FIELD OF INVENTION:

This invention relates to a novel transportation methodology of vertical synchronous motors for reduction of assembly and dismantling time during motor erection at site.
More particularly, this invention relates to a new methodology developed for shipment of motor in semi-assembled condition wherever erection of motor cannot be carried out in fully assembled condition at site due to crane capacity limitation. It relates to a new method which saves a lot of manpower and time required for dismantling and assembly of motor during erection at site.
BACK GROUND OF THE INVENTION:
In old or existing practice, vertical synchronous motors are assembled and tested at works and dispatched to site in fully assembled condition. This ensures that all machine parameters like air gap, bearing clearances etc are maintained as tested at our works. Motors in fully assembled condition are extremely easy to install. Such motors are designed and manufactured in integrated stator frame concept where the motor can be shipped in fully assembled condition.
However at some project sites, there are overhead crane capacity limitation as per the customer contractual requirement. In such cases, motors can be shipped in dismantled condition i.e. stator, rotor, bearings, brake, slipring assembly, top and bottom bracket bearing brackets and bearing components etc separately supplied. Motor re-assembly at site will require a lot of manpower and time. Also, it is

envisaged that there will be some assembly constraints and issues which will arise during assembly of machine at site. Achieving the same setting of air gap, bearing clearances and other critical components like brake, slipring is very difficult. Also, number of boxes or dispatchable units will be more resulting in increase in transportation cost.
In light of above constraints, a novel transportation methodology for shipment of large rating vertical motors developed for reduction of assembly and dismantling time at site during erection of motor.
OBJECTS OF THE INVENTION:
It is therefore an object of the invention to provide a novel transportation methodology for shipment of large rating vertical motors in semi-assembled condition wherein rotor with top bracket is shipped on a dummy frame and the components like stator and other depatchable units are sent separately keeping in view of the crane capacity limitation at site.
Another object of the invention is to provide a novel system for reduction of assembly and dismantling time at site that reduces the number of skilled manpower required for complete re-assembly of motor at site, as well as reducing supervision charges for supervision of motor assembly at site, to be incurred by motor manufacturer.
Another vital and important object of the invention is to provide a novel arrangement wherein motor technical parameters like air gap setting, bearing clearances and setting of other critical components and assemblies do not get disturbed w.r.t motor as tested and assembled at manufacturer works ensuring achieving same motor performance parameters, including bearing performance parameters during actual motor in operation at site w.r.t. the parameters of running of motor during testing at manufacturer works and its subsequent approval of test results by customer guaranteeing that motor performance parameters will not be affected due to the innovative transportation arrangement.

SUMMARY OF THE INVENTION:
There is provided a novel transportation methodology for shipment of large rating vertical motors in semi-assembled condition where only the rotor with top bracket is shipped specifically on a dummy frame. All the assemblies’ rotor, thrust and guide bearing mounted on top bracket, brake, slipring etc remain in their actual position. Stator along with coolers and bottom bearing bracket is shipped separately keeping in view the crane capacity limitation. The arrangement is suitable for large rating vertical motors whose total weight is high and beyond the capacity of crane available at site.
More specifically, to illustrate the principles of the invention, our main consideration is to transport the rotor assembly along with top bearing bracket, brake slipring mounted on a dummy transportation frame and shipped as 1st dispatchable unit. The top thrust and guide bearing is assembled on top bracket. Brake hub and drum, brake element, brake mounting stool slipring, slipring and brake enclosure assembly, bottom guide bush all are included in this unit. Bottom bearing bracket and bottom guide pads are not part of this unit. A dummy transportation bottom bracket is used to seal the annular gap between dummy frame and rotor at bottom or DE side.
Stator assembly along with baffle support DE & NDE, baffle assembly DE & NDE, CACW coolers with housing LHS & RHS, terminal boxes and lower bearing bracket is shipped separately as 2nd dispatchable unit. Bottom guide pads are not part of this unit. All other components of bottom bearing except guide pads are supplied in assembled condition. Numbering of Bottom Guide pads (8 nos.) with reference to Lower Guide bearing bracket is done to ensure that correct guide pads are assembled on the marked position to achieve the same bearing setting as done at manufacturer works. Also, dowelling of bottom bearing bracket done with stator frame ensures the final bearing setting as per original setting done at manufacturer works. Top of stator assembly is covered with a top cover. A cover is used to seal the lower bearing bracket from bottom side i.e. DE.
Bottom guide bearing pads are shipped as 3rd dispatchable unit.

