A Device for removing the Transport & Assembly (T&A) plate used for manufacturing of unwound core of 600 / 660 MW Turbo Generator.
1. FIELD OF THE INVENTION
The present invention relates to a device for removing Transport & Assembly (T&A) plate used for manufacturing of 600 / 660 MW Turbo Generator Core.
2. BACKGROUND OF THE INVENTION
Manufacturing is taken up for supply of Turbo Generator of various capacities ranging from 210 MW to 800 MW. The device has been made to suit the capacity of 600 / 660 MW Turbo Generator.
The Turbo Generator is a major product of Thermal Power Stations. The Turbo Generator consists of two main parts, of which one is Stator and the other is Rotor.
Stator has main components known as core, which is made up of laminated stampings of 0.5 mm thick. Length of the core 600 MW TG core is 6650 mm approximately and the weight of complete unwound core is around 190 to 200 tons.
The core is manufactured separately outside the stator frame and then the same needs to be lifted vertically for insertion into the stator body, all welding operation of the bushes for assembly with stator body to be completed after holding the core at particular position, and then dismantling the top lifting fixture and Transport and assembly plate (T&A) from the core body. Removing / transporting T&A plate from the stator location was always going to be a different proposition as the total weight of the T&A Plate is 10 tons. For this crane is being used. Maintaining location and position of the Transport and assembly plate (T&A) were performed with the help of packing's (temporary support) which is a very difficult operation taking considerable amount of time.
This was overcome with the help of developed device.

3. OBJECTIVE OF THE INVENTION
1. The objective of the present invention is to develop a device for removing of
transport and assembly plate which is used for the transport and insertion
of core into stator frame of 600 / 660 MW turbo generators.
2. Another object of the invention is to develop a device for removing of
transport and assembly plate that protects the lifting studs, nuts and (T&A)
plate.
4. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 : Process Map For 600 / 660 MW Stator Core Figure 2 : Sketch Of Core Lifting And Transportation Scheme Figure 3 : Shematic diagram of the developed device (A) Figure 4 : Bottom Ring (1)
Figure 5 : Bottom Support (2)
Figure 6 : Cross Beam (3)
Figure 7 : Pipe Support (4)
Figure 8 : Photographic view of the developed device (A)
Figure 9 : Assembly of core, assembly lifting fixture with core, tightening of T&A plate with nut & lifting fixture top.
Figure 10 : Core insertion into stator body.
Figure 11 : Core assembly lifting fixture.
5. SUMMARY OF THE INVENTION
Transport and assembly plate (T&A) is the base on which whole core assembly is carried out and this core is lifted through lifting fixture (Figure-9) where T&A plate act as the bottom support plate on which the complete core is transported and inserted into the stator frame (Figure-10). After the completion of welding of springs and spring basket (Figure-10), the

core and the stator frame becomes the single part and it is required to remove the lifting & transportation fixture and T&A plate etc. This fixture can be removed in vertical position only. After operation, to remove lifting fixture and T&A plate some packing is required which can be filled below the T&A plate to hold it in position.
The newly made device (Figure-3) having six cylinders with the provision of adjustable height, stiff enough to take the load of T&A plate which is approximately 10 tons. Three jacks are placed on three cylinders and packing on rest three. Lock nut is disassembled by lifting up T&A plate by hydraulic jacks. Then after removal of lifting hook & lifting fixture, the jacks are lowered to remove the T&A plate. OPERATION WISE STEPS FOR USE OF THE DEVICE
Step No 1:
After core assembly lifting fixture (Figure-11) is assembled to the core
(Figure-9), the fixture is tightened by nut through T&A plate (7) and lifting
fixture top (9). With the help of lifting fixture (9) top, core (10) is lifted and
transported into the stator body (11).
Step No 2: Core (10) is inserted in vertical position into the stator body
(11).
After assembly of core (10) with stator body (11) complete assembly is called unwound stator core (12). To carry out further operation we need to remove T&A plate (7). Now stator body (11) is still in vertical position, the distance from the ground level is 1800 mm and distance of T&A plate from ground level is approx. 3300 mm.
Step No 3: To remove T&A plate (7), insert packing below it at six locations (Approx. 3300 mm height).
Step No 4: Remove Nut from the top lifting fixture (9) and bottom of T&A plate (7).
Step No 5: Remove lifting fixture (9).

