Patent Description:
Fluid cavitation processing is used to treat the surfaces of manufactured parts. According to some techniques, fluid cavitation processes are used to peen the surface of a manufactured part to produce a compressive residual stress layer and modify the mechanical properties of the part. In other techniques, abrasive media is introduced into the fluid cavitation process to help finish and reduce the surface roughness of a manufactured part. For some complex parts or complex features in parts, such as those made using additive manufacturing techniques, accessing difficult-to-reach surfaces of the parts with cavitated fluid can be difficult.

In accordance with its abstract, <CIT> states a preventive maintenance method and apparatus for a structural member in a reactor pressure vessel for reducing a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.

<CIT> discloses a system for surface treating an internal surface of a part, the system comprising a tank within which the part is locatable, a fluid within the tank and capable of submersing the part when the part is located within the tank, a nozzle submersed in the fluid and configured to generate a stream of cavitated fluid directed in a first direction, and a deflection tool submersed in the fluid and comprising a deflection surface that redirects the stream of cavitated fluid from the first direction to a second direction, wherein the first direction is away from the internal surface of the part and the second direction is toward the internal surface of the part.

In accordance with its abstract, <CIT> states that in a surface treating method a fluid suction passage communicating with a fluid supply passage via only a narrowed portion is provided, so as to approximately concentrically surround the periphery of the fluid supply passage having the narrowed portion at one end thereof, and the sucking cavitation flow is generated at the direct downstream of the narrowed portion, by sucking the processing fluid into the fluid suction passage using a suction pump, as well as a surface treating is performed on the treated surface, by crushing the sucking cavitation flow approximately perpendicular to the treated surface.

In accordance with its abstract, <CIT> states a method for modifying an inner surface of a hole comprises injecting a water jet having a predetermined water pressure into a hole in a workpiece, in which the water jet consists of a low pressure water jet surrounding a high pressure water jet and cavity-producing bubbles. A flow control element having a reflection surface is arranged in the hole and the distance between the flow control element and the inner surface of the hole is not more than <NUM>. The high pressure water jet is injected and reflected on the reflection surface so that the water jet hits the inner surface of the hole. A double nozzle with a first outlet opening for the high pressure water jet and a second outlet opening surrounding the first opening for the low pressure water jet may be provided.

The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the shortcomings of fluid cavitation processing techniques for treating difficult-to-reach surfaces of manufactured parts, that have not yet been fully solved by currently available techniques. Accordingly, the subject matter of the present application has been developed to provide a fluid cavitation system and method for treating difficult-to-reach surfaces of manufactured parts that overcome at least some of the above-discussed shortcomings of prior art techniques.

Disclosed herein is a system for surface treating an internal surface of a part according to claim <NUM>.

The deflection surface may be flat, curved, concave, or convex.

The deflection tool may comprises a sphere and the deflection surface may be a surface of the sphere.

The deflection tool may further comprise at least two deflection surfaces.

The deflection surface may have a contour that complements a contour of the internal surface of the part.

The second direction may be perpendicular relative to the internal surface.

The part may comprise a rectangular-shaped pocket. The internal surface may comprise four sides each perpendicular to an adjacent side. The deflection tool may then be located within the rectangular-shaped pocket when the part is located within the tank. The deflection tool may comprise four deflection surfaces each configured to direct a portion of the stream of cavitated fluid towards a corresponding one of the four sides of the internal surface.

Malleability of the deflection surface of the deflection tool may be greater than malleability of the part.

The stream of cavitated fluid may be configured to, upon contacting the internal surface of the part, impart compressive stress to the part at the internal surface.

The system may further comprise abrasive media intermixed with the fluid within the tank. The stream of cavitated fluid may further comprise the abrasive media. The abrasive media of the stream of cavitated fluid may be configured to, upon contacting the internal surface of the part, reduce a roughness of the internal surface of the part.

Further disclosed herein is a method of surface treating an internal surface of a part according to claim <NUM>.

Impacting the internal surface of the part with the stream of cavitated fluid may comprise imparting a compressive stress to the part at the internal surface.

The method may further comprise introducing abrasive media into the stream of cavitated fluid. Impact the internal surface of the part with the stream of cavitated fluid may comprise impacting the internal surface of the part with the abrasive media introduced into the stream of cavitated fluid and reducing a surface roughness of the internal surface of the part with the abrasive media. The described features, structures, advantages, and/or characteristics of the subject matter of the presently claimed invention may be combined in any suitable manner in one or more embodiments and/or implementations. In the following description, numerous specific details are provided to impart a thorough understanding of embodiments of the subject matter of the present disclosure. One skilled in the relevant art will recognize that the subject matter of the presently claimed invention may be practiced without one or more of the specific features, details, components, materials, and/or methods of a particular example or implementation. In other instances, additional features and advantages may be recognized in certain embodiments and/or implementations that may not be present in all embodiments or implementations. Further, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the subject matter of the presently claimed invention. The features and advantages of the subject matter of the presently claimed invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the subject matter as set forth hereinafter.

