CLIAMS:We Claim:
1. An apparatus for clamping seal ring wherein the apparatus comprises:
• an outer annular element comprising a plurality of first clamps mounted thereto by a plurality of first bolts wherein the plurality of first bolts clamps the outer periphery of the seal ring to the outer annular element using the plurality of first clamps;
• an inner annular element placed inside the outer annular element such that the outer annular element and the inner annular element are concentric and coplanar, wherein the inner annular element comprises a plurality of second clamps mounted thereto by a plurality of second bolts wherein the plurality of second bolts clamps the inner periphery of the seal ring to the inner annular element using the plurality of second clamps; and
• a plurality of longitudinally extending elements, wherein the longitudinally extending elements joins the outer annular element and the inner annular element.
2. The apparatus according to claim 1, wherein the outer annular element comprises a plurality of first bolt holes.
3. The apparatus according to claim 1, wherein the outer annular element supports the outer periphery of the seal ring.
4. The apparatus according to claim 1, wherein the inner annular element can be a circular disc or a circular plate.
5. The apparatus according to claim 1, wherein the inner annular element comprises a plurality of second bolt holes.
6. The apparatus according to claim 1, wherein the inner annular element supports the inner periphery of the seal ring.
7. The apparatus according to claim 1, wherein the longitudinally extending elements is selected from the group consisting of rods, beams, ribs and plates.
8. The apparatus according to claim 1 further comprises a plurality of first liners butted between the plurality of first clamps and the outer annular element.
9. The apparatus according to claim 1 further comprises a plurality of second liners butted between the plurality of second clamps and the inner annular element.
10. The apparatus according to claim 9 and 10, wherein the plurality of first liners and the plurality of second liners can be of different dimensions.
11. An apparatus for clamping seal ring wherein the apparatus comprises:
• an outer annular element comprising a plurality of first clamps mounted thereto by a plurality of first bolts wherein the plurality of first bolts clamps the outer periphery of the seal ring to the outer annular element using the plurality of first clamps;
• an inner circular disc placed inside the outer annular element such that the outer annular element and the inner circular disc are concentric and coplanar, wherein the inner circular disc comprises a plurality of second clamps mounted thereto by a plurality of second bolts wherein the plurality of second bolts clamps the inner periphery of the seal ring to the inner circular disc using the plurality of second clamps;
• a plurality of longitudinally extending elements, wherein the longitudinally extending elements joins the outer annular element and the inner annular element;
• a plurality of first liners butted between the plurality of first clamps and the outer annular element; and
• a plurality of second liners butted between the plurality of second clamps and the inner circular disc.
12. The apparatus according to claim 11, wherein the outer annular element comprises a plurality of first bolt holes and the inner circular disc comprises a plurality of second bolt holes.
13. The apparatus according to claim 11, wherein the outer annular element supports the outer periphery of the seal ring and the inner circular disc supports the inner periphery of the seal ring.
14. The apparatus according to claim 11, wherein the longitudinally extending elements is selected from the group consisting of rods, beams, ribs and plates. ,TagSPECI:FIELD OF INVENTION
The invention relates to a multi-functional fixture for clamping a seal ring of a low pressure turbine.
BACKGROUND
A fixture is a work or job holding or support device used in the manufacturing industry. The Fixtures generally used to securely locate (position in a specific location or orientation) and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability.
The primary purpose of the fixture is to create a secure mounting point for a work piece, allowing for support during operation and increased accuracy, precision, reliability, and interchangeability in the finished parts. It also serves to reduce working time by allowing quick set-up, and by smoothing the transition from part to part.
Most fixtures have a solid component which is affixed to the floor or to the body of the machine and considered immovable relative to the motion of the machining bit, and one or more movable components known as clamps. These clamps allow work pieces to be easily placed or removed, and yet stay secure during operation.
The seal ring fixture for a low pressure turbine securely locates and supports the seal ring. The clamps of the fixture secure the flanges of the seal ring. In prior art, the inner and the outer flanges of the seal ring are clamped using L shaped clamps and tapered wedges for each clamp. The job i.e. seal ring further requires a turnover to perform necessary operations on the other side of the job. Additional L shaped clamps and taper wedges are required to support the job after turnover to prevent distortion and then balance welding is performed followed by stress relieving.
To turnover the job, clamps had to be disassembled before turning over the job and again clamps needed to be fixed after turning over of the job. This turning over of job consumes a lot of time and man power, thus reduces the productivity of the process. Further, distortion of the seal ring occurs when the clamps are cut during the process of turnover and after completion of welding. Hence the job has to undergo a process of straightening/pressing twice. Moreover additional fixture/loads are arranged for stress relieving.
Hence there is a need to devise a fixture which can overcome the above issues. The proposed design of fixture eases the turnover of the job hence reduces the time and man-power consumed in turning over process. Also during turning over, clamps are not removed hence this helps in controlling the distortion of seal ring as minimum as possible and re-leveling is also not required. Further, the requirement of the addition load is also eliminated during stress relieving.
