Patent Application
20070141261
The methods and apparatus described and/or illustrated herein relate generally to turbine engines, and more specifically to fabricating turbine engine components.
At least some known turbine engine components are coated with a metallic and/or ceramic coating, for example a thermal barrier coating (TBC) or a wear-resistant coating, to shield such components from high temperature gas flows generated within the engine. However, the application of a coating may sometimes adversely affect and/or limit the performance of some components exposed to the gas flow path. Accordingly, some components are at least partially masked before application of the coating such that the coating does not coat all or a portion of the component. For example, surfaces defined between adjacent seal teeth, which may be used with rotating seals within the engine, are sometimes masked to prevent the coating from coating such surfaces.
Some known turbine engine components are masked using an adhesive-backed tape, for example glass-filled masking tape. However, applying and removing tape may be time consuming and difficult, for example because of tight tolerances of the masked component or component portion, which may increase a cost and/or a cycle time of fabricating the component. For example, it may be difficult and/or time consuming to apply tape to surfaces defined between adjacent seal teeth, because of a size of spaces between adjacent teeth. Moreover, because some of the coating applied adjacent the masked component or component portion may overlap the tape, removal of the tape after the coating has been applied may cause the coating to chip, which may adversely affect and/or limit performance of the coating. Furthermore, tape used to mask a component or component portion may not be reusable once removed from the component or component portion, which may increase a cost of fabricating a plurality of the components. Some known turbine engine components are masked using rubber bands. For example, surfaces defined between adjacent seal teeth are sometimes masked with rubber bands. At least some known coatings are applied by spraying a powder onto the surface being coated. However, some particles of the sprayed powder may bounce off some known rubber bands such that the surface may not be evenly coated, which may adversely affect or limit performance of the coating. Furthermore, as with some known tape, some of the coating applied adjacent the masked component or component portion may overlap the rubber band, which may cause the coating to chip during removal of the rubber band. Moreover, some known rubber bands may lose some elasticity and/or shape such that, as with some known tape, the band may not be reusable once removed from the component or component portion.
In one aspect, an assembly includes a mask including a body and an opening within the body. The assembly also includes a component including a rotor and an extension extending radially outward from the rotor. The mask body is positioned with respect to the component such that at least a portion of the extension is received within the opening during rotation of the component relative to the mask. The mask body is positioned with respect to the component such that the body is configured to facilitate reducing deposition of a coating to a portion of the component adjacent the extension during application of the coating to at least a portion of the extension.
In another aspect, a method is provided for masking at least a portion of a component during application of a coating. The component includes a rotor and a plurality of extensions extending radially outward from the rotor along at least a portion of a circumference of the rotor and spaced axially along an axis of rotation of the rotor. The method includes positioning a mask having a plurality of openings between the component and a tool applying the coating such that at least a portion of each of the plurality of extensions is received within an opening of the plurality of mask body openings and such that at least a portion of the mask body extends through a channel defined between two adjacent extensions, rotating the rotor relative to the mask body, and applying a coating to at least a portion of each of the plurality of extensions such that the mask facilitates reducing contact between the coating and a surface of the channel defined between two adjacent extensions.
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Each mask body opening 56 may include any suitable size and/or shape, and/or any suitable configuration, orientation, arrangement, and/or location on mask body 54, that enable openings 56 to function as described herein. For example, each mask body opening 56 may include any suitable size and/or shape, and/or any suitable configuration, orientation, arrangement, and/or location on mask body 54, that enable each opening 56 to receive a portion of a corresponding seal tooth 36. Although each opening 56 may include other configurations, orientations, arrangements, and/or locations with respect to mask body 54, in the exemplary embodiment each opening 56 is an elongate opening extending along a portion of mask body length 58 between mask body end portion portions 60 and 62, and extending substantially parallel to length 58. Moreover, although each opening 56 may include other shapes, such as, but not limited to, an oval shape, in the exemplary embodiment each opening 56 is generally rectangular. A size and/or shape, and/or a configuration, orientation, arrangement, and/or location on mask body 54, of one or more openings 56 may be variably selected depend portioning on a type, size, and/or shape of seal 30 and/or any portion thereof. For example, a size and/or shape, and/or a configuration, orientation, arrangement, and/or location on mask body 54, of one or more openings 56 may be variably selected depend portioning on a size and/or shape of seal teeth 36 and/or channels 40.
Similarly, each mask body portion 70 may include any suitable size and/or shape, and/or any suitable configuration, orientation, arrangement, and/or location on mask body 54, that enable portions 70 to function as described herein. For example, each mask body portion 70 may include any suitable size and/or shape, and/or any suitable configuration, orientation, arrangement, and/or location on mask body 54, that enable each portion 70 to facilitate reducing application of a coating to channel radially inner surfaces 44, at least a portion of seal teeth sidewalls 42, and/or other portions of seal 30. Although each portion 70 may include other shapes, such as, but not limited to, a shape including a curved side, in the exemplary embodiment each portion 70 is generally rectangular. A size and/or shape, and/or a configuration, orientation, arrangement, and/or location on mask body 54, of one or more portions 70 may be variably selected depend portioning on a type, size, and/or shape of seal 30 and/or any portion thereof. For example, a size and/or shape, and/or a configuration, orientation, arrangement, and/or location on mask body 54, of one or more portions 70 may be variably selected depend portioning on a size and/or shape of seal teeth 36 and/or channels 40. In the exemplary embodiment, each mask body opening 56 is defined by a flange 72 extending generally outward from mask body 54. More specifically, each mask body opening 56 is defined by an outer end portion 74 of each flange 72. Flanges 72 may facilitate further reducing or eliminating application of a coating to a corresponding channel radially inner surface 44, at least a portion of seal teeth sidewalls 42, and/or other portions of seal 30. Flanges 72 may extend at generally any suitable angle with respect to mask body 54 that enable flanges 72 to function as described herein. For example, in the exemplary embodiment flanges 72 extend substantially obliquely with respect to mask body 54. In other embodiments, one or more flanges 72 extend substantially perpendicular to mask body 54. In some embodiments, mask body 54 does not include one or more flanges 72 extending outwardly therefrom such that one or more openings are not defined by a flange end portion 74.