In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which:.

Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the presently claimed invention. Appearances of the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. Similarly, the use of the term "implementation" means an implementation having a particular feature, structure, or characteristic described in connection with one or more embodiments of the presently claimed invention, however, absent an express correlation to indicate otherwise, an implementation may be associated with one or more embodiments.

Referring to <FIG>, according to some examples, described herein is a system <NUM> for surface treating an internal surface <NUM> of a part <NUM>. The system <NUM> includes a tank <NUM> within which the part <NUM> is locatable. The system <NUM> also includes a fluid <NUM> within the tank <NUM>. The fluid <NUM> is capable of submersing the part <NUM> when the part <NUM> is located within the tank <NUM>. The system <NUM> also includes a nozzle <NUM> submersed in the fluid <NUM>. The nozzle <NUM> is configured to generate a stream of cavitated fluid <NUM> directed in a first direction <NUM>. The system <NUM> additionally includes a deflection tool <NUM> submersed in the fluid <NUM>. The deflection tool <NUM> includes a deflection surface <NUM> that redirects the stream of cavitated fluid <NUM> from the first direction <NUM> to a second direction <NUM>. The first direction <NUM> is away from the internal surface <NUM> of the part <NUM> and the second direction <NUM> is toward the internal surface <NUM> of the part <NUM>.

The system <NUM> helps to intensify the fluid cavitation process (e.g., cavitation peening or cavitation abrasive surface finishing) on surfaces of the part <NUM> that are not within line-of-sight of the nozzle <NUM>. For example, in certain implementations, the nozzle <NUM> does not have line-of-sight with the internal surface <NUM> of the part <NUM> to be surface finished, when the part <NUM> is located within the tank <NUM>. However, in such implementations, the deflection surface <NUM> has line-of-sight with the internal surface <NUM> of the part <NUM> to be surface finished, when the part <NUM> is located within the tank <NUM>, which promotes directionality of the stream of cavitated fluid <NUM> to reach surfaces of the part <NUM> with an intensity that is not achievable without the deflection tool <NUM>.

The tank <NUM> is configured to contain the fluid <NUM>. Generally, the tank <NUM> includes a bottom and sides extending upwardly from the bottom. The sides are coupled to each other to laterally enclose the tank <NUM>. A top of the tank <NUM> is at least partially open, which allows the fluid <NUM> to be poured into the tank <NUM> and provides access for the nozzle <NUM> to be located within the fluid <NUM> in the tank <NUM>. The tank <NUM> is filled with enough fluid <NUM> to entirely submerse the part <NUM>, the deflection tool <NUM>, and the nozzle <NUM> in the fluid <NUM>. The fluid <NUM> is water in some examples and a fluid, other than water, in other examples.

The nozzle <NUM> forms part of a stream generation subsystem <NUM> of the system <NUM>. The stream generation subsystem <NUM> allows the nozzle <NUM> to generate the stream of cavitated fluid <NUM>. In certain examples, the stream generation subsystem <NUM> includes, in addition to the nozzle <NUM>, a fluid source <NUM>, a pump <NUM>, a valve <NUM>, and a series of conduits <NUM>. The conduits <NUM> fluidly couple together the fluid source <NUM>, the pump, the valve <NUM>, and the nozzle <NUM>. The pump <NUM> draws fluid <NUM> from the fluid source <NUM> and presents the fluid <NUM> to the valve <NUM>. The valve <NUM> is a pressure regulation valve that is configured to regulate the pressure of the fluid <NUM> before presenting the fluid <NUM> to the nozzle <NUM>. In some implementations, the valve <NUM> is an electronically-controlled valve that pressurizes the fluid <NUM> to a desired and adjustable pressure. The valve <NUM> facilitates control of the flow rate of the fluid <NUM> supplied to the nozzle <NUM>. The pressure and flow rate of the fluid <NUM> supplied to the nozzle <NUM> proportionally affects the energy of the stream of cavitated fluid <NUM>. Accordingly, the energy of the stream of cavitated fluid <NUM>, and thus the level of surface treatment, is adjustable via control of the valve <NUM>.