SUMMARY
It is an object of the invention to provide an apparatus for clamping a seal ring of a low pressure turbine wherein the apparatus comprises an outer annular element comprising a plurality of first clamps mounted thereto by a plurality of first bolts wherein the plurality of first bolts clamps the outer periphery of the seal ring to the outer annular element using the plurality of first clamps; an inner annular element placed inside the outer annular element such that the outer annular element and the inner annular element are concentric and coplanar, wherein the inner annular element comprises a plurality of second clamps mounted thereto by a plurality of second bolts wherein the plurality of second bolts clamps the inner periphery of the seal ring to the inner annular element using the plurality of second clamps; and a plurality of longitudinally extending elements, wherein the longitudinally extending elements joins the outer annular element and the inner annular element.
It is another object of the invention to provide an apparatus in which the outer annular element supports the outer periphery of the seal ring and the inner annular element supports the inner periphery of the seal ring.
It is yet another object of the invention to provide an apparatus that works as a multi- functional fixture for the fabrication of the seal ring of a low pressure turbine and can be used from initial to the end phase of its fabrication i.e. initial set up for flanges of the seal ring to the stress reliving of the components.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which base flanges of the seal ring are clamped directly on the apparatus.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which no extra connection supports are required to clamp base flanges of the seal ring.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which turnover of the seal ring is done with seal ring clamped to the apparatus.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which re-leveling of the seal ring is not required.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which straitening activity is eliminated and also distortion is controlled to a minimum level.
It is yet another object of the invention to provide an apparatus for clamping a seal ring in which Stress reliving is done using same fixture and no additional fixtures are required. The same apparatus can be used throughout the process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the apparatus 1 of the invention;
FIG. 2 illustrates the top view of the apparatus 1;
FIG. 3 illustrates the perspective view of the apparatus 1 with the flanges 15, 16 of the seal ring 14 attached to it;
FIG. 4 is perspective view of the apparatus 1 with seal ring clamped to the apparatus 1 during stress reliving; and
FIG. 5 is perspective view of the apparatus 1 in the turnover position.
DETAILED DESCRIPTION
In the detailed description of the present invention, numerous specific details are described to provide a thorough understanding of the various embodiments of the present invention. However, a person skilled in the relevant art will recognize that an embodiment of the present invention can be practiced without one or more of the specific details, or with other apparatuses, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.
In executing the objects and purpose of the invention, there has been provided a seal ring apparatus 1. Fig.1 illustrates the top view of the apparatus 1 for clamping the seal ring (not shown). The apparatus 1 comprises an outer annular element 2 having an outer diameter D1, an inner diameter D2 and pitch circle diameter (PCD) P1, an inner annular element 3 of outer diameter d1, an inner diameter d2 and pitch circle diameter (PCD) P2 such that the outer diameter d1 of the inner annular element 3 is less than inner diameter D2 of the outer annular element 2 i.e. d1 < D2 as shown in FIG.1 and a plurality of longitudinally extending elements 4.
The outer annular element 2 comprises a plurality of first clamps 5 that ensure total contact between the outer annular element 2 and the seal ring mounted thereto by a plurality of first bolts 9 as shown in FIG.2. The plurality of first bolts 9 clamps the outer periphery of the seal ring to the outer annular element 2 using the plurality of first clamps 5. The outer annular element 2 further comprises a plurality of first bolt holes 11 along the pitch circle of PCD P1 for plurality of first bolts 9. The outer annular element 2 supports the outer periphery of the seal ring. The outer annular element 2 further comprises a plurality of first liners 7 butted between the plurality of first clamps 5 and the outer annular element 2 as shown in FIG. 3. The thickness of plurality of first liners 7 is same as the thickness of the seal ring flange to ensure total contact between the seal ring flange and the outer annular element 2.
The inner annular element 3 is placed inside the outer annular element 2 such that the outer annular element 2 and the inner annular element 3 are concentric and coplanar as shown in FIG. 2. Since inner diameter D2 of the outer annular element 2 is greater than the outer diameter d1 of the inner annular element 3 i.e. D2 > d1, there is a formation of gap G1 between the inner diameter D2 of outer annular element 2 and the outer diameter d1 of the inner annular element 3. The inner annular element 3 comprises a plurality of second clamps 6 that ensure total contact between the inner annular element 3 and the seal ring mounted thereto by a plurality of second bolts 10. The plurality of second bolts 10 clamps the inner periphery of the seal ring to the inner annular element 3 using the plurality of second clamps 6. The inner annular element 3 further comprises a plurality of second bolt holes 12 along the pitch circle of PCD P2 for plurality of second bolts 10. The inner annular element 3 supports the inner periphery of the seal ring. The inner annular element 3 further comprises a plurality of second liners 8 butted between the plurality of second clamps 6 and the inner annular element 3 as shown in FIG.3. The thickness of plurality of second liners 8 is same as the thickness of the seal ring flange to ensure total contact between the seal ring flange and the inner annular element 3.
In an embodiment of the invention, the plurality of first clamps 5 and the second clamps 6 can be independently selected from the group comprising of metallic strip, metallic leaf, metallic plate and metallic washer.