In accordance with broad principles of the invention, the top bearing bracket has been designed with special consideration of shipment of rotor along with top bearing, brake, slipring mounted on top bracket in dummy frame. Rotor assembly mounted on top bearing bracket is assembled on dummy transportation frame with the help of top bracket fixing bolts before dispatch. During lowering down of rotor inside dummy frame, lifting lugs of top bracket is used. The lifting lugs of new top bearing bracket are specially designed for lifting complete rotor assembly with bearing, upper bracket, slipring assembly & brake and inserting of rotor mounted on top bracket into dummy frame.
Dummy frame is used only for transportation purpose. It is required till the time assembly of motor at site is completed during erection. Same dummy frame can be used for number of machines or projects in case of sequential dispatch of motors. The weight of dummy frame is optimized and is very less w.r.t. stator frame. Provisions for mounting space heater inside dummy frame is provided along with space heater terminal box. Bottom transportation bracket is assembled on dummy frame at the place of bottom bracket fixing with the help of 12 nos. M16 bolts. Bakelite disc is used for bottom sealing of rotor at guide bush location. The new arrangement of bottom transportation bracket along with bakelite disc provides sealing between dummy frame bottom and rotor assembly at drive end side.
During erection at site, top and bottom covers of stator assembly are removed. Top or NDE baffle assembly (8 segments) is removed from stator assembly. Stator assembly along with Bottom bearing bracket is ready for rotor insertion, Stator assembly is placed at the final position of previously levelled motor stool or foundation. The rotor assembly mounted on top bracket is de-threaded from dummy frame. Here, the rotor mounted on top bracket is lifted using four specially designed lifting hooks of top bracket. It is then inserted into the actual stator assembly already placed at the final position. During assembly of rotor along with top bracket on Stator, dowel position of Stator frame and top bracket are matched exactly. Dowel is inserted between top bracket and stator frame. It ensures the same bearing clearances and air gap setting during final assembly at site. Bottom guide pads are assembled in bottom bracket and bearing clearances set within specified limits. Bottom bearing is boxed up.

