Systems and methods for controlled vibratory peening

Abstract

Systems and methods for controlled vibratory peening are provided. The system includes a tub having a cavity configured to receive peening media, the cavity having a substantially horizontal bottom surface. A first vibration member and a second vibration member are connected to the tub, the first vibration member and the second vibration member being eccentrically weighted. A drive system is configured to rotate the first vibration member in a first rotational direction and configured to rotate the second vibration member in a second rotational direction opposite the first rotational direction. A component positioning member is configured to position a component in the cavity.

Description

SYSTEMS AND METHODS FOR CONTROLLED VIBRATORY PEENINGTechnical Field

[0001] The present disclosure relates to article treatment, and, in particular, to systems and methods for controlled vibratory peening.Background

[0002] Shot peening is a mechanical surface enhancement process aimed to improve the mechanical properties of components, primarily to increase fatigue strength and resistance to stress-corrosion cracking, and improve the component's productive life. In this process, small spherical shot particles (commonly manufactured from steel, ceramic, or glass) are bombarded at high velocity onto the surface of the material being treated. The impact of the shot particles induces compressive residual stresses on the surface layer of the material, which helps to counteract the tensile stresses, both resident and potentially generated when the component is put to use, that can lead to fatigue, cracking, and eventual failure. Shot peening is widely used in various industries, including aerospace, automotive, medical, and advanced manufacturing, when processing mission-critical and lifeenhancing metal components. Due to the impact of the shot particles, components that have been shot peened are typically left with a rough surface profile.

[0003] Vibratory finishing has been traditionally employed to "finish" or polish the surface of such shot peened components as a secondary process. Vibratory finishing is a mass finishing process used to deburr, descale, burnish, clean, and brighten large volumes of relatively small components. In this batch-type operation, specially shaped pellets of finishing media and the components are placed inside a vibrating tub. The vibratory action causes the media and parts to tumble and slide against each other, effectively removing burrs and producing a smooth finish. Various types of media such as ceramic, plastic, or metallic in a variety of shapes, and compounds may be used, depending on the application and material of the components. Vibratory finishing is commonly used for tasks rangingfrom rough deburring to high-gloss polishing. It offers advantages such as the ability to finish complex geometries and cavities where hand finishing would be impractical.

[0004] More recently, vibratory peening has been used to peen and finish components. In vibratory peening, also known as vibrapeening (or vibropeening) or vibrastrengthening (vibrostrengthening), the goal is to combine the benefits of shot peening and vibratory finishing. To date, however, there have been drawbacks in current approaches to vibrapeening / vibropeening.

[0005] Vibratory peening using circular tub motion technology has been developed in recent years. One such exemplary vibratory peening machine 20 is shown in FIG. 1A. The vibratory peening machine 20 includes an inverted hemicylindrical tub 24 that is at least partially filled with media along with flow- through lubricant / coolant. An example media unit 28 is shown in FIG. 1A. The media unit 28 has a generally spherical core with an enlarged mid-section.Referring again to FIG. 1A, a component 32 is positioned on a vertical shaft 36 that extends into the hemispherical tub 24 attached to a tub cover 40 on its underside. A vibratory motor 32 fitted with an imbalanced shaft acts to vibrate the hemispherical tub 24 to churn the media 28 in the hemispherical tub 24.

[0006] FIGS. 2A and 2B show another prior art circular tub motion vibratory peening machine 100 that includes an inverted hemicylindrical tub 104 supported by two rotating drive shafts 108. The drive shafts 108 are eccentrically weighted and rotate in the same direction (clockwise or counter-clockwise) to cause media contained in the tub to churn about one or more components positioned within.

[0007] These current vibratory peening machines are deficient in that they do not provide a measurable and consistent quality of shot peening and vibratory finishing.Summary

[0008] The present disclosure describes systems and methods which provideone or more efficient techniques to perform

[0009] In accordance with a first aspect of the present disclosure, there is provided a system for controlled vibratory peening, comprising: a tub having a cavity configured to receive peening media, the cavity having a substantially flat bottom surface; a first vibration member and a second vibration member connected to the tub, the first vibration member and the second vibration member being eccentrically weighted; a drive system configured to rotate the first vibration member in a first rotational direction, the drive system being configured to rotate the second vibration member in a second rotational direction opposite the first rotational direction; and a component positioning member configured to position a component in the cavity.