In an exemplary embodiment of the invention, the inner annular element 3 can be a circular disc or circular plate.
In another embodiment of the invention, the number and the dimensions of the first bolt holes 11 in the outer annular element 2 is different from the number and the dimensions of the second bolt holes 12 in inner annular element 3 respectively.
In yet another embodiment of the invention, the number and the dimensions of the first bolts 9 in the outer annular element 2 is different from the number and the dimensions of the second bolts 10 in the inner annular element 3 respectively.
In yet another embodiment of the invention, the number and the dimensions of the first clamps 5 in outer annular element 2 is different from the number and the dimensions of the second clamps 6 in the inner annular element 3 respectively.
The apparatus of the invention further comprises the plurality of longitudinally extending elements 4 as shown in FIG. 2. The longitudinally extending elements 4 join the outer annular element 2 and the inner annular element 3 in a same plane that provides the support to the outer annular element 2 and the inner annular element 3. The elements 4 also act as stiffeners.
In an exemplary embodiment of the invention, the plurality of longitudinally extending elements 4 can be rods, beams, ribs and plates.
In another embodiment of the invention, the plurality of first liners 7 and the second liners 8 can be independently selected from the group comprising of metallic strip, metallic leaf, metallic plate and metallic washer.
In yet another embodiment of the invention, the seal ring 14 is assembled and fabricated by clamping it to the apparatus 1 of the invention. The seal ring 14 comprises an outer base flange 15 and an inner base flange16. FIG. 3 illustrates the perspective view of the apparatus 1 with the flanges 15, 16 of the seal ring 14 attached to it. The flanges 15, 16 are clamped directly on the apparatus 1 whereas no extra connection supports are required. The outer base flange 15 is clamped to the outer annular element 2 with the help of plurality of first clamps 5, plurality of first liners 7 and plurality of first bolts 9 and the inner base flange 16 is clamped to the inner annular element 3 with to the help of plurality of second clamps 6, plurality of second liners 8 and plurality of second bolts 10 as shown in FIG. 3.
FIG. 4 is perspective view of the apparatus 1 with seal ring 14 clamped to the apparatus 1 during stress reliving. A first SS plate 17 is fitted and welded to the outer base flange 15 as shown in FIG. 4. Further, a second SS plate 18 is fitted and welded on the inner base flange 16 and a third SS plate 19 is welded to the first SS plate 17 and the second SS plate 18. Then weld visual and non-destructive testing (NDT) is performed for any defects during the welding process.
The apparatus 1 can be turned over as shown in FIG. 5 to complete the processes on the other side of the seal ring 14. Thus, there is no need to disassemble the clamps 5 and the clamps 6 to do the work on the bottom side of the seal ring 14. After turnover, the third SS plate 19 is welded to the first SS plate 17 and the second SS plate 18 from the gap G1 formed between the outer annular element 2 and the inner annular element 3 of the apparatus 1 as shown in FIG. 5. The turnover of the apparatus 1 is quite advantageous since no unclamping of the seal ring 14 is done that eliminates the re-leveling of the seal ring 14 and straitening activity that is generally required during the fabrication of the seal ring 14. Moreover distortion is controlled to a minimum level. The same apparatus 1 can be used repeatedly and throughout the process. Thus non-value added activity/fatigue time is reduced and the productivity is enhanced. Then weld visual and non-destructive testing (NDT) is performed for any defects during the welding process.
Further, no additional fixture is required to do the stress reliving of the seal ring 14 as it can done in the position as shown in FIG. 4. The apparatus 1 is also used as load during stress reliving process hence load used during stress reliving is eliminated. Then weld visual and non-destructive testing (NDT) is performed for any defects during the welding process and after dimensional check of the seal ring, it is sent to machining.
The apparatus 1 of the present invention is a multi- functional fixture designed and developed for the fabrication of the seal ring 14 of a low pressure turbine which can be used from initial to the end phase of its fabrication i.e. initial set up for flanges of the seal ring 14 to stress reliving of the components. The purpose of this fixture is to minimize the distortion, enhance the production cycle time and reduction of support and stiffeners.
Further, the multi- functional fixture of the invention eliminates the repetitive use of L shaped supports and wedges to clamp the seal ring 14. Re-leveling of the seal ring 14 is not required and distortion is controlled to minimum throughout the process. Sub-assembly of Base Flange can be done without extra stiffeners and time taken for gas-cutting of supports is eliminated. Load used in Stress Relieving and Straitening activity is eliminated in the fabrication process. Same fixture can be used repeatedly and throughout the process thus non-value added activity/fatigue time is reduced.
It is noted that the foregoing has outlined some of the more pertinent objects and embodiments of the present invention. This invention may be used for many applications. Thus, although the description is made for particular arrangements and methods, the intent and concept of the invention is suitable and applicable to other arrangements and applications. It will be clear to those skilled in the art that modifications to the disclosed embodiments can be effected without departing from the spirit and scope of the invention. The described embodiments ought to be construed to be merely illustrative of some of the more prominent features and applications of the invention. Other beneficial results can be realized by applying the disclosed invention in a different manner or modifying the invention in ways known to those familiar with the art.