Top (NDE) Baffle assembly (8 segments) are fitted back on Baffle support (NDE) after rotor insertion into stator. For this, four chequered plates of top bearing bracket are opened. Eight segments of baffle assembly are inserted through four openings provided in top bearing bracket for four chequered plates. Chequered plates are fitted back on top bracket.
Bottom guide pads to be inserted in Bottom bearing bracket. All other components of bottom bearing except guide pads has already been supplied in assembled condition. Numbering of bottom guide pads (8 nos.) with reference to lower guide bearing bracket has been done to ensure that correct guide pads are assembled on the marked position to achieve the same bearing setting as done at manufacturer works. Also, dowelling of bottom bearing bracket done with stator frame will ensure the final bearing clearances and setting as per original bearing assembly done at our works.
BRIEF DESCRIPTION OF DRAWINGS:
Fig 1 : Prior art i.e. 3D model of fully assembled vertical synchronous motor ready for dispatch in old or existing practice.
Fig 2 : 3D model of Rotor assembly mounted on top bracket along with top thrust and guide bearing arrangement, brake slipring, brake mounting stool, slipring and brake enclosure assembly.
Fig 3 : 3D model of the inventive art of the new developed dummy transportation frame.
Fig 4 : Sketch of the inventive art of the new developed dummy transportation frame.
Fig 5 : Sketch of the inventive art of bottom transportation bracket.
Fig 6 : 3D model of Stator assembly with CACW coolers to be shipped as 2nd unit.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION:
Fig 1 : Shows prior art i.e. 3D model of fully assembled vertical synchronous motor ready for dispatch as per existing practice. This is the standard method employed for transportation of large rating vertical synchronous motors in fully assembled condition as a single unit (1). This method cannot be employed for projects wherein there is a limitation of crane capacity. If crane capacity, 40 Ton in present case, is less than the total motor weight i.e. 57 Ton, motor erection is not possible. An innovative methodology devised for transportation of motor in semi-assembled condition in such a way that minimum assembly and dismantling is required during motor erection at site.
Fig 2 : Shows 3D model of Rotor assembly (2) mounted on top bracket (3) along with top thrust and guide bearing arrangement (7), brake, slipring, brake mounting stool (5), slipring and brake enclosure assembly (6). Dowelling of Brake mounting stool (5) with top bracket (3) is done so that all the components mounted on brake mounting stool (5) remain in the same setting as assembled at manufacturer works. The top bracket (3) is designed with sufficient strength and rigidity using analysis software ANSYS such that its 4 nos. lifting lugs are suitable for lifting complete rotor assembly with bearing, upper bracket, slipring assembly and brake.
Fig 3 & Fig 4 : Shows 3D model and sketch of new developed dummy transportation frame. An optimized dummy frame is designed and developed for transportation keeping in view the structural rigidity, material cost and transportation weight. It is designed such that outer profile is same as motor stator frame. Top and bottom stands of dummy frame are having same cross-section as stator frame, but thickness is less. Wrapper plate thickness is also reduced. Fixing holes on top stand (10) of dummy frame is same and hence it is suitable for fixing existing bolts of top bracket (3). Dummy frame is a fabricated steel structure made of 32mm thick top stand (10) connected to 16mm thick middle stand (11) through a plurality of uniformly spaced, vertical stiffening ribs (13) welded between the stands (10) & (11). The middle stand (11) is further connected to 20mm thick stand (16) through ribs (17), Stand (16) is connected to 25mm thick bottom

flange (15) through vertical ribs (14) welded between them. Wrapper plate or cover (12) having thickness 3mm is welded from all eight sides starting from top stand (10) and goes upto stand (16). Top stand (10) is machined to 25mm thick and top bracket (3) fixing holes are drilled on top stand (10) uniformly spaced. Stand (16) is machined from bottom side and number of holes are drilled for fixing bottom transportation bracket (22). Lifting lugs of dummy frame (24) are not to be used for lifting complete rotor assembly on top bracket. The height of dummy frame is kept approximately same as motor stator frame and location of stand (16) us such that bottom dummy transportation bracket (22) can be fixed in place of actual bottom bearing bracket (in fig.1).
Fig 5 : Shows sketch of bottom transportation bracket. It is a fabricated structure made of 10mm thick top disc (18) welded to a 20mm thick cylinder (19). The other end of cylinder (19) is welded to 20mm bottom disc (20). Plurality of stiffening ribs (21) are welded between disc (18), cylinder (19) and disc (20). Number of holes are drilled on top disc (18) so that bottom transportation bracket can be fixed on dummy frame at the stand (16). Same set of holes are drilled on stand (16) of dummy frame. Four holes M20 in bottom transportation bracket cylinder (19), made equally spaced all round the periphery, are used for radially locking rotor guide bush with the help of M20 screws. Rubber gaskets are used in radial space between 4 nos. M20 screws and guide bush. Bakelite plate is used for bottom sealing of rotor at guide bush location.
Fig 6 : Shows 3D model of Stator assembly (1) with CACW coolers (4), terminal boxes (9), baffle support and baffle assembly (8), lower bearing bracket (without guide pads) dispatched as 2nd unit. It consists of stator core and winding assembly i.e. stator capsule assembled in stator frame. Stator assembly (1) is covered by a top cover and bottom bearing bracket is covered by a bottom cover to seal the motor stator from bottom. Following dowelling is done to ensure the same bearing clearances and air gap setting during final assembly at site:
a) Dowelling of bottom plate of top bearing bracket (2) with top stand of stator assembly (1).