The nozzle <NUM> is any of various devices configured to introduce high-pressure fluid into the fluid <NUM> in a manner that produces a high-speed stream (e.g., cloud, jet, etc.) of cavitated fluid <NUM>. Cavitated fluid <NUM> is fluid that contains vapor cavities <NUM>, or small liquid-free bubbles, formed by a rapid change in pressure of the fluid <NUM> or other force acting on the fluid <NUM>. When the vapor cavities <NUM>, which contain vapor or air at a low pressure, are subjected to a higher pressure, the vapor cavities <NUM> implode, which generates a shockwave of fluid. The high pressure necessary to induce implosion of the vapor cavities <NUM> can be caused by the buildup of fluid pressure on the vapor cavities <NUM> after the vapor cavities <NUM> have impacted the surface of a part. The shockwaves induced by the implosion of the vapor cavities <NUM> is directed into the surface of the part. Depending on the energy of the shockwaves, the force of the shockwave can impart a compressive residual stress into the part. Such a process is known as fluid cavitation peening, which is depicted in <FIG>. Referring to <FIG>, reducing the energy of the stream of cavitated fluid <NUM> and introducing abrasive media <NUM> into the cavitated fluid <NUM>, by adding abrasive media <NUM> to the fluid <NUM> in the tank <NUM>, utilizes the shockwaves to drive the abrasive media <NUM> into the surface of the part, which smooths (i.e., reduces the roughness of) the surface by removing material from the surface. Although not shown in the systems <NUM> of <FIG>, in some examples, these systems <NUM> also include abrasive media <NUM> in the fluid <NUM> in the tank <NUM> to help reduce the roughness of the surface of the part by introducing the abrasive media <NUM> into the cavitated fluid <NUM>.

The nozzle <NUM>, in some examples, is thus configured to create a rapid change in pressure of the fluid <NUM> passing through the nozzle <NUM> so as to form vapor cavities <NUM> in the fluid <NUM> and transform the fluid <NUM> into the stream of cavitated fluid <NUM>.

Although not shown, the system <NUM> can include a multi-axis robot coupled to one or more components of the stream generation subsystem <NUM>, such as the nozzle <NUM>. The robot is configured to move and orientate the nozzle <NUM> within the tank <NUM>. In this manner, the nozzle <NUM> can be manipulated to direct the stream of cavitated fluid <NUM> in any of various directions (see, e.g., <FIG>) from any of various locations within the tank <NUM>. Notwithstanding the ability to manipulate the location and directionality of the stream of cavitated fluid <NUM> by moving and orientating the nozzle <NUM> in this manner, for some complex parts, such as those with internal surfaces, due to obstructions created by the part, it is not possible to sufficiently manipulate the nozzle <NUM> to direct the stream of cavitated fluid <NUM> from the nozzle <NUM> directly to the internal surfaces of the part. For this reason, the system <NUM> includes a deflection tool <NUM>, which allows the stream of cavitated fluid <NUM>, which initially is not aimed directly at the internal surfaces of a part, to be redirected to be aimed directly at the internal surfaces of the part. The deflection tool <NUM> of the system <NUM> is located within the tank <NUM> adjacent or coupled to the part <NUM> to be surface treated. More specifically, the deflection tool <NUM> is located and positioned to receive the stream of cavitated fluid <NUM>, from the nozzle <NUM>, at one or more deflection surfaces <NUM> of the deflection tool <NUM>, and to redirect the stream of cavitated fluid <NUM> at one or more internal surfaces <NUM> of the part <NUM>.

The part <NUM> has a complex shape. As used herein, a complex shape is any shape that has a recessed portion <NUM> or partially enclosed portion. The internal surface(s) <NUM> is the surface(s) defining the recessed portion <NUM> or partially enclosed portion of the part <NUM>. More specifically, in some examples, the internal surface(s) <NUM> of the part <NUM> are those surfaces that are not in line-of-sight with the nozzle <NUM>. Referring to <FIG>, for example, the recessed portion <NUM> is a side-slot in the part <NUM> that is open on a side of the part. The internal surface <NUM> defines the side-slot and includes portions that are mostly obstructed from line-of-sight of the nozzle <NUM>, even if the nozzle <NUM> were moved into a more angled position than that shown in <FIG>. Because portions of the internal surface <NUM> of the recessed portion <NUM> are obstructed from the nozzle <NUM>, the stream of cavitated fluid <NUM> generated by the nozzle <NUM> would not reach these obstructed portions of the internal surface <NUM> at all or with enough intensity to effectively surface treat the obstructed portions. More specifically, although the stream of cavitated fluid <NUM> includes some omni-directional flow of the vapor cavities <NUM>, and thus some surfaces of the part <NUM> not in line-of-sight with the nozzle <NUM> may be impacted by some of the vapor cavities <NUM>, the quantity or intensity of the vapor cavities <NUM> impacting these surfaces may be inefficient to effectively surface treat the surfaces.

