Patent Description:
Manufacturing and repair processes for some types of components can include application of a coating material applied as a slurry. The slurry can include a metal mixture applied through spraying or dipping a portion of a solid component followed by a drying process to harden the slurry and bind the coating to the solid surface of the component.

The thickness of slurry material applied onto surfaces plays a role in the subsequent content diffusion into the coated parts. There is a need to maintain an appropriate range of coating thickness applied as a slurry on surfaces, particularly surfaces with complex geometries. Manual application of slurry coating can lead to uneven application of the coating on various surfaces of a part.

<CIT> discloses a spreading unit, having a shaper, for spreading viscous material, in particular sealing material, on a component, wherein the shaper has a shaping contour for the forming of the viscous material in the course of the spreading.

<CIT> discloses a scraping device for coating paper or cartons, comprising a plurality scraping laminates consisting of high wear-resistant material arranged in parallel.

<CIT> discloses a coating device for applying an insulating resin to a ceramic laminate. The coating device comprises a holding part for holding a ceramic laminate, a nozzle head part provided with a plurality of nozzles for discharging an insulation resin and a transfer means for moving the nozzle head part relative to the ceramic laminate along a laminating direction.

According to a first aspect there is provided a system for slurry coating leveling. The system includes a guide frame and a scrapper apparatus coupled to the guide frame. The scrapper apparatus includes a plurality of scrapper fingers aligned substantially parallel to each other. The system also includes a contour guide coupled to the scrapper fingers. The contour guide is configured to guide movement of the scrapper fingers across a surface of a component having a slurry coating. The scrapper fingers conform to a contour profile of the surface to level the slurry coating on the surface of the component. The scrapper fingers each comprise a guide probe that is offset from a scrapper finger end to define a desired slurry thickness.

Optionally, the guide probe of each of the scrapper fingers can be retractable.

Optionally, the system can include a controller configured to extend the guide probe of each of the scrapper fingers to perform an initial leveling of the slurry coating and retract the guide probe of each of the scrapper fingers prior to performing a final leveling of the slurry coating.

Optionally, the controller can be configured to wait for a predetermined hardening time between the initial leveling and the final leveling of the slurry coating.

Optionally, the contour guide can include a plurality of contour guide rails, each of the contour guide rails controlling a vertical position of at least one of the scrapper fingers as the scrapper apparatus moves with respect to the component.

Optionally, the contour guide can include a scrapper frame coupled to the guide frame and a spring bar coupled to the scrapper frame.

Optionally, each of the scrapper fingers can be respectively coupled by a spring to the spring bar to adjust positioning of the scrapper fingers to trace the contour profile of the surface of the component.

Optionally, the scrapper fingers can each include a scrapper finger end that is substantially flat.

Optionally, the system can include an enclosure, wherein the guide frame is moveable relative to the component within the enclosure.

According to another aspect there is provided a method for slurry coating leveling on a component. The method includes positioning a scrapper apparatus proximate to a component comprising a slurry coating, where the scrapper apparatus is coupled to a guide frame. The scrapper apparatus includes a plurality of scrapper fingers aligned substantially parallel to each other. The method also includes guiding movement of the scrapper fingers across a surface of the component comprising the slurry coating using a contour guide, where the scrapper fingers conform to a contour profile of the surface to level the slurry coating on the surface of the component. The scrapper fingers each comprise a guide probe that is offset from a scrapper finger end to define a desired slurry thickness.

Optionally, the method can include extending the guide probe of each of the scrapper fingers to perform an initial leveling of the slurry coating, and retracting the guide probe of each of the scrapper fingers prior to performing a final leveling of the slurry coating.

Optionally, the method can include waiting for a predetermined hardening time between the initial leveling and the final leveling of the slurry coating.

Optionally, the method can include adjusting positioning of the scrapper fingers to trace the contour profile of the surface of the component by the scrapper fingers, each of the scrapper fingers respectively coupled to a spring that is coupled to the spring bar.

Optionally, the method can include controlling movement of the guide frame relative to the component within an enclosure.

Certain exemplary embodiments will now be described in greater detail by way of example only and with reference to the accompanying drawings, with like elements being numbered alike, in which:.

