gas turbine engine.
As shown in
There is a need in the art for a turbine blade that includes a mistake proof feature that prevents intermixing of turbine blade designs in a turbine disk of a turbine engine.
A turbine blade includes a platform, an airfoil located on one side of the platform, and a base located on an opposite side of the platform. The base includes an attachment portion that is receivable in a blade retention slot of a turbine disk and a shelf located outside the turbine disk. The shelf includes a mistake proof feature that projects from an outer surface of the shelf.
In another example, a turbine assembly includes a turbine disk including a plurality of blade retention slots and a plurality of turbine blades. One turbine blade is received in each of the blade retention slots. Each of the plurality of turbine blades includes a platform, an airfoil located on one side of the platform, and a base located on an opposite side of the platform. The base includes an attachment portion that is receivable in one of the blade retention slots of the turbine disk and a shelf located outside the turbine disk. The shelf includes a mistake proof feature that projects from an outer surface of the shelf. A space is defined between the mistake proof feature of each of the turbine blades and an outer surface of the shelf of an adjacent turbine blade.
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.
As shown in
A central longitudinal axis B passes through a center of a width E of a bottom surface 72 of the base 36 of the turbine blade 24. A distance C1 is defined between the central longitudinal axis B and an outer surface 64 of the shelf 38 on the suction side 30 of the turbine blade 24, and a distance C2 is defined between the central longitudinal axis B and an outer surface 66 of the shelf 38 on the pressure side 28 of the turbine blade 24. The distance C1 is less than the distance C2 and less than the distance X1 of the prior art turbine blade 200. The distance C1 and the distance C2 together define a width of the turbine blade 24. In one example, the shelf 38 on the suction side 30 includes a cutback or trimmed back portion to prevent interference with an adjacent turbine blade, as described below. The shape and distance C2 of the shelf 38 on the suction side 30 of the turbine blade 24 can be formed or defined by casting, machining or casting with further machining.
The shelf 38 also has a depth D defined between a front and a back of the base 36, and the fingers 42 and the grooves 44 extend along the depth D. The depth D is substantially perpendicular to the central longitudinal axis B.
As shown in
The blade retention slots 54 have a profile that is complementary to the profile of the base 36 of the turbine blade 24. When the turbine blade 24 is to be installed in the turbine disk 46, the attachment portion 40 of the base 36 of the turbine blade 24 is aligned with one of the blade retention slots 54. The fingers 42 of the turbine blade 24 align with grooves 60 of the blade retention slot 54, and the grooves 44 of the turbine blade 24 align with fingers 58 of the blade retention slot 54. The turbine blade 24 is then slid relative to the turbine disk 46 to receive the turbine blade 24 in the blade retention slot 54. The shelf 38 is located outside the outer perimeter surface 52 of the turbine disk 46. Each blade retention slot 54 receives the base 36 of one of the turbine blades 24.
Returning to
The tab 62 extends substantially perpendicular to the outer surface 66 of the shelf 38. The tab 62 also has a width Q defined between the outer surface 66 of the shelf 38 and an outer surface 70 of the tab 62, the outer surfaces 66 and 70 being substantially parallel. Although the tab 62 is disclosed as being located on the pressure side 28 of the turbine blade 24, it is to be understood that the tab 62 could also be located on the suction side 30 of the turbine blade 24.
The tab 62 can be formed during casting of the turbine blade 24 to provide a visual and measurable feature on the turbine blade 24 during manufacture and assembly of the turbine blade 24. Once cast, the tab 62 can be machined to further define the shape of the tab 62. The tab 62 prevents the turbine blade 24 from being mistakenly assembled with, or confused for, the prior art turbine blade 200 during machining and assembly. Mixing the turbine blade 24 and the prior art turbine blade 200 can cause vibrations in the turbine engine 10. The tab 62 provides a low stress and balance-neutral approach to preventing misassembled turbine blades 24.
As shown in
When two turbine blades 24a and 24b are located in adjacent blade retention slots 54a and 54b, respectively, of the turbine disk 46, the tab 62 of the turbine blade 24a of the turbine blade 24a faces the outer surface 64 of the shelf 38 of the turbine blade 24b. As the shelf 38 located on the suction side 30 of the turbine blade 24b has a reduced distance C1 (due to the cut back or trimmed back portion), as compared to the distance X1 of the prior art turbine blades 200a and 200b, the tab 62 does not hinder installation of the turbine blades 24a and 24b as a space 68 is defined between the outer surface 70 of the tab 62 and the outer surface 64 of the shelf 38, maintaining proper clearances between the turbine blades 24. The tab 62 of the turbine blades 24a and 24b prevents inadvertent installation of both the prior art turbine blades 200a and 200b and the turbine blades 24a and 24b in the same turbine disk 46.
As shown in
In one example, the turbine blades 24a and 24b are installed in the blade retention slots 54a and 54b, respectively, of the turbine disk 46. If the prior art turbine blade 200a is attempted to be installed in the blade retention slot 54c, the tab 62 prevents insertion of the turbine blade 200a into the adjacent blade retention slot 54c. The shelf 208 of the turbine blade 200a (which has a distance X1 between the outer surface 210 of the shelf 208 and the central longitudinal axis Y that is greater than the distance C1 between the outer surface 64 of the shelf 38 of the turbine blade 24 and the longitudinal central axis B) contacts the tab 62, preventing insertion of the prior art turbine blade 200 in the blade retention slot 54c of the turbine disk 46. In this example, only turbine blades 24a and 24b can be installed in the turbine disk 46, maintaining proper clearances between the turbine blades 24a and 24b.
In another example, the prior art turbine blades 200a and 200b are installed into the blade retention slots 54c and 54d, respectively, of the turbine disk 46. If a turbine blade 24b is attempted to be installed in the blade retention slot 54b, the shelf 208 (which has a distance X1 between the outer surface 210 of the shelf 208 and the central longitudinal axis Y that is greater than the distance C1 between the outer surface 64 of the shelf 38 of the turbine blade 24 and the longitudinal central axis B of the turbine blade 24b) prevents insertion of the turbine blade 24b into the adjacent blade retention slot 54b. That is, the tab 62 of the turbine blade 24b contacts the shelf 208 of the prior art turbine blade 200a, preventing insertion of the turbine blade 24b into the blade retention slot 54b. In this example, only turbine blades 200a and 200b can be installed in the turbine disk 46, maintaining proper clearances between the turbine blades 200a and 200b.
Although
The foregoing description is only exemplary of the principles of the invention. Many modifications and variations are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than using the example embodiments which have been specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.
Number | Name | Date | Kind |
---|---|---|---|
3572968 | Musick et al. | Mar 1971 | A |
4257742 | Ogata et al. | Mar 1981 | A |
4401411 | Hisano et al. | Aug 1983 | A |
4784573 | Ress, Jr. | Nov 1988 | A |
5135354 | Novotny | Aug 1992 | A |
5228835 | Chlus | Jul 1993 | A |
5281097 | Wilson et al. | Jan 1994 | A |
5431543 | Brown et al. | Jul 1995 | A |
5827047 | Gonsor et al. | Oct 1998 | A |
6171058 | Stec | Jan 2001 | B1 |
6371727 | Stangeland et al. | Apr 2002 | B1 |
6951447 | Cherolis et al. | Oct 2005 | B2 |
7371048 | Downs et al. | May 2008 | B2 |
7374400 | Boswell | May 2008 | B2 |
20070041838 | Charbonneau et al. | Feb 2007 | A1 |
Number | Date | Country | |
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20100098547 A1 | Apr 2010 | US |