The deflection surface <NUM> of the deflection tool <NUM> helps to redirect the stream of cavitated fluid <NUM> toward the internal surface <NUM>, which increases the quantity or intensity of the vapor cavities <NUM> impacting the internal surface <NUM>, thus improving the surface treatment of the internal surface <NUM>. Generally, in certain examples, the deflection surface <NUM> has a contour that complements a contour of the internal surface <NUM> of the part <NUM>. As used herein, in one example, the contour of the deflection surface <NUM> can be considered to complement the contour of the internal surface <NUM> of the part <NUM> when the deflection surface <NUM> is shaped in response to the shape of the internal surface <NUM> so that the stream of cavitated fluid <NUM> deflected off of the deflection surface <NUM> is directed towards the internal surface <NUM>.

Because the stream of cavitated fluid <NUM> includes omni-directional flow of the vapor cavities <NUM>, the stream expands or diverges as the stream moves away from the nozzle <NUM>. However, because the stream of cavitated fluid <NUM>, upon exit from the nozzle <NUM>, is directed in the same initial direction and an averaged flow of the vapor cavities <NUM> are in the initial direction, the stream of cavitated fluid <NUM> can be defined as flowing in the first direction <NUM>, indicated by a directional arrow. The first direction <NUM> is away from the internal surface <NUM> of the part <NUM> because the part <NUM> obstructs the vapor cavities <NUM> of the stream of cavitated fluid <NUM> from reaching the internal surface <NUM> or the first direction is offset from, diverges away from, or is aimed away from the internal surface <NUM>. The first direction <NUM> is aimed at the deflection surface <NUM> of the deflection tool <NUM>. Accordingly, at least part (e.g., all or a majority) of the stream of cavitated fluid <NUM> impacts the deflection surface <NUM>.

The deflection surface <NUM> redirects the stream of cavitated fluid <NUM> in the second direction <NUM>. Because the redirected stream of cavitated fluid <NUM> includes omni-directional flow of the vapor cavities <NUM>, the redirected stream widens or diverges as the stream moves away from the deflection surface <NUM>. However, because the redirected stream of cavitated fluid <NUM>, upon deflection from the deflection surface <NUM>, is directed in the same initial direction and an averaged flow of the vapor cavities <NUM> are in the initial direction, the redirected stream of cavitated fluid <NUM> can be defined as flowing in the second direction <NUM>, indicated by a directional arrow. The second direction <NUM> is toward the internal surface <NUM> of the part <NUM> because no portion of the part <NUM> obstructs the vapor cavities <NUM> of the redirected stream of cavitated fluid <NUM> from reaching the internal surface <NUM> or the second direction is aimed at the internal surface <NUM>.

The deflection tool <NUM> is made of a material that is less malleable than that of the part <NUM>. Accordingly, the stream of cavitated fluid <NUM> has less effect on the deflection tool <NUM> than on the part <NUM>. Moreover, in some examples, the material of the deflection tool <NUM> is selected, in view of the intensity of the stream of cavitated fluid <NUM>, to have a malleability low enough that the stream of cavitated fluid <NUM> has little to no effect on the deflection tool <NUM> as the stream impacts the deflection tool <NUM>. According to one example, the deflection tool <NUM> is made of a tool steel, such as <NUM> alloy steel and the like.

The deflection surface <NUM> is angled at an angle θ relative to the first direction <NUM>. The angle θ is more than zero-degrees, but less than <NUM>-degrees. The angle θ of the deflection surface <NUM> relative to the first direction <NUM> determines the angle of the second direction <NUM> relative to the first direction <NUM> or the angle of the second direction <NUM> relative to horizontal. Depending on the angle θ, the second direction <NUM> can be horizontal, downwardly directed, or upwardly directed. Accordingly, the deflection tool <NUM> is configured to have an angle θ that results in the second direction <NUM> being aimed at the internal surface <NUM> of the part <NUM>.

The part <NUM> is located in the tank <NUM> and is fixed to the tank <NUM>. In some examples, the part <NUM> is fixed to a fixture plate <NUM> or other surface that forms a bottom of the tank <NUM>. The fixture plate <NUM> provides a stable surface on which the part <NUM> can be fixed while the part <NUM> is surface treated. Fixation components, such as clamps, fasteners, brackets, straps, and the like can be used to fix the part <NUM> on the fixture plate <NUM>.