[0010] In some or all examples of the first aspect, the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

[0011] In some or all examples of the first aspect, the drive system is configured to rotate the first vibration member at a rotation speed and the second vibration member at the rotation speed.

[0012] In some or all examples of the first aspect, the drive system includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

[0013] In some or all examples of the first aspect, the cavity is at least partially filled with peening media along with flow-through lubricant fluid having coolant properties.

[0014] In some or all examples of the first aspect, the lubricant fluid includes a water-soluble lubricant.

[0015] In a second aspect of the present disclosure, there is provided a method for controlled vibratory peening, comprising: placing peening media in acavity configured to receive peening media in a tub, the cavity having a substantially flat bottom surface, the tub being supported by a first vibration member and a second vibration member, the first vibration member and the second vibration member being eccentrically weighted; positioning a component in the cavity; and driving the first vibration member to rotate in a first rotational direction and the second vibration member to rotate in a second rotational direction opposite the first rotational direction.

[0016] In some or all examples of the second aspect, the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

[0017] In some or all examples of the second aspect, the driving includes rotating the first vibration member at a rotation speed, and rotating the second vibration member at the rotation speed.

[0018] In some or all examples of the second aspect, the drive system includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

[0019] In some or all examples of the second aspect, the method includes at least partially filling the cavity with peening media along with flow-through lubricant fluid having coolant properties.

[0020] In some or all examples of the second aspect, the lubricant fluid includes a water-soluble lubricant.

[0021] In a third aspect of the present disclosure, there is provided a system for controlled vibratory peening, comprising: a tub having a cavity that is at least partially filled with peening media along with flow-through lubricant fluid having coolant properties; a vibration system configured to vibrate the tub; and a component positioning member configured to position a component in the cavity.

[0022] In some or all exemplary embodiments of the third aspect, thelubricant fluid includes a lubricant that is water soluble.

[0023] In a fourth aspect of the present disclosure, there is provided a method for controlled vibratory peening, comprising: placing peening media along with flow-through lubricant fluid having coolant properties in a cavity configured to receive peening media in a tub, the tub being connected to a vibration system configured to vibrate the tub; positioning a component in the cavity; and operating the vibration system to vibrate the tub.

[0024] In some or all exemplary embodiments of the fourth aspect, the lubricant fluid includes a lubricant that is water soluble.

[0025] In a fifth aspect of the present disclosure, there is provided a system for controlled vibratory peening, comprising: a tub having a cavity configured to receive peening media, the cavity having a bottom surface configured to apply a pushing force in a vertically upward direction along an entirety of the bottom surface when the tub is urged vertically upwards; a first vibration member and a second vibration member connected to the tub, the first vibration member and the second vibration member being eccentrically weighted; a drive system configured to rotate the first vibration member in a first rotational direction, the drive system being configured to rotate the second vibration member in a second rotational direction opposite the first rotational direction; and a component positioning member configured to position a component in the cavity.

[0026] In some or all exemplary embodiments of the fifth aspect, the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

[0027] In some or all exemplary embodiments of the fifth aspect, the drive system is configured to rotate the first vibration member at a rotation speed and the second vibration member at the rotation speed.

[0028] In some or all exemplary embodiments of the fifth aspect, the drivesystem includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

[0029] In some or all exemplary embodiments of the fifth aspect, the cavity is at least partially filled with peening media and a lubricant fluid having coolant properties.

[0030] In some or all exemplary embodiments of the fifth aspect, the lubricant fluid includes a water-soluble lubricant.

[0031] Other aspects and features of the present disclosure will become apparent to those of ordinary skill in the art upon review of the following description of specific implementations of the application in conjunction with the accompanying figures.Brief Description of the Drawings

[0032] Reference will now be made, by way of example, to the accompanying drawings which show example embodiments of the present application, and in which:

[0033] FIG. 1A is a schematic diagram illustrating a first prior art vibratory peening machine.

