The present disclosure relates to an arrangement for vibro-polishing one or more components. In particular, but not exclusively, the present disclosure relates to an arrangement and fixture for the containment of a component during a vibro-polishing process so as to prevent components, in use, from contacting one another.
Vibro-polishing is known for the surface improvement of metallic components such as, for example, aerofoils, discs, drums, bladed discs and bladed drums. In particular, vibro-polishing, also known as vibratory finishing, is typically used to deburr, radius, descale, burnish, clean and brighten components or parts which require such surface improvement.
In vibro-polishing, specially selected pellets, shot or tokens of media of a particular geometry, material and/or hardness are placed into an appropriately sized container. Components requiring treatment may then be placed into, or suspended within the media before the entire container, containing both the media and one or more components for treatment, is vibrated. In this way, vibro-polishing media may move relative to and/or against one or more surfaces of a component so as to rub or frictionally interact with the component in areas of the component accessible to the media. In particular, the abrasive nature of the material may cause a localised removal from the tips of any outwardly extending asperities, so smoothing the component or bringing about a material removal. As such, the media may interact with external or internal features of a component, such as holes or recesses, where active movement of media through or against the component is made possible.
The process may work solely through interaction of the vibro-polish media with the component, or may alternatively be assisted by combining the action of the vibro-polish media with a further chemically-based medium to at least partially assist in the material removal process. In such an instance, the process may be referred to as chemical vibro-polishing, or CVP. Such fluids may alternatively aid in lubricating the media or component, so aiding in the provision of a gentle removal process and/or enhanced longevity of the vibro-polish media. Additionally or alternatively, the chemically-based medium may instead aid in at least partially breaking down a surface oxide or surface layer of the component, thus assisting in material removal. Thus, the process may be either wet or dry.
In use, the container is commonly vibrated by an eccentric, rotating weight shaking the container in a circular path. In such an action, and upon rotation of the weight, the entire load is lifted up at an angle and is subsequently released such that the container may return to its resting position, thus defining an amplitude and frequency of vibration. In such a movement, the container returns to an upward position applying an upward and angular force, so causing a shearing action such that the part and media may rub against one another. Due to relative movement between the media and the component, it is also known that the larger the pellets, shot or tokens comprised within the vibro-polishing media, the faster the cutting action, and the quicker the rate of material removal.
Despite vibro-polishing being a known process, little research has been conducted into refining methods for supporting the component during processing or advancing manufacturing processes. In accordance with the above, there are a number of associated problems and known disadvantages with the presently available methods of vibro-polishing which render the process unsuitable for certain applications. Accordingly, fixed processes only allow a specific number of components to be attached to a fixture, thus leading to reduced efficiency for a large number of small components. For this reason, fixed processes are predominantly associated with the treatment of large components. The process also requires a large amount of processing time in order to mask components, clamp components and subsequently remove components from the fixture.
Traditional free flow polishing methods are also associated with drawbacks including increased cycle time, variation of material removal between components and/or treatment locations, for example, between the inner and outer vanes on cluster vanes, and the potential for component interaction during processing. Furthermore, modified ‘fixed’ vibro-polishing methods provide certain disadvantages, including high cost of fixturing and component masking, large amounts of processing time in order to mask components, clamp components and subsequently remove components from the fixture, high noise levels due to transfer of vibrations from the component to the fixture, and health and safety risks due to the localised thinning of the fixture, giving rise to knife-like sharp edges as processing continues.
It would therefore be advantageous to provide an improved fixture and arrangement for the vibro-polishing of a component without the aforementioned disadvantages.
According to a first aspect, there is provided an arrangement for vibro-polishing one or more components, the arrangement comprising a container for containing vibro-polishing media, an agitator to agitate the vibro-polishing media relative to the container, one or more partitions extending substantially across the container so as to provide two or more sectors, and, a fixture comprising at least one member which extends around one or more components for insertion into the vibro-polishing media, each member defining an opening which is sized to prevent any further fixture or partition from contacting the or each component.