The deflection tool <NUM> is located within the tank <NUM> adjacent to or coupled to the part <NUM>. Generally, the deflection tool <NUM> is located within the tank <NUM>, relative to the part <NUM>, such that the deflection surface <NUM> receives the stream of cavitated fluid <NUM> and redirects the stream of cavitated fluid <NUM> toward the internal surface <NUM> of the part <NUM>. Referring to <FIG> and <FIG>, because the recessed portion <NUM> is a side-slot, the deflection tool <NUM> is a first deflection tool 144A located adjacent the part <NUM>. The deflection surface <NUM> of the first deflection tool 144A faces the recessed portion <NUM>. As used herein, adjacent means either spaced apart from, such as shown in <FIG>, or touching (e.g., abutting) an exterior surface of the part <NUM>.

Because the stream of cavitated fluid <NUM> is obstructed from entering most of the recessed portion <NUM> of the part <NUM> of <FIG> and <FIG>, the deflection tool 144A is located outside of and adjacent to the part <NUM>. Moreover, because the recessed portion <NUM> is on one side of the part <NUM>, the deflection tool 144A includes only one deflection surface <NUM>. Additionally, to maintain the breadth of coverage of the stream of cavitated fluid <NUM>, the deflection surface <NUM> of the deflection tool 144A is flat, which results in a redirected stream of cavitated fluid <NUM> that has a coverage at least at broad as the stream of cavitated fluid <NUM> impacting the deflection surface <NUM>. Generally, as the redirected stream of cavitated fluid <NUM> travels away from the deflection surface <NUM>, due to the omni-directional movement of the vapor cavities <NUM>, the redirected stream of cavitated fluid <NUM> expands or diverges.

Referring to <FIG>, the recessed portion <NUM> of the part <NUM> is a cavity, depression, slot, channel, or other recess formed in a top or upwardly facing surface of the part <NUM>. Because the recessed portion <NUM> of the part <NUM> of <FIG> is at least partially upwardly open, at least some portion of the stream of cavitated fluid <NUM> is capable of directly entering the recessed portion <NUM>. However, some portions of the internal surface <NUM> defining the recessed portion <NUM>, such as the internal surface defining the upright sidewalls of the part <NUM>, may be angled such that a direct impact with the stream of cavitated fluid <NUM> is not possible. Accordingly, in some examples, the internal surface(s) <NUM> of the part <NUM> are those surfaces that cannot receive a direct impact (e.g., where the first direction is aimed at the internal surface(s) <NUM>) from the stream of cavitated fluid <NUM> generated by the nozzle <NUM>. In such examples, directly impacting portions of the internal surface <NUM> with cavitated fluid that are not able to receive a direct impact from the stream of cavitated fluid <NUM> is accomplished by locating the deflection tool <NUM> within the recessed portion <NUM>. The deflection tool <NUM> is located on the part <NUM>, within the recessed portion <NUM>. In certain examples, the deflection tool <NUM> is coupled to the part <NUM>, such as via fasteners, clips, brackets, adhesives, and the like.

Additionally, to help redirect the stream of cavitated fluid <NUM> to multiple opposing portions of the internal surface <NUM>, the deflection tool <NUM> is a second deflection tool 144B that has at least two deflection surfaces <NUM>. Each of the deflection surfaces <NUM> defines an angle θ relative to the first direction <NUM> of the stream of cavitated fluid <NUM>. By aiming the stream of cavitated fluid <NUM> at the recessed portion <NUM>, and more specifically at the intersection of the at least two deflection surfaces <NUM> of the deflection tool 144B, a first portion of the stream of cavitated fluid <NUM> is redirected off of one of the deflection surfaces <NUM> of the deflection tool 144B toward a first portion of the internal surface <NUM> and second portion of the stream of cavitated fluid <NUM> is redirected off of another of the deflection surfaces <NUM> of the deflection tool 144B toward a second portion of the internal surface <NUM> (which, in the illustrated example of <FIG>, is opposite the first portion of the internal surface <NUM>). In this manner, a first redirected stream of cavitated fluid 130A directly impacts a desired portion of the internal surface <NUM> and a second redirected stream of cavitated fluid 130B directly impacts a different desired portion of the internal surface <NUM>.