[0034] FIG. IB shows a media unit used in the vibratory peening machine of FIG. 1A.

[0035] FIGS. 2A and 2B show another prior art vibratory peening machine.

[0036] FIG. 3 is a perspective view of portions of an exemplary vibratory peening machine in accordance with an embodiment.

[0037] FIG. 4 is a schematic front elevation diagram of the exemplary vibratory peening machine of FIG. 3.

[0038] FIG. 5 is a schematic end view of the exemplary vibratory peeningmachine of FIG. 3.

[0039] FIG. 6 is a schematic top (plan) diagram of the exemplary vibratory peening machine of FIG. 3.

[0040] FIG. 7 shows an end view of the drive motor and shafts of the exemplary vibratory peening machine of FIG. 3.

[0041] FIG. 8 is a schematic diagram showing the direction of rotation of the shafts of FIG. 7.

[0042] FIG. 9 is a schematic diagram of the tub filled with a medium and having a component being treated therein.

[0043] FIGS. 10A to IOC show variations in the mass of media in the tub and the different possible depths of the component in the media.

[0044] Similar reference numerals may have been used in different figures to denote similar components. Unless otherwise specifically noted, articles depicted in the drawings are not necessarily drawn to scale.Detailed Description of Example Embodiments

[0045] The present disclosure is made with reference to the accompanying drawings, in which embodiments are shown. However, many different embodiments may be used, and thus the description should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same elements, and prime notation is used to indicate similar elements, operations or steps in alternative embodiments. Lastly, elements referred to in the singular may be plural and vice versa, except wherein indicated otherwise either explicitly or inherently by context.

[0046] A system 200 for controlled vibratory peening in accordance with someexemplary embodiments is shown in FIGS. 3 to 6 and 9. The system 200 includes a tub 204 that has a cavity 208 configured to receive peening media. The peening media can be of any suitable shape, such as spherical, planetary, etc. The tub 204 can be manufactured from hardened allow steel, and suitably lined with wearresistant material. A tub cover 212 selectively encloses the cavity 208 when moved towards the tub 204. A component positioning member 216 extends from a bottom surface of the tub cover 212 and has a component engagement portion 220 towards a distal end thereof. The component engagement portion 220 can be any suitable interface for securing the component to be treated to the component positioning member 216. Examples of suitable interfaces include a bolting interface, a clamping interface, a magnetic interface, and a fixtured interface. In some embodiments, the depth at which the component is positioned within the media is in the range of 10 to 25 centimeters, and can be selected by choosing an appropriately lengthened bar based on the amount of media / lubricant in the cavity 208 and the desired depth at which the component to be treated is to be positioned.

[0047] The tub 204 is connected to two rotating shafts 224 towards opposite lateral sides of the tub 204 that relatively freely rotate within apertures of flanges of the tub 204. The rotating shafts 224 are driven by a DC drive motor 228. In other embodiments, any suitable means for driving rotation of the rotation shafts can be employed. Each of the rotating shafts 224 is eccentrically weighted via one or more weights 232. The eccentricity of the rotating shafts 224 translates to vibration of the tub 204. The drive motor 228 is connected to the tub 204 and the two rotating shafts 224 to drive each at the same rotational speed X_Freq, the number of rotations per timeframe, and in opposite rotational directions. In addition, the position of the weight(s) on the first rotating shaft mirror the position of the weight(s) on the second rotating shaft. In particular embodiments, the rotational speed X_Freq can be varied in the range of 15 to 30 Hz, the weights X_Ecc can be varied in the range of 15 to 24 kilograms per shaft, and the mass of the media in the tub 204 is in the range of 300 to 500 kilograms.

[0048] FIGS. 10A to IOC show variations in the mass of media in the tub and the depth of the component in the media.

[0049] A set of airbags 236 support the tub 204 and enable relatively free vibration of the tub 204 relative to a surface S upon which the system 200 is located. In some embodiments, the pressure within the airbags 236 can be set within the range of 2 to 2.8 bars. By modifying the pressure in the airbags 236, the vibrations can be dampened more or less, and the transfer of vibrations to a base 244 of the system and floor can be reduced. The drive motor 228 is coupled to the tub 204 to facilitate vibration of the tub isolated from a surface S.

