Patent Application
20090000101
1. Technical Field
The disclosure generally relates to gas turbine engine repair.
2. Description of the Related Art
During the life cycle of a gas turbine engine, various maintenance procedures are performed. Some of these maintenance procedures involve periodic inspections of components. Some of these inspections can be quite involved, including disassembly of various portions of the gas turbine that oftentimes requires removal of the gas turbine from an aircraft.
As is known, various components of a gas turbine can degrade over time. By way of example, flowpath components that are used to direct the flow of gas through the gas turbine can become abraded. This can be caused by dirt or other particles travelling with the flow of gas. Additionally, flowpath components can corrode, particularly when exposed to wet, salt-rich environments, such as can be experienced during over-ocean flights.
Conventionally, dimensional restoration of damaged metal components is accomplished in several manners. For instance, components can be restored by application of plasma spray, weld repair or plating.
Methods for repairing gas turbines are provided. In this regard, an exemplary embodiment of such a method comprises: identifying an affected area of a surface of a component of the gas turbine, the surface of the component defining a portion of a gas flow path through the gas turbine; applying an epoxy-based filler to the affected area; curing the epoxy-based filler; and blending the epoxy-based filler with the surface of the component.
Another exemplary embodiment of such a method comprises: removing a variable vane from an associated mount of the gas turbine; identifying an affected area of a surface of the mount; and repairing the affected area by applying an epoxy-based filler to the mount.
Still another exemplary embodiment of such a method comprises: removing a variable vane from a shroud of a compressor of the gas turbine, the shroud being formed of a Greek Ascoloy; visually identifying an affected area of a surface of the shroud, the surface defining a portion of a gas flow path through the gas turbine; applying an epoxy-based filler to the affected area such that the affected area is filled at least flush with the surface; curing the epoxy-based filler; and blending the epoxy-based filler with the surface of the shroud to dimensionally restore the surface.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
As will be described in greater detail here, methods for repairing gas turbines are provided. Specifically, the embodiments described herein involve the use of epoxy-based fillers, e.g., putty, paste and/or paint, for dimensional restoring components. By way of example, the components can include flowpath components, the surfaces of which can be used to define gas flow paths through the gas turbines.
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Portion 110 of the shroud is shown in greater detail in
Despite the ability to plasma spray or weld repair pitted surfaces, there may be many instances in which a less costly and time-consuming method may be appropriate. This is particularly so in cases where structural integrity is not an issue. That is, dimensional restoration is desired without the necessity of restoring the structural strength of the component surface. In these cases, epoxy-based fillers may be used to restore the affected surface to provide an improved flow path surface finish. Notably, if left unprotected, pitting can increase in size and depth with subsequent part use.
In this regard, epoxy-based fillers, such as high-temperature epoxy paste, high-temperature epoxy putty, and high-temperature epoxy paint can be used. Examples of such epoxy-based fillers are produced by Cotronics Corporation, such as those distributed under the trade names THERMEEZ™, DURABOND™ and DURALCO™.
The following figures schematically depict an embodiment of a method for repairing a gas turbine. Specifically,
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In
After filling, the epoxy-based filler is allowed to cure. Blending of the epoxy-based filler with the surface of the component is then undertaken. Although depicted as being accomplished with a power sander 126 in the embodiment of
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It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.