Referring to <FIG>, to help redirect the stream of cavitated fluid <NUM> to even more opposing portions of the internal surface <NUM> of the recessed portion <NUM>, the deflection tool <NUM> is a third deflection tool 144C that has at least four deflection surfaces <NUM>. In some implementations, the third deflection tool 114C has is pyramid shaped. The recessed portion <NUM> of <FIG> is a pocket (e.g., a rectangular-shaped pocket) with four sides, each perpendicular to an adjacent side, and the part <NUM> can be a bathtub fitting. In certain examples, <FIG> can be considered a cross-section of <FIG>. Each of the deflection surfaces <NUM> defines an angle θ relative to the first direction <NUM> of the stream of cavitated fluid <NUM>. By aiming the stream of cavitated fluid <NUM> at the recessed portion <NUM>, and more specifically at the intersection of the at four deflection surfaces <NUM> of the third deflection tool 144C, four different portions of the stream of cavitated fluid <NUM> are redirected off of four different deflection surfaces <NUM> of the deflection tool 144B toward four different portions of the internal surface <NUM>. In this manner, a first redirected stream of cavitated fluid 130A directly impacts a first portion of the internal surface <NUM>, a second redirected stream of cavitated fluid 130B directly impacts a second portion of the internal surface <NUM>, a third redirected stream of cavitated fluid 130B directly impacts a third portion of the internal surface <NUM>, and a fourth redirected stream of cavitated fluid 130B directly impacts a fourth portion of the internal surface <NUM>. In some examples, as shown, the second direction <NUM> of a redirected stream is perpendicular relative to the portion of the internal surface being impacted, which improves the effectiveness of the surface treatment in certain implementations. However, in other examples, the second direction <NUM> of the redirected stream is not perpendicular relative to the portion of the internal surface being impacted.

In contrast to the deflection surfaces <NUM> of the first deflection tool 144A, the second deflection tool 144B, and the third deflection tool 144C, which are flat, in some examples, the deflection surface(s) <NUM> of the deflection tool <NUM> is curved. Curving the deflection surfaces <NUM> helps to broaden or narrow the coverage of the redirected stream of cavitated fluid <NUM>. As one example, referring to <FIG>, the deflection tool <NUM> is a fourth deflection tool 144D with a deflection surface <NUM> that is convex. When impacted by the stream of cavitated fluid <NUM>, the convexity of the deflection surface <NUM> redirects the stream of cavitated fluid <NUM> into a redirected stream of cavitated fluid <NUM> with a broader coverage than the stream of cavitated fluid <NUM> impacting the deflection surface <NUM>. In other words, the convexity of the deflection surface <NUM> magnifies the divergence of the redirected stream of cavitated fluid <NUM>, which can help to increase the portion of the internal surface <NUM> directly impacted by the cavitated fluid <NUM>. In some examples, the fourth deflection tool 144D comprises a sphere and the deflection surface <NUM> is the surface of the sphere. A sphere helps cavitated fluid <NUM> reach more of the internal surface <NUM>, particularly where the part <NUM> has a narrow opening into a larger internal cavity, such as the case with the part <NUM> of <FIG>. Although the fourth deflection tool 144D is a sphere with circular cross-sectional shapes, in other examples, the deflection tool <NUM> can be sphere-like, with a convex deflection surface and oblong or non-circular cross-sectional shapes, to produce a redirected stream of cavitated fluid <NUM> with an intensity that predictably varies across the redirected stream.

In contrast to the deflection surface <NUM> of the fourth deflection tool 144D, which is convex, in some examples, the deflection surface(s) of the deflection tool <NUM> is concave. As one example, referring to <FIG>, the deflection tool <NUM> is a fifth deflection tool 144E with a deflection surface <NUM> that is concave. When impacted by the stream of cavitated fluid <NUM>, the concavity of the deflection surface <NUM> redirects the stream of cavitated fluid <NUM> into a redirected stream of cavitated fluid 130A with a narrower coverage than the stream of cavitated fluid <NUM> impacting the deflection surface <NUM>. In other words, the concavity of the deflection surface <NUM> converges or concentrates the redirected stream of cavitated fluid <NUM>, which can help to increase the intensity of the cavitated fluid <NUM> at a focused portion of the internal surface <NUM>. In some examples, as shown, the fifth deflection tool 144E includes at least two deflection surfaces <NUM> each with a concave shape, which facilitates concentrated impacts of cavitated fluid <NUM> at two portions of the internal surface <NUM>.

Referring now to <FIG>, according to some examples, the orientation of the nozzle <NUM> is adjustable to adjust the first direction <NUM> of the stream of cavitated fluid <NUM>. Accordingly, as shown, the first direction <NUM> of the stream of cavitated fluid <NUM> is angled (at some angle between zero-degrees and <NUM>-degrees) relative to vertical, while the first direction <NUM> of the stream of cavitated fluid <NUM> of <FIG> is not angled relative to vertical (e.g., parallel to vertical). The system <NUM> of <FIG> is similar to that of <FIG> except to compensate for the angle of the first direction <NUM>, the angle γ of the deflection surface <NUM> of the sixth deflection tool 144F, relative to vertical, is different than that in <FIG>. In some examples, the angle γ of the deflection surface <NUM> of the sixth deflection tool 144F is such that the angle θ of the deflection surface <NUM> relative to the angled first direction <NUM> in <FIG> is the same as the angle θ of the deflection surface <NUM> relative to the non-angled first direction <NUM> in <FIG>. Moreover, in certain examples, the first direction <NUM> is angled and the sixth deflection tool 144F is configured such that the second direction <NUM> in <FIG> is the same direction as the second direction <NUM> in <FIG>. Accordingly, a system <NUM> where the first direction <NUM> is angled can still produce the same second direction <NUM> as a system <NUM> where the first direction <NUM> is not angled.