Thus, in this way, the arrangement prevents, in use, further components and/or partitions from contacting the component comprised within the fixture. Thus, the arrangement provides, in use, continuous flow of vibro-polishing media over the surface of the component.
Thus, the arrangement provides ability, in use, to segregate components comprised within respective fixtures by placing each component in a different sector of the container. According to a second aspect, there is provided an arrangement for vibro-polishing one or more components, the arrangement comprising a container for containing vibro-polishing media, an agitator to agitate the vibro-polishing media relative to the container and, a fixture comprising at least one member which extends around one or more components for insertion into the vibro-polishing media to prevent any further fixture or partition from contacting the or each component.
According to a third aspect, there is provided an arrangement for vibro-polishing one or more components, the arrangement comprising a container for containing vibro-polishing media, a fixture comprising at least one barrier which extends around one or more components for insertion into the vibro-polishing media to prevent any further fixture or partition from contacting the or each component.
Optionally, each member may comprise an arm. The member may be referred to as a barrier.
Thus, in this way, the arm may be either disassembled or removed from the fixture. Thus, the arm may be of reduced cross-section relative to the fixture. As such, the arm may provide minimal resistance to vibro-polishing media flowing around the respective parts of the fixture before flowing over the surface of the component.
Optionally, the depth of the or each partition may be at least substantially equal to the depth of the vibro-polishing media within the container.
Thus, in this way, each partition may encapsulate the entire sector.
Optionally, the or each partition may comprise one or more openings.
Thus, in this way, one or more of the vibro-polishing media components may be allowed to freely flow between the two or more respective sectors.
Optionally, the vibro-polishing media may comprise one or more solid components.
Thus, in this way, the vibro-polishing media may provide one or more of a cutting, abrasive or lapping action through interaction of the or each solid component comprised within the vibro-polishing media with the component for treatment. More regularly, the vibro-polishing media may comprise many such solid components, thus improving interaction between the component for treatment and the solid components comprised within the vibro-polishing media. Accordingly, the rate of vibro-polishing is improved relative to the number of solid components comprised within the vibro-polishing media.
It will also be appreciated that any such media providing one or more of a cutting, abrasive or lapping action through interaction of the or each solid component comprised within the vibro-polishing media with the component for treatment may be suitable for use. Thus, semi-solid or porous materials may also be used.
Optionally, the vibro-polishing media may comprise one or more liquid components.
Thus, in this way, the liquid component may provide added either lubrication and/or chemical assistance to aid in the vibro-polishing process.
Optionally, the or each opening within the or each partition may be larger than the or each vibro-polishing media component to allow the vibro-polishing media to traverse between partitioned sections.
Thus, in this way, vibro-polishing media may freely flow between the two or more respective sectors, the partition providing minimal resistance to vibro-polishing media flowing around the respective parts of the partition.
Optionally, the or each opening within the or each partition may be sized to prevent the or each fixture from traversing between partitioned sections.
Thus, in this way, whilst vibro-polishing media may freely flow between the two or more respective sectors, the openings are sized to prevent the or each fixture from traversing between partitioned sections. Thus, each fixture is maintained, in use, in the sector it was placed in.
Optionally, the or each partition may comprise a mesh.
Thus, in this way, the mesh is configured to provide minimal resistance to vibro-polishing media flowing around the respective parts of the mesh, whilst providing the structural integrity to prevent the fixture from traversing between partitioned sections.
Optionally, the or each partition may be arranged within the container so as to rotate, in use, within the vibro-polishing media.
Thus, in this way, the vibro-polishing process may be assisted by the partitions rotating, and thus providing an at least partially drag assisted vibro-polishing process.
The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the above aspects may be applied mutatis mutandis to any other aspect. Furthermore except where mutually exclusive any feature described herein may be applied to any aspect and/or combined with any other feature described herein.
Examples will now be described by way of example only, with reference to the Figures, in which:
With reference to
The gas turbine engine 10 works in the conventional manner so that air entering the intake 12 is accelerated by the fan 13 to produce two air flows: a first air flow into the intermediate pressure compressor 14 and a second air flow which passes through a bypass duct 22 to provide propulsive thrust. The intermediate pressure compressor 14 compresses the air flow directed into it before delivering that air to the high pressure compressor 15 where further compression takes place.