Slurry coatings can be used in manufacturing and/or repair processes on one or more targeted surfaces of a component. Embodiments apply an excess level of a slurry coating and use a system for slurry coating leveling to ensure that a desired slurry coating thickness uniformly remains on component surfaces. The application of slurry coating in various stages of processing may occur in various forms, such as dipping, spraying, or other suitable methods. The slurry coating process can include multiple applications of slurry coating. An initial slurry coating application can be followed by scrapping the slurry coating while using guide probes to establish a desired slurry coating thickness. Once the slurry coating sets into a hardened form after an initial leveling, reapplication of the slurry coating can be performed to fill in gaps that are made by the guide probes. A second or final leveling can be performed after the reapplication of slurry without using the guide probes such that slurry coating fills in the gaps from the initial leveling. The final leveling can allow the slurry coating to remain between the gaps in previously set slurry coating while removing excess material from the top of the hardened slurry material. The use of multiple scrapper fingers in parallel that can have different vertical positions enables the desired slurry thickness to be established to conform to a contour profile of a surface of the component.

<FIG> shows a schematic view of a system <NUM> for slurry coating leveling. In the example of <FIG>, a slurry coating <NUM> can be applied on a surface <NUM> of a component <NUM>, and the component <NUM> can be placed within an enclosure <NUM> while the slurry coating <NUM> is partially viscous. The system <NUM> includes a scrapper apparatus <NUM> that includes a plurality of scrapper fingers <NUM> aligned substantially parallel to each other. The scrapper fingers <NUM> each include a guide probe <NUM> to establish a desired slurry thickness in the slurry coating <NUM>. The system <NUM> also includes a guide frame <NUM> coupled to the scrapper apparatus <NUM>. For example, the scrapper apparatus <NUM> can be coupled to the guide frame <NUM> by a contour guide <NUM>. In some embodiments, the guide frame <NUM> can be fixed onto the top of the enclosure <NUM>, and the contour guide <NUM> can connect to the guide frame <NUM> with the scrapper fingers <NUM> held by the contour guide <NUM>. The scrapper apparatus <NUM> can be moved relative to the component <NUM> or the component <NUM> can be moved relative to the scrapper apparatus <NUM>. For example, the guide frame <NUM> may be actuated using a motor to move the guide frame <NUM> and/or the contour guide <NUM>.

The system <NUM> can also include a controller <NUM> configured to control movement of the scrapper fingers <NUM> across the surface <NUM> of the component <NUM> including the slurry coating <NUM>, where the scrapper fingers <NUM> conform to a contour profile of the surface <NUM> to level the slurry coating <NUM> on the surface <NUM> of the component <NUM>. Before applying the slurry coating <NUM>, the scrapper fingers <NUM>, without the guide probes <NUM> extended, can be initially moved across the surface <NUM> of the component <NUM> to measure the exact location of the surface <NUM>, and the serial number of the component <NUM> can be recorded. The component <NUM> can be removed, slurry coated, and returned to the system <NUM>, which reads the serial number and runs the scrapper fingers <NUM> across a previously programmed offset of the surface <NUM> by a desired slurry thickness. A controller-based implementation may also adjust the desired slurry thickness at different locations on the surface <NUM>, such as tapering the slurry thickness proximate to a trailing edge to enhance aerodynamics.

The controller <NUM> can include a processing system <NUM> and a memory system <NUM>, where the memory system <NUM> stores executable instructions to configure the processing system <NUM> to perform a plurality of operations. The processing system <NUM> can include any type or combination of central processing unit (CPU), including one or more of: a microprocessor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like. The memory system <NUM> can store data and instructions that are executed by the processing system <NUM>. In embodiments, the memory system <NUM> may include random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic, or any other computer readable medium onto which is stored data and algorithms in a non-transitory form. The controller <NUM> can also include an input/output (I/O) interface <NUM> operable to interface with various components of the system <NUM> to sense, control, and communicate with components of <FIG> and other components (not depicted), such as a user interface.

As one example, the controller <NUM> may be configured to control the positioning of the scrapper apparatus <NUM> and/or the component <NUM>. The controller <NUM> may be configured to control the addition or removal of the slurry coating <NUM> on the surface <NUM> of the component <NUM>, such as through a spray, dip, or flow process. Alternatively, application of the slurry coating <NUM> is performed using a different apparatus and is not directly controlled by the controller <NUM>.