Referring to <FIG>, the system <NUM> is configured to treat the internal surface of a part <NUM> that has a tube-like shape. The recessed portion <NUM> of the part <NUM> in <FIG> is an elongate, circumferentially closed, conduit. Accessing the conduit and directing the stream of cavitated fluid <NUM> into the conduit, with an intensity sufficient to treat the internal surface <NUM> of the conduit, can be difficult. Accordingly, the deflection tool <NUM> of the system <NUM> is a seventh deflection tool <NUM> with a deflection surface <NUM> that is curved and convex, similar to the fourth deflection tool 144D. However, unlike the fourth deflection tool 144D, the deflection surface <NUM> is inwardly directed such that the seventh deflection tool <NUM> has a funnel-like shape. A narrow outlet portion <NUM> of the seventh deflection tool <NUM> is sized to be partially inserted into the conduit of the part <NUM> such that a wide inlet portion <NUM> of the seventh deflection tool <NUM> is external to the conduit. The nozzle <NUM> is located and oriented such that the first direction <NUM> is aimed into the wide inlet portion <NUM>. In this configuration, at least a portion of the stream of cavitated fluid <NUM> generated by the nozzle <NUM> is directed into the seventh deflection tool <NUM>. After entering the seventh deflection tool <NUM>, the stream of cavitated fluid <NUM> is redirected by the deflection surface <NUM>. The inwardly-facing convexity of the deflection surface <NUM> acts to concentrate or converge the stream of cavitated fluid <NUM> into a more narrow redirected stream of cavitated fluid <NUM>, which is introduced from the seventh deflection tool <NUM> into the conduit of the part <NUM> where it treats the internal surface <NUM> defining the conduit.

Referring to <FIG>, according to some examples, a method <NUM> of surface treating an internal surface <NUM> of a part <NUM> is disclosed herein. The method <NUM> includes (block <NUM>) directing the stream of cavitated fluid <NUM> in the first direction <NUM> away from the internal surface <NUM> of the part <NUM> and into contact with the deflection surface <NUM> of the deflection tool <NUM>. The method <NUM> also includes (block <NUM>) deflecting the stream of cavitated fluid <NUM> off of the deflection surface <NUM> in the second direction <NUM> toward the internal surface <NUM> of the part <NUM>. The method <NUM> additionally includes (block <NUM>) impacting the internal surface <NUM> of the part <NUM> with the stream of cavitated fluid <NUM> deflected off of the deflection surface <NUM>. In certain examples, the internal surface <NUM> is not within a line-of-sight of the nozzle <NUM> that generates the stream of cavitated fluid <NUM>.

The method <NUM> additionally includes, in some examples, selecting the deflection tool <NUM> and corresponding deflection surface <NUM> in response to at least one of the geometry of the part <NUM>, including the shape and location, on the part <NUM>, of the internal surface <NUM>, or the material of the part <NUM>. For example, for internal surfaces <NUM> that are harder to access, a deflection tool <NUM> with a deflection surface <NUM> that imparts a more drastic redirection of the stream of cavitated fluid <NUM> is desired. As another example, for parts <NUM> made of more malleable materials, a deflection tool <NUM> with imparts a less drastic redirection of the stream of cavitated fluid <NUM> is desired.

In some examples, the method <NUM> additionally includes determining an intensity of the stream of cavitated fluid <NUM> to achieve a desired surface treatment of the part <NUM>. Determining the intensity of the stream of cavitated fluid <NUM> can be based on one or more factors, such as the malleability of the part <NUM>, the surface roughness of the part <NUM>, the geometry of the part <NUM>, the desired surface roughness of the part <NUM>, and/or the desired residual stress level in the part <NUM>. The method <NUM> can further include positioning and orienting the part <NUM> and the selected deflection tool <NUM>, in the tank <NUM>, relative to each other. The method <NUM> also includes generating the stream of cavitated fluid <NUM> with the determined intensity and impacting the part with the stream of cavitated fluid <NUM> using the selected deflection tool <NUM>, at the desired position and orientation relative to the part <NUM>, for a corresponding period of time to achieve the desired surface treatment of the part <NUM>.