The compressed air exhausted from the high-pressure compressor 15 is directed into the combustion equipment 16 where it is mixed with fuel and the mixture combusted. The resultant hot combustion products then expand through, and thereby drive the high, intermediate and low-pressure turbines 17, 18, 19 before being exhausted through the nozzle 20 to provide additional propulsive thrust. The high 17, intermediate 18 and low 19 pressure turbines drive respectively the high pressure compressor 15, intermediate pressure compressor 14 and fan 13, each by suitable interconnecting shaft.
Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. By way of example such engines may have an alternative number of interconnecting shafts (e.g. two) and/or an alternative number of compressors and/or turbines. Further the engine may comprise a gearbox provided in the drive train from a turbine to a compressor and/or fan.
As part of the manufacturing stage of a number of components comprised within the assembled gas turbine engine 10 such as, for example each of the components used in the assembly of the propulsive fan 13, intermediate pressure compressor 14, high-pressure compressor 15, combustion equipment 16, high-pressure turbine 17, intermediate pressure turbine 18, low-pressure turbine 19 and an exhaust nozzle 20. It will also be appreciated that any such appropriately sized component requiring surface improvement may be treated by using any number of processes or surface improvement/processing methods during manufacture and/or repair. One such process may include vibro-polishing, in particular vibro-polishing using the arrangement as shown in
Also shown, in one example, are two securing portions 38, each securing portion 38 locating within a plurality of channels 40 within the radially outer surface of each masking unit 36. In particular, although the securing portions 38 are shown in
As shown in
In a further example, the or each arm 44 may be continuous and/or form a helix around the component. In yet further examples, the or each arm 44 may extend at least substantially around the component, or the arms and/or connectors 42 may be manufactured from a single component. Thus, the or each arm 44 and/or connecting means 42, 46 may be either resilient or compliant to allow fitment to the component. It will also be appreciated that the or each means of connection 42, 46 may be located elsewhere in the arrangement, such as, for example, on the arms 44 themselves.
In a further example, it may be envisaged that two or more arms 44 be used to connect each connecting assembly, the exact number of arms 44 used depending on, for example, the degree of structural integrity required and the shape and/or complexity of the component to be treated. In a yet further example, one or more arms 44 of extended width or geometry may be envisioned for use in such an arrangement, the or each of the arms 44 being moulded or sculptured to encompass each of said components.
The number of the arms 44, securing portions 38 and connectors 42 used within each fixture 30 vary in one or more of shape, number or size to increase or decrease the circumferential spacing between one or more arms 44 of the assembled fixture 30. In this way, one or more of the profile, size or shape of one or more of the arms 44 varies according to requirements to increase or decrease either or both of the radial spacing between the arms of the assembled fixture 30 and the component, or the radius of the assembled fixture 30. This ensures that the component is sufficiently contained by the fixture 30.
The circumferential spacing between the or each arm of the assembled fixture 30 is equal to or less than the radius of the fixture 30, measured from the axis of rotation of the fixture 30. The fixture 30 may comprise one or more arms helically wound around the component. Alternatively, the fixture 30 may comprise four or more arms 44. The arms may be evenly or disparately spaced. Smaller spacing between the arms 44 may be required around a particularly sensitive feature or location upon the component. By reducing the spacing of the arms, the number of arms 44 may increase.
The diameter of the assembled fixture 30 may be equal to or greater than the largest diameter of the component, measured through the components axis of rotation. The assembled fixture 30 may be spherical and is arranged to fully contain the component.
Referring now to
By reducing the size of the spacing between the or each arm 44, or increasing the radial spacing between the arms 44 and the component, the fixture 30 prevents a further similarly sized fixture 30 or component from penetrating and contacting the component when two or more fixtures 30 mesh or interact. In this way, the component is prevented, in use, from contacting a further component.