The scrapper fingers <NUM> can be individually actuated with assistance of a spring mechanism, which facilitates axial movement of the scrapper fingers <NUM> as depicted in the example of <FIG>. A contour guide <NUM> can be coupled to the scrapper fingers <NUM> to guide movement of the scrapper fingers <NUM>. The contour guide <NUM> can include a scrapper frame <NUM> coupled to the guide frame <NUM> and a spring bar <NUM> coupled to the scrapper frame <NUM>. Each of the scrapper fingers <NUM> can be respectively coupled by a spring <NUM> to the spring bar <NUM> to adjust positioning of the scrapper fingers <NUM> to trace the contour profile of the surface <NUM> of the component <NUM>.

<FIG> is a partial sectional view of an initial application of the slurry coating <NUM>. As can be seen in <FIG>, the surface <NUM> of the component <NUM> to be coated may have a complex contour, such as an airfoil, which adds to the complexity of establishing a uniform thickness of the slurry coating <NUM>.

<FIG> is a schematic view of an initial leveling of slurry coating <NUM> using the scrapper apparatus <NUM>. For example, the controller <NUM> of <FIG> can position the contour guide <NUM>. As the scrapper fingers <NUM> are positioned to contact the slurry coating <NUM>, the guide probes <NUM> on each of the scrapper fingers <NUM> can contact the surface <NUM> of the component <NUM> as depicted in <FIG>. Each guide probe <NUM> is offset from a scrapper finger end <NUM> to define a desired slurry thickness (T) as depicted in <FIG>. The curvature of the surface <NUM> can result in subsections of the slurry coating <NUM> that are slightly thicker or thinner than the desired slurry thickness (T). The scrapper fingers <NUM> can be sized to appropriate dimensions per the desired resolution for a given application. Opposite the spring end of the scrapper fingers <NUM> are contact points which interface with the surface <NUM> and/or the slurry coating <NUM>. The contact points include one or more guide probes <NUM> for initial levelling and a flat surface for finishing. Each of the scrapper finger ends <NUM> may be substantially flat and extend over a greater width than each of the guide probes <NUM>. For example, the width of each guide probe <NUM> may be about one-eighth of the width of each scrapper finger end <NUM>.

During initial leveling, the scrapper fingers <NUM> with the guide probes <NUM> can be traced along the surface <NUM> of the component <NUM> with the slurry coating <NUM>, such as slurry-coated turbine airfoils. The length of the guide probe <NUM> extending out from the scrapper finger end <NUM> of the scrapper finger <NUM> establishes the desired slurry thickness (T) and in some instances may be adjustable to support a range of thicknesses. Adjustments may occur in real-time during scrapping to dynamically adjust the desired slurry thickness (T) at specific locations on the component <NUM>. With the effects of gravity, spring loading of the springs <NUM> can adjust accordingly along the path on conically variable surfaces. While the guide probes <NUM> maintain contact with the component <NUM> to ensure the appropriate thickness, the flat surface of the scrapper finger end <NUM> levels the slurry coating <NUM> and pushes excess slurry along the movement path. The end result is a leveled application of the slurry coating <NUM> of the desired slurry thickness (T) separated into segments <NUM> (<FIG>), with gaps (or grooves) <NUM> between the segments <NUM> corresponding to the paths of the guide probes <NUM> through the slurry coating <NUM>.

The initial layer of slurry coating <NUM> may be processed or dried to create a different consistency as compared to fresh slurry coating. The slurry coating <NUM> can be reapplied over the segments <NUM> with gaps <NUM> to fill in the gaps <NUM> as depicted in <FIG>. During the finishing, as depicted in <FIG>, <FIG>, the scrapper fingers <NUM> without the guide probes <NUM> are traced along the slurry coating <NUM> as a final leveling. With the bulk of the desired slurry thickness completed, the applied slurry coating <NUM> fills the gaps <NUM> previously created by the guide probes <NUM>. The guide probes <NUM> may be detachable from the scrapper fingers <NUM> or may retract/extend from the scrapper fingers <NUM>. Alternatively, there can be separate systems <NUM> as part of a processing line, where one instance of system <NUM> includes scrapper fingers <NUM> with guide probes <NUM> and another instance of system <NUM> includes scrapper fingers <NUM> without guide probes <NUM>. Thus, the component <NUM> can be manually transferred or transferred through automation between the separate instances of the system <NUM> as needed.