b) Dowelling of bottom disc of brake mounting stool (5) with top plate of top bearing bracket (2).
c) Dowelling of bottom bearing bracket with stator frame.
ADVANTAGES
Novel transportation methodology for shipment of large vertical motors in semi-assembled condition using dummy frame to reduce assembly and dismantling time of motor during erection at site. The invention is employed for large rating vertical motors whose total weight is high and capacity of crane available at site is significantly lower than the motor weight. In such cases, this invention helps in shipment of motors in 3 semi-assembled units. Rotor on top bearing bracket assembled on a dummy frame is dispatched as 1st unit. Stator with CACW coolers and bottom earing bracket is dispatched as 2nd unit. Bottom guide bearing pads are dispatched as 3rd unit. This arrangement is helpful in reducing the assembly and dismantling time of motor during erection at site. Required of skilled manpower at site for motor assembly is reduced upto a large extent. It results in reduction of overhead expenses required for motor erection at site thereby enhancing productivity.
Shipment of motor in different units is done in such a way that no disturbance of air gap setting, bearing clearances and other components occurs at site w.r.t. as assembled and tested condition of motor at manufacturer works. It ensures achieving same motor performance parameters, including bearing performance parameters during actual motor in operation site w.r.t. the parameters of running of motor during testing at manufacturer works and its subsequent approval of test results by customer. Correctness of assembly features of rotating and stationary components is maintained.
The novel arrangement shall also result in ease of transportation. Chances of damage of components during shipment is eliminated. Number of packing boxes is reduced. Same dummy frame can be used for number of machines or projects in case of sequential dispatch of motors.

WE CLAIM

A novel transportation methodology for shipment of large rating vertical motor in semi-assembled condition on a dummy transportation frame comprising:
a top (10) and bottom (15) stand of fabricated steel structure;
the top stand (10) made of 32mm thick steel sheet are connected to 16mm thick middle stand (11) through a plurality of uniformly spaced, vertical stiffening ribs
(13) welded between the stands (10) and (11);
the said middle stand (11) is further connected to 20mm thick stand (16) through vertical ribs (17);
the stand (16) is connected to 25mm thick bottom flange (15) through vertical ribs
(14) welded between them;
wrapper plate or cover plate (12) of thickness 3mm is welded on all eight sides of the octagonal shape dummy frame covering the region from top stand (10) and goes upto stand (16);
the stand (16) for fixing of top plate (18) of the bottom transportation bracket (22) which is a fabricated steel structure made of 10mm thick top disc (18) welded to a 20mm thick cylinder (19), the other end of the cylinder (19) is welded to 20mm thick bottom disc (20), wherein the number of holes are drilled on the top disc (18) at the outer periphery so that the bottom transportation bracket (22) are fixed with the dummy frame assembly (24) at the stand (16) having same set of matching holes as on top disc (18) of bottom transportation bracket (22);
characterized in that the rotor sub-assembly (25) of figure 2 are placed inside the dummy frame assembly (24) wherein the top bracket (3) of rotor assembly are rested over the top stand (10) on their matching holes tightened by nuts and bolts to prevent any vibration in the upper portion of rotor assembly (25) wherein the vibration at the

lower portion of rotor (22) is prevented by locking radially the rotor guide bush radially by four M20 bolts fixed on the equally spaced periphery of cylinder wall (19) with rubber gasket placed in between the radial space of bolt end and guide bush of rotor shaft (2).