[0050] As can be seen in FIG. 9, the cavity 208 of the tub 204 has a substantially flat bottom surface that extends horizontally when the system 200 is configured for controlled vibratory peening. For purposes of this application, "substantially flat" shall mean planar or nearly planar apart from minor deviations in the surface. The bottom surface 240 of the tub 204 extends horizontally. The bottom surface is configured to apply a pushing force in a vertically upward direction along an entirety of the bottom surface when the tub is urged vertically upwards during vibration. This forces the media onto the component being treated.

[0051] In other configurations, it can be desirable to limit slopes along portions or the entirety of the bottom surface 240 of the cavity 208 to ten degrees at most from horizontal when the major plane of the bottom surface extends horizontally from horizontal when the major plane of the bottom surface extends horizontally. In some particular configurations, it can be desirable to limit slopes along portions or the entirety of the bottom surface 240 of the cavity 208 to 5 degrees at most from horizontal when the major plane of the bottom surface extends horizontally when the system 200 is configured for controlled vibratory peening. Instill other particular configurations, it can be desirable to limit slopes along portions or the entirety of the bottom surface 240 of the cavity 208 to 2 degrees at most from horizontal when the major plane of the bottom surface extends horizontally.

[0052] During preparation and operation of the system 200, the cavity 208 of the tub 204 is filled with media along with a flow-through lubricant / coolant. In one particular embodiment, the media is 3mm diameter AISI 1018 carbon steel balls, but, in other embodiments, other types of media can be employed. For example, media such as the satellite media shown in FIG. IB, spherical media (e.g., from 2 millimeter diameter up to 15 millimeter diameter), ball-cone media, etc. can be employed.

[0053] The lubricant includes coolant properties. It has been found through multiple tests that, by using a lubricant fluid for the media with coolant properties, both the quality of the finish and the strength of the component can be improved. In one embodiment, the lubricant used is Castrol® Syntilo 9828 that is water- soluble, enabling the lubricant to be mixed with water to transfer heat effectively. Other lubricants or lubricant mixtures with coolant properties will occur to those skilled in the art.

[0054] A component to be treated is secured to the component-positioning member 216. The cover 212 is then closed, and the drive motor 228 is turned on. The drive motor 228 causes the rotating shafts 224 to rotate in rotational directions counter to each other and at the same rotational speed. The eccentric weighting of the rotating shafts 224 cause the tub 204 to move upwards and downwards through inertia.

[0055] The opposing direction of rotation of the rotating shafts 224 causes the tub 204 to vibrate up and down vertically.

[0056] The substantially flat bottom surface of the cavity 208 of the tub 204 that is horizontal during use applies a relatively even upward force on the media as the rotating shafts 224 are being rotated. This enables consistent, repeatable results for the vibratory peening process.

[0057] FIG. 7 shows the drive motor 228 and the rotating shafts 224, and FIG. 8 shows a belt arrangement to drive the rotating shafts 224 to rotate inopposite rotational directions using the single drive motor 228.

[0058] All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devices and processes disclosed and shown herein may comprise a specific plurality of elements, the systems, devices and assemblies may be modified to comprise additional or fewer of such elements. Although several example embodiments are described herein, modifications, adaptations, and other implementations are possible. For example, substitutions, additions, or modifications may be made to the elements illustrated in the drawings, and the example methods described herein may be modified by substituting, reordering, or adding steps to the disclosed methods.

[0059] Features from one or more of the above-described embodiments may be selected to create alternate embodiments comprised of a sub-combination of features which may not be explicitly described above. In addition, features from one or more of the above-described embodiments may be selected and combined to create alternate embodiments comprised of a combination of features which may not be explicitly described above. Features suitable for such combinations and subcombinations would be readily apparent to persons skilled in the art upon review of the present disclosure as a whole.