Step No 6: Hold T&A Plate (7) through slings and crane from inside the
core.
Step No 7: Remove all packing's and place T&A Plate at the ground level.
The present invention modifies step no. 3 and step no 7.
6. DETAILED DESCRIPTION OF THE INVENTION
a. Product description and its function:
Present invention is related to the Turbo Generator of 600 / 660 MW rating. Turbo Generator is made of the following major assemblies.
1. TGStator
2. TG Rotor
The invention made is used in the TG Stator Core. Core is one of the major components of Stator and is a part of Turbo - Generator, with main function as providing path to the rotating flux produced by the rotation of rotor in turbo generator. This core is attached to the stator body through the spring's, spring baskets & bushes. Core needs to be lifted and transported vertically for the insertion into the stator body. Bush is used to join the core with stator body after the completion of alignment of core with stator body. One end of bush is welded to the pads available on the spring basket and other end is welded to the spring available in the stator body. After completion of welding, the core is lifted up with T&A plate and is placed on the trunion support for removing T&A plate, Lifting fixture and lifting hook. Unwound core is ready at this stage. TG Stator is ready after completion of winding work. The process map of manufacturing of core is shown in Figure-1.
b. Present Practices and its constraints:
At present temporary support is placed below the T&A plate. Following constraints were noticed during the process: • Longer time required for assembly.

• More power consumption.
• More man power required to complete the job.
• Less safe to workman.
• Higher Fatigue.
c. Part details of the developed device:
1. Bottom Ring:
A ring is manufactured from 30 mm Thick plate of MS. This plate works as the base for the device.
2. Bottom Support:
Is a structure having six pipes of equal height welded on the bottom ring and top part is joined by a pipe.
3. Cross beam:
Cross beam is used to join two bottom studs diagonally so that under pressure structure does not fail. It is made by joining two flat long bars.
4. Pipe Support:
It is made up of Pipe at the top flat plate is welded and at the bottom a plate is welded having 4-holes at 90 degrees. This pipe is bolted to the bottom support.
5. Pipe:
Six pipes are joined at the top of bottom support to make it a structure.
6. Jack / Packing:
Jack / packing is placed on the top of the fixture during removal of T&A Plate.
d. Parts of the invention with reference numbers:
1. Device (A) -Figure-3
2. Bottom Ring (Item No-1) - Figure-3

3. Bottom Support (Item No-2) - Figure-3
4. Cross Beam (Item No-3) - Figure-3
5. Pipe Support (Item No-4) - Figure-3
6. Pipe (Item No-5) - Figure-3
7. Jack / Packing (Item No-6) - Figure-3

8. Transport and Assembly Plate (Item No-7) - Figure-10
9. Spring Basket (Item No-8) - Figure-10
10. Lifting Fixture Top (Item No-9) - Figure-9

11. Core (Item No-10)
12. Stator Body (Item No-11) - Figure-10
13. Unwound Core (Item No-12) - Figure-2, Figure-10
14. Core Assembly Lifting Fixture (Item No-B) - Figure-11 7. GAINS FROM THE INVENTION

• Faster disassembly of Fixture leading to reduction of manufacturing cycle time.
• Optimum utilization of manpower.
• Safe for task performers.
• Reduced fatigue 8B user friendly.
• Less power consumption.

We claim,
1 A device (A) for removing the Transport and Assembly plate (T&A) (07) used for manufacturing of unwound core of 600 / 660 MW turbo-generator designed in two heights comprising;
a bottom structure having a plurality of bottom support (2) welded on ring (1) at equal pitch circle diameter (PCD);
the other end of bottom support (2) joined with pipe (5), the bottom structure being reinforced by cross beam (3) to give rigidity;
a top structure comprising pipe support (4) joined at the top end of bottom
support (2) by nuts;
the top surface of pipe support (4) being flat wherein Jack (6)
and packings are filled between the top flat surface of pipe support (4) and bottom surface of Transport and Assembly plate (07) during operation.
2. A method of dismantling (T&A) plate (07) from the unwound core (12) comprising;
- assembling the core assembly lifting fixture (B) with core (10) and then tightening with (T&A) plate (7) and lifting fixture top (9) by nuts and bolts;
- transporting the complete assembly by holding into the hooks of lifting fixture top (9) with the help of a crane;
- attaching the core (10) with the stator body through the springs, spring baskets and bushes after completion of alignment of core with the stator where one end of the bush is welded to the pads available on the spring basket and the other end to the spring available in the stator body;
- lifting the core (10) with (T&A) plate (7) and placing on the trunion support for starting the dismantling operation of (T&A) plate (7), lifting fixture top (9) and lifting hook;
- bringing device (A) below the stator body (11) and core (12);

- filling the gap between cylinder (4) and (T&A) plate (7) with Jacks (6) at three places and by packing in rest three;
- lifting slightly the (T&A) plate (7) with the help of jacks (6) and removing the nuts for dismantling the (T&A) plate (07);
- removing the lifting hook and top lifting fixture (9) from the core;
- lowering the jacks (6) and removing the packing;

- hanging the (T&A) plate (7) from the sling and dismantling the pipe support (4) from the device (A);
- removing the bottom structure (2) of the device (A) from the underneath of stator (11);
- lowering the (T&A) plate (07) which was hanging from the slings to place at the base of core pit.