To shield engine components from temperatures generated therein, components exposed to the temperatures may be coated with any suitable coating, such as, but not limited to, a thermal barrier coating (TBC) and/or a wear-resistant coating. The coating may either facilitate reducing heat transfer into the components, which may permit the engine to operate with an increased operating temperature for increasing an efficiency of the engine, and/or facilitate providing wear resistance to the components being coated. Although the coating may include any suitable material, some exemplary known coatings include, but are not limited to, a metallic material and/or a ceramic material. For example, some known coatings include a metallic bond layer applied to the component, and a ceramic layer applied to the metallic bond layer. Moreover, before some known coatings are applied, one or more surfaces of the component may be grit-blasted to facilitate adhesion of the coating to the surface(s). As described in more detail below, mask 50 facilitates reducing or eliminating contact between the coating and channel radially inner surfaces 44, at least a portion of seal teeth sidewalls 42, and/or other portions of seal 30 during application of the coating to seal 30.
To apply the coating to seal 30, mask 50 is positioned between tool 52 and seal 30. Mask 50 may be positioned between tool 52 and seal 30 in any location and/or orientation with respect to tool 52 and seal 30 that enables mask 50 to function as described herein. For example, in the exemplary embodiment mask body 54 is positioned such that a portion of each seal tooth 36 is received within a corresponding opening 56 and such that mask body portions 70 each extend through a corresponding channel 40 between adjacent seal teeth 36. Moreover, in the exemplary embodiment, and for example, mask 50 is positioned such that flanges 72 extend radially outward relative to seal rotor axis of rotation 34. Once mask 50 is positioned with respect to tool 52 and seal 30, the coating is applied to seal teeth 36 and/or other portions of seal 30 using any suitable method, process, structure, and/or means, such as, but not limited to, spraying the coating on seal 30 using a plasma torch. During application of the coating, seal 30 is rotated relative to mask 50 and tool 52. For example, in some embodiments the relative rotation is provided by rotating seal 30 about axis 34 when mask 50 and tool 52 are generally stationary. However, and for example, in some embodiments the relative rotation is provided by rotating mask 50 and tool 32 about an axis (e.g. axis 34) when seal 30 is generally stationary. As seal 30 rotates relative to mask 50 and tool 52, each of seal teeth 36 rotates within and relative to a corresponding mask body opening 56. As the coating is applied to seal 30, and for example seal teeth 36, mask body portions 70 facilitate reducing or eliminating contact between channel radially inner surfaces 44 and the coating, and thus may facilitate preventing the coating from being undesirably deposited on channel surfaces 44. In some embodiments, mask body portions 70 may also facilitate reducing or eliminating contact between the coating and at least a portion of seal teeth sidewalls 42 and/or other portions of seal 30, and may thus also facilitate preventing the coating from being undesirably deposited on at least a portion of sidewalls 42 and/or other portions of seal 30. As described above, flanges 72 may further facilitate reducing or eliminating contact between the coating and surfaces 44, at least a portion of sidewalls 42, and/or other portions of seal 30. In some embodiments, mask 50 is positioned with respect to seal 30 before grit-blasting seal 30 to facilitate shielding channel surfaces 44, at least a portion of seal teeth sidewalls 42, and/or other portions of seal 30 from the abrasive material sprayed during the grit blasting.
The above-described masks, assemblies, and/or methods may facilitate cost-effective and/or reliable fabrication of components. For example, the masks, assemblies, and/or methods described and/or illustrated herein may facilitate masking a plurality of seal sizes, shapes, types, configurations, and/or arrangements in an efficient and timely manner, which may result in reduced fabrication costs. Furthermore, and for example, the masks, assemblies, and/or methods described and/or illustrated herein may facilitate improving a quality and/or a repeatability of masking components in a cost-effective and reliable manner. For example, the masks, assemblies, and/or methods described and/or illustrated herein may facilitate reducing or eliminating chipping of the coating as compared to some known masks and/or methods thereof. Moreover, the masks described and/or illustrated herein may be reusable.
Although the masks, assemblies, and methods described and/or illustrated herein are described and/or illustrated with respect to turbine engine components, and more specifically to fabricating gas turbine engine components by masking all or a portion of a seal between adjacent seal teeth, practice of the masks, assemblies, and methods described and/or illustrated herein is not limited to masking a seal between adjacent seal teeth, masking gas turbine engine components, nor masking turbine engine components generally. Rather, the masks, assemblies, and methods described and/or illustrated herein are applicable to masking any portion of any object.
Exemplary embodiments of masks, assemblies, and methods are described and/or illustrated herein in detail. The masks, assemblies, and methods are not limited to the specific embodiments described herein, but rather, components of each mask and/or assembly, as well as steps of each method, may be utilized independently and separately from other components and steps described herein. Each component, and each method step, can also be used in combination with other components and/or method steps.
When introducing elements/components/etc. of the masks, assemblies, and methods described and/or illustrated herein, the articles “a”, “an”, “the” and “said” are intend portioned to mean that there are one or more of the element(s)/component(s)/etc. The terms “comprising”, “including” and “having” are intend portioned to be inclusive and mean that there may be additional element(s)/component(s)/etc. other than the listed element(s)/component(s)/etc.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