Preventing component contact refers to reducing the likelihood of contact of two or more components during the vibro-polish process. In some examples, preventing component contact may be dependent on the angle of approach of one fixture relative to another, such that a component can only contact one or more further components when approaching from a particular angle. In further examples, such prevention may wholly prevent a component from contacting one or more further components when approaching from any angle.
In some examples, the opening, that is the spacing between the one or more arms 44, is sized so as to be sufficiently small to prevent a sufficient quantity of one or more of the fixture 30 and component from meshing with or penetrating the extremity of a further fixture to the extent that two or more components physically interact. In some examples, the circumferential spacing between the or each arm 44 of the assembled fixture 30 is equal to or less than the radius of the fixture 30, measured from the axis of rotation of the fixture 30. By preventing component contact during use, the likelihood and/or risk of either damage to the component or uneven surface treatment during the vibro-polishing process is substantially reduced.
In a further example, preventing component contact may refer to reducing the likelihood of an arm 44 or a partition contacting a further component during the vibro-polish process. In some examples, preventing arm 44 or partition contact with a component may be dependent on the angle of approach of one fixture relative to another, such that an arm 44 or partition can only contact one or more further components when approaching from a particular angle. In further examples, such prevention may wholly prevent an arm 44 or partition from contacting one or more further components when approaching from any angle.
In some examples, the opening, that is the spacing between the one or more arms 44, is sized so as to be sufficiently small to prevent a sufficient quantity of one or more of the fixture 30 and component from meshing with or penetrating the extremity of a further fixture 30 to the extent that one or more arms 44 of the fixture physically interact with the component. In some examples, the circumferential spacing between the or each arm of the assembled fixture 30 is equal to or less than the radius of the fixture 30, measured from the axis of rotation of the fixture 30. By preventing the fixture 30 from contacting the component during use, the likelihood and/or risk of either damage to the component or uneven surface treatment during the vibro-polishing process is substantially reduced.
In the example shown in
Similarly, the or each securing portion 38 is most regularly constructed of a moulded polymeric or elastomeric material, such as, for example, polyurethane. However, it will be appreciated that any such further plastics, composite, metallic, or coated metallic material may be used. In a further example, the means of attachment 42, 46 of the or each securing portion 38 to the or each arm 44 may, in one example, be comprised of a material which is different to the body of the connector. In particular, the means of attachment 42, 46 may be comprised of a metallic or polymeric material, or any such material with sufficient mechanical properties to support a mechanical attachment or assembly for the attachment of the arms 44 to the securing portion, or in a further example, the masking unit 36.
The or each arm 44 may, in one example, be constructed of a shaped steel structure coated with a polymeric or elastomeric material, such as, for example, polyurethane. However, it will be appreciated that any such further plastics, composite, metallic, or coated metallic material may be used. In a yet further example, the means of mechanical attachment to the securing portions 42, 46 may additionally be comprised of a material which is different to the body of the or each arm 44, the means of mechanical attachment 42, 46 being comprised of a metallic or polymeric material, or any such material with sufficient mechanical properties to support a mechanical attachment or assembly appropriate for the attachment of the or each arm 44 to the connectors 42, 46.
Referring again to
In a further example, the specific number and spacing of the members 72, 74 comprised within the partition 66 may depend on one or more of the size and shape of the component 50, including the assembled fixture 30 and masking arrangement 32. In instances where a smaller component is to be processed, there will be a need for either the specific number and spacing 76 of the members 72, 74 to be modified accordingly. Thus, spacing 76 of the members 72, 74 may be reduced to provide smaller holes, or a finer cage, net, or mesh-like structure 68.
In a further example, a generic partition 66 may be used which comprises openings 76 or holes smaller than the assembled fixture 30 and masking arrangement 32 for the containment of the smallest component to be processed, or a minimum component sizing. Thus, the partition 66 may be used for both large and small components during the vibro-polishing process. Thus, through the use of a partition 66 with smaller or finer spacing 76 and/or structure, dissimilar components of both large and small sizing may be processed within the same container 60. In a yet further example, through the use of a partition 66 with appropriately sized opening 76 and/or spaced structure, dissimilar components of both large and small sizing may be processed within the same container 60, but within separate partitioned sections. In a yet further example, through use of the previously described appropriately sized opening 76 and/or spaced structure, dissimilar components of both large and small sizing may be processed within the same portioned section.