<FIG> is a schematic view of a system <NUM> for slurry coating leveling. In the example of <FIG>, a slurry-coated component <NUM> can be placed within an enclosure <NUM> before the slurry has fully set. The system <NUM> includes a scrapper apparatus <NUM> that includes a plurality of scrapper fingers <NUM> aligned substantially parallel to each other. Rather than requiring multiple passes with and without guide probes <NUM> of <FIG>, the system <NUM> includes a contour guide <NUM> that establishes an individualized thickness per scrapper finger <NUM> to match complex contours of the slurry-coated component <NUM> as guide frame <NUM> slides within the enclosure <NUM>. In the example of <FIG>, the contour guide <NUM> includes a plurality of contour guide rails <NUM>, where each of the contour guide rails <NUM> controls a vertical position of at least one of the scrapper fingers <NUM> as the scrapper apparatus <NUM> moves with respect to the slurry-coated component <NUM>.

Turning to <FIG>, a flowchart shows a method <NUM> for leveling a slurry coating <NUM> on a component <NUM>. The method <NUM> of <FIG> is described with respect to <FIG> and may include additional steps beyond those depicted in <FIG>. The method <NUM> can be controlled by a control system, such as the controller <NUM> of <FIG>, or may be performed in part by one or more human operators. For instance, some portions of the method <NUM> can be manually performed depending on the amount of automation available. The method <NUM> is described primarily in reference to various examples from <FIG> for purposes of explanation, although it will be understood that variations and sub-combinations of previously described elements and/or additional elements can be used to implement the method <NUM>.

Initially, an amount of a slurry coating <NUM> can be applied to surface <NUM> of a component <NUM>, as illustrated in the example of <FIG>. At block <NUM>, the scrapper apparatus <NUM> can be positioned proximate to a component <NUM> including a slurry coating <NUM>, where the scrapper apparatus <NUM> is coupled to a guide frame <NUM>, and the scrapper apparatus <NUM> includes a plurality of scrapper fingers <NUM> aligned substantially parallel to each other.

At block <NUM>, movement of the scrapper fingers <NUM> across a surface of the component <NUM> can be guided using a contour guide <NUM>. Alternatively, contour guide <NUM> can be used. In some embodiments, the controller <NUM> can control movement of the scrapper fingers <NUM> across a surface <NUM> of the component <NUM> including the slurry coating <NUM>, where the scrapper fingers <NUM> conform to a contour profile of the surface <NUM> to level the slurry coating <NUM> on the surface <NUM> of the component <NUM>. During initial leveling, the guide probes <NUM> are used to establish the desired slurry thickness (T). At block <NUM>, the slurry coating <NUM> is allowed to set after the initial leveling. The drying and hardening of the slurry coating <NUM> can be accelerated using temperature, airflow, and/or other adjustments.

At block <NUM>, the slurry coating <NUM> is reapplied after the initial leveling to fill in the gaps <NUM> between segments <NUM>. Reapplication can be performed external to the system <NUM> or the system <NUM>. At block <NUM>, movement of the scrapper fingers <NUM> across the surface <NUM> of the component <NUM> can be guided without using the guide probes <NUM> during a final leveling of the slurry coating <NUM>. For example, the guide probes <NUM> can be retracted or detached from the scrapper fingers <NUM>. In embodiments, the guide probe <NUM> of each of the scrapper fingers <NUM> can be extended to perform initial leveling of the slurry coating <NUM> and retracted to perform the final leveling of the slurry coating <NUM>. The controller <NUM> can be configured to wait for a predetermined hardening time between the initial leveling and the final leveling of the slurry coating <NUM>.

Claim 1:
A system (<NUM>) for slurry coating leveling, the system comprising:
a guide frame (<NUM>);
a scrapper apparatus (<NUM>) coupled to the guide frame (<NUM>), the scrapper apparatus (<NUM>) comprising a plurality of scrapper fingers (<NUM>) aligned substantially parallel to each other; and
a contour guide (<NUM>) coupled to the scrapper fingers (<NUM>), the contour guide (<NUM>) configured to guide movement of the scrapper fingers (<NUM>) across a surface (<NUM>) of a component (<NUM>) comprising a slurry coating (<NUM>), wherein the scrapper fingers (<NUM>) conform to a contour profile of the surface (<NUM>) to level the slurry coating (<NUM>) on the surface (<NUM>) of the component (<NUM>),
characterised in that the scrapper fingers (<NUM>) each comprise a guide probe (<NUM>) that is offset from a scrapper finger end (<NUM>) to define a desired slurry thickness (T).