| Title of Invention | AN INTERMEDIATE SLEEVE RING TO ACHIEVE INTERCHANGEABILITY OF BEARINGS IN EXHAUST HOOD SUPPORTED BEARINGS OF A TURBO-GENERATOR |
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| Abstract | An intermediate sleeve ring (11) in exhaust hood (2) supported bearings (4) (Figs. 1 & 2) of a turbo-generator is made in two halves with the top half of the sleeve ring (11) being bolted to the exhaust hood (2). The ring (11) holds the bearing shell (4) of drive end on its outer periphery. The ring (11) sits on the inner periphery of the exhaust hood (2). The internal surface of the ring (11) is provided with a milled spherical surface. The outer periphery of the drive end bearing (4) is spherically milled matching inner contour of the ring (11). The external surface of the ring is made cylindrical to fit in a groove in the exhaust hood (2). |
| Full Text | FIELD OF INVENTION The present invention relates to an intermediate sleeve ring in exhaust hood supported bearings of a turbo-generator. More particularly, the invention relates to a sleeve ring housing the drive end bearing of the rotor to make bearings of both ends identical to achieve interchangeability. BACKGROUND OF THE INVENTION Turbo-generator is supported by a bearing at each end of the rotor to transmit load and vibrations to foundation. The bearings are either end-shield mounted or pedestal mounted, depending on the machine design chosen. The front or turbine end bearing is also called as drive end bearing and rear bearing as non-drive end bearing. The type of support and the bearing shell employed on both ends is normally identical, whether it is end shield mounted or pedestal mounted. When coupled to specific turbines, it is necessary to locate the generator front bearing in the turbine exhaust hood. This bearing shall hence be designed to match with the internal contours of exhaust hood. In view of this, the congruence between the generator front and rear bearing is lost and as per the prior art, the bearings are different from one another. Customers are required to order for two bearings separately for any future requirements. The present invention is to achieve congruence of bearings used on front end and rear end, front end matching with the exhaust hood internals at the same time. An intermediate sleeve ring is invented to achieve the above. The outer surface of the sleeve matches with the inner contour of exhaust hood and inner with the outer surface of the bearing shell. OBJECTS OF THE INVENTION It is therefore an object of the invention to propose an intermediate sleeve ring in exhaust hood of a rotor of a turbo-generator which reduces the customers spares requirement, eliminates increase in casting variety, reduces manufacturing cycle time in view of standardization, eliminates variety in other bearing accessories like bearing seals, jack oil flexible pipes, vibration monitoring instrumentation etc. SUMMARY OF THE INVENTION In order to provide identical bearing at drive end and non-drive end of a rotor of a turbo-generator, an intermediate sleeve ring (11) is invented and provided in the exhaust hood (2) of the rotor. The sleeve ring (11) has its outer dia matching with the internal contours of the exhaust hood (2) while the inner dia matching with the outer dia of the bearing shell (4). The inner periphery of the ring (11) is spherically milled to allow the bearing sphere to swivel during operation. The inner ring (11) is placed between the exhaust hood (2) and bearing shell (4). The present invention thus enables the use of identical bearings at drive or front end and non-drive or rear end of a rotor. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The invention can now be described in detail with the help of the figures of the accompanying drawings in which Figure 1 shows arrangement of generator rotor on bearing supports as per prior art. Figure 2 shows the generator rotor on bearing supports as per the invention. Figure 3 shows the details of intermediate sleeve ring. Figure 4 shows the seating arrangement of bearing shell inside the exhaust as per the present state of the art. Figure 5 shows the bearing assembly inside exhaust hood as per present invention. DETAILED DESCRIPTION OF THE INVENTION In Figure 2 the schematic diagram of a typical bearing assembly inside the turbine exhaust hood (2) is shown. The generator rotor (5) is supported at its front side by drive end bearing shell (4) and at rear side by non-drive end bearing shell (9). These bearing shells are in turn are supported by separate pedestals (8). In some of the designs, the generator drive end bearing is placed in the turbine exhaust hood (2). This arrangement makes the length of overall shaft train compact and keeps the operating speed away from the rotor critical speeds. The bearing shell (4) as per the prior art shown in Figure 1 is provided with a rectangular groove (13) to accommodate the intermediate ring (11). This arrangement requires use of a bearing on drive side