In certain examples of the method <NUM>, (block <NUM>) impacting the internal surface <NUM> of the part <NUM> with the stream of cavitated fluid <NUM> deflected off of the deflection surface <NUM> includes imparting a compressive stress to the part <NUM> at the internal surface <NUM>, such as is shown in <FIG>. Additionally, or alternatively, in some examples, the method <NUM> further includes introducing abrasive media <NUM> into the stream of cavitated fluid <NUM> and (block <NUM>) impacting the internal surface <NUM> of the part <NUM> with the stream of cavitated fluid <NUM> deflected off of the deflection surface <NUM> includes impacting the internal surface <NUM> of the part <NUM> with the abrasive media introduced into the stream of cavitated fluid <NUM> and reducing a surface roughness of the internal surface <NUM> of the part <NUM> with the abrasive media <NUM>, such as is shown in <FIG>. According to other examples of the method <NUM>, at least a portion of the deflection tool <NUM> is located within a recessed portion <NUM> of the part <NUM> and the stream of cavitated fluid <NUM> is directed at least partially into the recessed portion <NUM> of the part <NUM> in the first direction <NUM>.

In the above description, certain terms may be used such as "up," "down," "upper," "lower," "horizontal," "vertical," "left," "right," "over," "under" and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an "upper" surface can become a "lower" surface simply by turning the object over. Nevertheless, it is still the same object. Further, the terms "including," "comprising," "having," and variations thereof mean "including but not limited to" unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. Further, the term "plurality" can be defined as "at least two. " Moreover, unless otherwise noted, as defined herein a plurality of particular features does not necessarily mean every particular feature of an entire set or class of the particular features.

Additionally, instances in this specification where one element is "coupled" to another element can include direct and indirect coupling. Direct coupling can be defined as one element coupled to and in some contact with another element. Indirect coupling can be defined as coupling between two elements not in direct contact with each other, but having one or more additional elements between the coupled elements. Further, as used herein, securing one element to another element can include direct securing and indirect securing. Additionally, as used herein, "adjacent" does not necessarily denote contact. For example, one element can be adjacent another element without being in contact with that element.

As used herein, the phrase "at least one of', when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, "at least one of" means any combination of items or number of items may be used from the list, but not all of the items in the list may be required. For example, "at least one of item A, item B, and item C" may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, "at least one of item A, item B, and item C" may mean, for example, without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

The schematic flow chart diagrams included herein are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one exampleof the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

The present subject matter may be embodied in other specific forms without departing from the scope of the claims. The described embodiments are to be considered in all respects only as illustrative and not restrictive. angle θ of the deflection surface <NUM> relative to the non-angled first direction <NUM> in <FIG>. Moreover, in certain examples, the first direction <NUM> is angled and the sixth deflection tool 144F is configured such that the second direction <NUM> in <FIG> is the same direction as the second direction <NUM> in <FIG>. Accordingly, a system <NUM> where the first direction <NUM> is angled can still produce the same second direction <NUM> as a system <NUM> where the first direction <NUM> is not angled.

Claim 1:
A system (<NUM>) for surface treating an internal surface (<NUM>) of apart (<NUM>), the system (<NUM>) comprising:
a tank (<NUM>) within which the part (<NUM>) is locatable;
a fluid (<NUM>) within the tank (<NUM>) and capable of submersing the part (<NUM>) when the part (<NUM>) is located within the tank (<NUM>);
a nozzle (<NUM>) submersed in the fluid (<NUM>) and configured to generate a stream of cavitated fluid (<NUM>) directed in a first direction (<NUM>); and
a deflection tool (<NUM>) submersed in the fluid (<NUM>) and comprising a deflection surface (<NUM>) that redirects the stream of cavitated fluid (<NUM>) from the first direction (<NUM>) to a second direction (<NUM>), wherein the first direction (<NUM>) is away from the internal surface (<NUM>) of the part (<NUM>) and the second direction (<NUM>) is toward the internal surface (<NUM>) of the part (<NUM>), wherein:
the deflection tool (<NUM>) is configured to be fixed to the part (<NUM>) within a recessed portion (<NUM>) of the part (<NUM>) and the recessed portion (<NUM>) of the part defines the internal surface (<NUM>);
the nozzle (<NUM>) does not have line-of-sight with the internal surface (<NUM>) of the part (<NUM>) when the part (<NUM>) is located within the tank (<NUM>); and
the deflection surface (<NUM>) has line-of-sight with the internal surface (<NUM>) of the part (<NUM>) when the part (<NUM>) is located within the tank (<NUM>).