Patent Grant
9828857
The present disclosure relates to a gas turbine engine and, more particularly, to a repair or remanufacture procedure for a component thereof.
Gas turbine engines generally include a gas generator with a compressor section to pressurize an airflow, a combustor section to burn a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases. In an industrial gas turbine (IGT) engine, a core gas stream generated in the gas generator is passed through a power turbine section to produce mechanical work.
The core gas stream downstream of the combustor section may subject the turbine components to pressure gradients, temperature gradients, and vibrations that may result in thermal-mechanical fatigue cracks. Eventually, the turbine components may need to be replaced multiple times over the engine service life. Replacement of such components is relatively expensive such that there are often considerable economic incentives to repair these components.
An article of manufacture according to one disclosed non-limiting embodiment of the present disclosure includes an article having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in TABLE 1, and wherein X and Y are distances in inches which, when connected, define profile sections at each distance Z in inches to form a portion of a rotor blade.
A further embodiment of the present disclosure includes a rotor blade platform puck and a portion of a platform.
A further embodiment of the present disclosure includes, an electrical discharge machined (EDM) platform puck is.
A further embodiment of the present disclosure includes a platform puck brazed to the platform.
A further embodiment of the present disclosure includes a platform puck and the portion of a platform within an envelope of +/−.0.160 inches in a direction normal to any article surface location.
A further embodiment of the present disclosure includes an article shape within an envelope of +/−.0.160 inches in a direction normal to any article surface location.
A further embodiment of the present disclosure includes scaling, by a constant, of the Cartesian coordinate values of X, Y and Z set forth in TABLE 1.
A rotor blade according to another disclosed non-limiting embodiment of the present disclosure includes having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in TABLE 1, and wherein X and Y are distances in inches which, when connected, define profile sections at each distance Z in inches to form a platform puck brazed to a portion of a platform.
A rotor blade according to another disclosed non-limiting embodiment of the present disclosure includes a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in TABLE 1, and wherein X and Y are distances in inches which, when connected, define profile sections at each distance Z in inches define a repair assembly including a platform puck brazed to a portion of a platform, the Cartesian coordinate values of X, Y and Z set forth in TABLE 1 are scaled by a constant.
A further embodiment of the present disclosure includes a platform puck brazed to the platform only on a pressure side of the platform.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation of the invention will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.
Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows:
The compressor section 24, the combustor section 26, and the turbine section 28 are collectively referred to as a gas generator that is operable to drive the power turbine section 30. The power turbine section 30 drives an output shaft 34 to power a generator 36 or other system. In one disclosed non-limiting embodiment, the power turbine section 30 includes a free turbine with no physical connection between the gas generator and the power turbine section 30. The generated power is a thereby a result of mass flow capture by the otherwise free power turbine.
With reference to
The rotor assembly 66 includes an array of blades 84 (one shown in
Combustion gases produced in the combustor section 26 (indicated schematically by arrow C) expand in the turbine section 28 and produce pressure gradients, temperature gradients, and vibrations. The turbine components in the turbine section 28 are thereby subject to thermal-mechanical fatigue that, over time, may generate cracks in these components.
With reference to
Thermal-mechanical fatigue cracks may occur on the underplatform 110 and can be removed via machining. This machining, however, thins the platform 90, and applicant has determined that the frequency and amplitude of occurrence of such cracks resulting from use subsequent to such machining is related to the thickness of the platform 90. The thickness of the platform 90, in an exemplary embodiment may range from about 0.100-0.200 inches (2.5-5.1 mm), depending in part upon casting and/or previous repairs.
With reference to
Referring to
With reference back to
The puck 120 is plunged into the underplatform 110 to remove material from the puck 120 until both parts create a near perfect fit one to another. Such a near perfect fit enhances braze strength, as it is desired for braze faying surfaces to have a gap no larger than about 0.005″ (0.127 mm). That is, the puck 120 is initially cast and/or machined to be close to the dimension of the area of the underplatform 110, then subjected to the reverse EDM process to obtain a close-fitting gap therebetween. Trials have shown a finished gap of about 0.0005″-0.0045″ (0.0127-0.1143 mm).
Next, the puck 120 and the underplatform 110 area are weld prepared (step 206). Weld preparation includes, but is not limited to, for example, degreasing, fluoride-ion cleaning, grit blast, hydrogen furnace clean, vacuum clean and/or others.
Next, the EDM machined platform puck 120 is located in the blade underplatform 110 pocket and tack welded thereto (step 208). It should be appreciated that various methods may be alternatively or additionally provided to affix the puck 120 to the underplatform 110 so as to facilitate brazing (step 210).
A braze slurry is then applied around a perimeter of the puck 120 and subsequently brazed via the application of heat to the blade 84, puck 120, and braze slurry (step 210). The braze slurry flows over and around the puck 120 to join the puck 120 to the underplatform 110. Since brazing does not melt the base metal of the joint, brazing allows much tighter control over tolerances and produces a clean joint with minimal, if any, need for secondary finishing. Additionally, dissimilar metals and non-metals (i.e. metalized ceramics) can be brazed. That is, the puck 120 may be manufactured of a material dissimilar to that of the blade 84.
The braze slurry is readily received into the close finished gap interface between the platform puck 120 and the underplatform 110 via capillary action to provide an effective braze therebetween. That is, the reverse EDM interface provides a close-fitting interface that facilitates a high strength brazed interface and does not further reduce the thickness of the platform 90.
Finally, the finished braze B may be blended and coated to form a desired profile (step 212;
With reference to
The method 200 provides a repair to a small portion of the component to increase platform thickness with the remainder being identical to an OEM component. The Reverse EDM also facilitates a relatively rapid repair.