[0060] In addition, numerous specific details are set forth to provide a thorough understanding of the example embodiments described herein. It will, however, be understood by those of ordinary skill in the art that the example embodiments described herein may be practiced without these specific details. Furthermore, well-known methods, procedures, and elements have not been described in detail so as not to obscure the example embodiments described herein. The subject matter described herein and in the recited claims intends to cover and embrace all suitable changes in technology.

[0061] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined bythe appended claims.

[0062] The present invention may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being only illustrative and not restrictive. The present disclosure intends to cover and embrace all suitable changes in technology. The scope of the present disclosure is, therefore, described by the appended claims rather than by the foregoing description. The scope of the claims should not be limited by the embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

Claims1. A system for controlled vibratory peening, comprising: a tub having a cavity configured to receive peening media, the cavity having a substantially flat bottom surface; a first vibration member and a second vibration member connected to the tub, the first vibration member and the second vibration member being eccentrically weighted; a drive system configured to rotate the first vibration member in a first rotational direction, the drive system being configured to rotate the second vibration member in a second rotational direction opposite the first rotational direction; and a component positioning member configured to position a component in the cavity.

2. The system of claim 1, wherein the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

3. The system of claim 2, wherein the drive system is configured to rotate the first vibration member at a rotation speed and the second vibration member at the rotation speed.

4. The system of claim 3, wherein the drive system includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

5. The system of claim 1, wherein the cavity is at least partially filled with peening media along with flow-through lubricant fluid having coolant properties.

6. The system of claim 5, wherein the lubricant fluid includes a water-soluble lubricant.

7. A method for controlled vibratory peening, comprising:placing peening media in a cavity configured to receive peening media in a tub, the cavity having a substantially flat bottom surface, the tub being connected to a first vibration member and a second vibration member, the first vibration member and the second vibration member being eccentrically weighted; positioning a component in the cavity; and driving the first vibration member to rotate in a first rotational direction and the second vibration member to rotate in a second rotational direction opposite the first rotational direction.

8. The method of claim 7, wherein the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

9. The method of claim 8, wherein the driving includes rotating the first vibration member at a rotation speed, and rotating the second vibration member at the rotation speed.

10. The method of claim 9, wherein the drive system includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

11. The method of claim 7, further comprising at least partially filling the cavity with peening media along with flow-through lubricant fluid having coolant properties.

12. The method of claim 11, wherein the lubricant fluid includes a water-soluble lubricant.

13. A system for controlled vibratory peening, comprising: a tub having a cavity that is at least partially filled with peening media along with flow-through lubricant fluid having coolant properties; a vibration system configured to vibrate the tub; and a component positioning member configured to position a component in the cavity.

14. The system of claim 13, wherein the lubricant fluid includes a lubricant that is water soluble.

15. A method for controlled vibratory peening, comprising: placing peening media and a lubricant fluid having coolant properties in a cavity configured to receive peening media in a tub, the tub being connected to a vibration system configured to vibrate the tub; positioning a component in the cavity; and operating the vibration system to vibrate the tub.

16. The method of claim 15, wherein the lubricant fluid includes a lubricant that is water soluble.

17. A system for controlled vibratory peening, comprising: a tub having a cavity configured to receive peening media, the cavity having a bottom surface configured to apply a pushing force in a vertically upward direction along an entirety of the bottom surface when the tub is urged vertically upwards; a first vibration member and a second vibration member connected to the tub, the first vibration member and the second vibration member being eccentrically weighted; a drive system configured to rotate the first vibration member in a first rotational direction, the drive system being configured to rotate the second vibration member in a second rotational direction opposite the first rotational direction; and a component positioning member configured to position a component in the cavity.

18. The system of claim 17, wherein the first vibration member is coupled to the tub towards a first lateral side of the tub and the second vibration member is coupled to the tub towards a second lateral side of the tub.

19. The system of claim 18, wherein the drive system is configured to rotate thefirst vibration member at a rotation speed and the second vibration member at the rotation speed.

20. The system of claim 19, wherein the drive system includes a drive connected to both the first vibration member and the second vibration member via a gearing system.

21. The system of claim 17, wherein the cavity is at least partially filled with peening media and a lubricant fluid having coolant properties.

22. The system of claim 21, wherein the lubricant fluid includes a water-soluble lubricant.

Images