different from the shell used on non-drive end. The assembly of rotor (5) as per the invention is shown in Figure 2. As per the invention, an intermediate sleeve ring (11) is devised that is sandwiched between exhaust hood (2) and the bearing shell (4). This makes it possible to use a bearing shell on drive end (4) that is identical to bearing shell employed on non-drive end (9). The design of the intermediate sleeve ring (11) is shown in Figure 3. As shown in Figure 5 the inner periphery of the ring (11) is spherical milled (12) to allow the bearing sphere to swivel during operation as per the rotor operational catenaries. The assemblies of bearing shell (4) as per the present state of the art and as per the present invention inside the exhaust hood (2) are shown in Figures 4 and 5. While the present state of the art as in Figure 4 envisages a stepped type of groove in the outer surface of bearing shell, for facilitating locating in the exhaust hood (2), the bearing shell (4) as per invention as shown in Figure 5 proposes a spherically milled outer contour. The shell (4) seats in a sleeve (11) located in the exhaust hood (2) and whose internal surface is milled spherical (12). The external surface of the sleeve (11) is made cylindrical that fits in a groove turned inside the exhaust hood (2). The ring is made in two halves. The top half of the sleeve ring (11) is bolted to the bottom- parting plane of the exhaust hood (2). The ring holds the bearing shell (4) on its outer periphery. Hence, the ring holds the drive-end bearing (4) which is identical to non- drive end bearing (9). The present trend in the bearing design is to have a spherical contour on the shell periphery that ensures continuous bearing alignment with the shaft catenaries in all regimes of operation. Hence, the non-drive end is designed with this spherical surface. The grooved bearing shell on one side that is on drive end and spherically milled outer periphery for the other side make the individual shell designs different. This puts the customer at a disadvantage in view of the increased variety of components and additional efforts and investment for spares procurement and storage. The invention will make the bearing shells same on both ends, hence, the disadvantages indicated above are eliminated. WE CLAIM 1. An intermediate sleeve ring to achieve interchangeability of bearings in exhaust hood supported bearings of a turbo generator comprising: an intermediate sleeve ring (11) located in turbine exhaust hood (2) and made in two halves; the top half of the sleeve ring (11) being bolted to the exhaust hood (2); the ring (11) holding the bearing shell (4) on its outer periphery; wherein the said ring sitting on the inner periphery of the exhaust hood (2); characterised in that the internal surface of the ring (11) is provided with a milled spherical surface (12) matching the contour of the spherically milled outer periphery of drive end bearing (4) when the external surface of the said ring is made cylindrical to fit in a groove (14) in the exhaust hood (2). 2. An intermediate sleeve ring in exhaust hood supported bearings of a turbo generator as claimed in claim 1, wherein the drive end bearing being held by the sleeve ring (11) is identical to non-drive end bearing (9). 3. An intermediate sleeve ring in exhaust hood supported bearings of a turbo generator as claimed in claim 1, wherein the spherical contour (12) of inner surface of ring (11) and outer periphery of the front drive end bearing (4) allows said bearing to swivel during operation. |
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00964-kol-2006-correspondence others.pdf
00964-kol-2006-description(complete).pdf
00964-kol-2006-general power of authority.pdf
964-kol-2006-amanded claims.pdf
964-KOL-2006-CORRESPONDENCE.pdf
964-kol-2006-correspondence1.1.pdf
964-kol-2006-description (complete).pdf
964-KOL-2006-EXAMINATION REPORT REPLY RECIEVED.pdf
964-kol-2006-examination report.pdf
964-kol-2006-granted-abstract.pdf
964-kol-2006-granted-claims.pdf
964-kol-2006-granted-description (complete).pdf
964-kol-2006-granted-drawings.pdf
964-KOL-2006-GRANTED-FORM 1.pdf
964-kol-2006-granted-form 2.pdf
964-kol-2006-granted-specification.pdf
964-kol-2006-reply to examination report.pdf
| Patent Number | 251054 | ||||||||
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| Indian Patent Application Number | 964/KOL/2006 | ||||||||
| PG Journal Number | 08/2012 | ||||||||
| Publication Date | 24-Feb-2012 | ||||||||
| Grant Date | 20-Feb-2012 | ||||||||
| Date of Filing | 25-Sep-2006 | ||||||||
| Name of Patentee | BHARAT HEAVY ELECTRICALS LIMITED | ||||||||
| Applicant Address | REGIONAL OPERATIONS DIVISION (ROD), PLOT NO: 9/1, DJBLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA | ||||||||
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| PCT International Classification Number | H02G 1/00 | ||||||||
| PCT International Application Number | N/A | ||||||||
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