With reference to
The coordinate values given in TABLE 1 provide the nominal profile envelope for the repair assembly 130 including an exemplary platform puck 120 and at least a portion of the platform 90 of the blade 84. The portion of the platform 90 of the blade 84 generally includes at least a portion of the gas path surface 106 of the platform 90 and an undersurface 121 of the platform puck 120. That is, at least the gas path surface 106 and its relative Z-position with respect to the undersurface 121 of the platform puck 120 are included within the unique set of loci provided in TABLE 1. It should be appreciated that the portion of the platform 90 given in TABLE 1 may be of various sizes but generally encompasses at least a portion of the gas path surface 91 that is greater than the area of the platform puck 120 brazed to the underplatform 110 as described above and generally exclude fillet regions of the platform 90 that blends to the airfoil 92.
The TABLE 1 values below are generated and shown for determining the profile of the repair assembly 130 including the platform puck 120 and at least a portion of the platform 90. There are typical manufacturing tolerances as well as coatings, which should be accounted for in the actual profile of the platform puck 120 and at least a portion of the platform 90 within the repair assembly 130. Accordingly, the values for the profile given are for a nominal platform puck 120 and at least a portion of the platform 90. It will be appreciated that typical manufacturing tolerances, including any coating thicknesses, may bracket (are additive to, and subtractive from) the X, Y, and Z values. That is, a distance of about +/−0.160 inches in a direction normal to any location along the platform puck 120 and the at least a portion of the platform 90 defines a profile envelope therefor. For the most part, the puck 120 is generally XY oriented puck. In other words, a distance of about +/−0.160 inches in a direction normal to the surface corresponding to any coordinate defines a range of variation between measured coordinates on the actual surface at nominal temperature and ideal position of those coordinates, at the same temperature, as embodied by the invention.
A Cartesian coordinate system of X, Y and Z values given in TABLE 1 below defines a profile of the repair assembly 130 including the platform puck 120 and at least a portion of the platform 90. The coordinate values for the X, Y and Z coordinates are set forth in inches, although other units of dimensions may be used when the values are appropriately converted. The Cartesian coordinate system has orthogonally-related X, Y and Z axes. A positive X coordinate value extends tangentially in the direction of rotation of the rotor. The Y-axis lies parallel to the engine centerline, such as the rotary axis. A positive Y coordinate value is axial forward. A positive Z coordinate value is directed radially outward toward the static casing of the engine 20.
By defining X and Y coordinate values at selected locations in a Z direction normal to the X, Y plane, the profile of the repair assembly 130 including the platform puck 120 and at least a portion of the platform 90 are ascertained. These values represent the platform puck 120 and at least a portion of the platform 90 at ambient, non-operating conditions and are for an uncoated airfoil. Further, in this disclosed non-limiting embodiment, a reference Z-plane at 0, 0, 0 is defined by coordinate s R, B, G. The TABLE 1 values are thereby referenced with respect to the coordinate s R, B, G are:
R: X=0; Y=0; Z=0;
B: X=0; Y=4.375; Z=0; and
G: X=2.643; Y=0.734; Z=0
In this particular reference system, coordinate R is identified as an origin and is essentially located at an aft, pressure side corner, on the gas path side 91 of the platform 90. It should be appreciated that various other reference frames may be defined such that an equivalent Table for the X, Y, and Z coordinates may be correspondingly developed.
The X, Y and Z values given in the TABLE 1 below define a profile of the repair assembly 130 including the platform puck 120 and at least a portion of the platform 90 at various locations thereon. For example, the platform puck 120 and at least a portion of the platform 90, defined by the coordinate system of X, Y and Z values given in the TABLE 1 define a profile of the repair assembly 130 including the platform 90 as repaired with the puck 120 which has been EDM machined and brazed in place.
It will also be appreciated that the exemplary platform puck 120 and at least a portion of the platform 90 disclosed in TABLE 1 may be scaled up or down geometrically for use in other similar turbine blades. Consequently, the coordinate values set forth in the TABLE 1 may be scaled upwardly or downwardly such that the profile shape of the platform puck 120 and at least a portion of the platform 90 remains generally unchanged. For example, a scaled version of the coordinates in TABLE 1 would be represented by the X, Y and Z coordinates of TABLE 1 multiplied or divided by a constant.
Further, for example, the Z coordinate values of TABLE 1 may be multiplied or divided by a constant to accommodate thickness variations between the gas path surface 91 and a bottom surface 121 of the platform puck 120 (
The use of the terms “a,” “an,” “the,” and similar are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. It should be appreciated that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting.
Although the different non-limiting embodiments have specific illustrated components, the embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.
It should be appreciated that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be appreciated that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be appreciated that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5134774 | Porter | Aug 1992 | A |
| 5261480 | Wortmann et al. | Nov 1993 | A |
| 5895205 | Werner et al. | Apr 1999 | A |
| 6199746 | Dupree et al. | Mar 2001 | B1 |
| 6508000 | Burke et al. | Jan 2003 | B2 |
| 6908288 | Jackson et al. | Jun 2005 | B2 |
| 7449658 | Mielke | Nov 2008 | B2 |
| 7648341 | Lau | Jan 2010 | B2 |
| 20030034379 | Jackson et al. | Feb 2003 | A1 |
| 20080267775 | Grady et al. | Oct 2008 | A1 |
| 20090060714 | Moors | Mar 2009 | A1 |
| Number | Date | Country |
|---|---|---|
| 1940581 | Jul 2008 | EP |
| 2317075 | May 2011 | EP |
| 2361720 | Aug 2011 | EP |
| 2095589 | Oct 1982 | GB |
| Number | Date | Country | |
|---|---|---|---|
| 20160069196 A1 | Mar 2016 | US |