In accordance with the previously described examples, it will be appreciated that decreasing the spacing size of the or each opening 76, thus decreasing the size of the holes 76, or increasing the number of vertical and/or horizontal members 72, 74 may lead to an inherent increase in the surface area of the partition, leading to an increased interaction with, along with increased stirring rate of the vibro-polish media. Thus, mobility of the vibro-polish media may be enhanced through use of a finer spacing or hole arrangement 76, or alternatively increasing the size of the horizontal members and/or vertical members 72, 74.
In use, vibro-polishing provides a rubbing and/or cutting action which allows vibro-polishing to produce an essentially smooth surface finish, bought about by what may be described as a substantial lapping action. Consequently, there is no tearing action or unequal forces which may lead to the or each component 50 bending or becoming distorted. As such, and due to the fact that the container 60 and component 50 move as a substantially combined unit, fragile or delicate components 50 are supported by the media immediately surrounding the component 50, so making vibro-polishing suitable for a wide range of delicate applications where improvement of surface finish is required.
In particular, the surface finish of the or each component 50 is known to be at least partly attributed to the frequency and amplitude of the machine. Frequencies of vibration of the arrangement shown in
In a ‘fixed’ vibro-polishing process, one or more components 50 may be masked, fixed within the fixture 30 and masking arrangement 32 and lowered into a shaped container 60 comprising a suitable polishing media, such that the media is vibrated relative to the components or vice versa. Such a stationary component 50 process has been found to provide significant cycle time reduction to achieve a given surface finish.
In a further ‘traditional free flow’ vibro-polishing process, the or each component 50 may be instead placed in a free flow vibro-polishing container 60 and vibro-polished in surrounding ‘free’ media, for example, to restore surface finish during manufacture or following repair. Accordingly, components 50 are free to move within the media according to the natural movement of the media during processing. Most typically, components 50 move together with the vibro-polishing process in a circular motion within the container 60. In a modified ‘fixed vane’ vibro-polishing method used in conjunction with a traditional free flow vibro-polishing container, the media is vibrated relative to the components or vice versa. In using the presently described method, components 50 may be held stationary within the vibro-polishing container 60, allowing media to run through the components in order to achieve a polishing effect in a similar manner to a drag polishing process.
Referring again to
Referring again to
It will be appreciated that, in use, the assembled fixture 30 may interact with the partition 66, the interaction of the assembled fixture 30 with the partition 66 having the effect of slowing down the movement of the assembled fixture 30 within the vibro-polishing container relative to the vibro-polishing media 78. Thus, the assembled fixture 30 may move within the vibro-polishing media 78 relative to the partition 66 or rotate freely relative to the partition 66 at a slower rate than the vibro-polishing media 78 flow with a reduced risk of components 50 interacting with, or contacting each other.
In accordance with the above, during interaction of the assembled fixture 30 with the partitioning arrangement 66, frictional contact forces acting on the fixture 30 as a result of being pressed against the partition 66 via relative movement of the vibro-polishing media 78 and the fixture 30 may provide a resistance on the movement of the assembled fixture 30. Without the assembled fixture 30 and masking arrangement 32 surrounding and/or containing the component 50, components 50 may get trapped in the partition 66 at a fixed position and/or angle, causing the vibro-polishing media 78 to act on only one surface of the component 50, and leading to the potential occurrence of a non-uniform surface finish.
In a further example, and as shown in
Referring again to
It will be understood that the disclosure is not limited to the examples above-described and various modifications and improvements can be made without departing from the concepts described herein. For example, an arrangement for vibro-polishing may only comprise a fixture and a container. The remaining features (such as the agitator and the one or more partitions) may be added by a further manufacturer or end user. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.
Number | Date | Country | Kind |
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1522635.0 | Dec 2015 | GB | national |
1618086.1 | Oct 2016 | GB | national |