FIELD OF THE INVENTION
The present invention relates to an improved fixing device for installation of air
cooler on the stator of hydrogenerator without compromising performance of the
air cooler.
BACKGROUND OF THE INVENTION
It is known in the art that air coolers are fixed to the stator frame for dissipating
the heat losses in the generator stator.
The prior art fixing devices of air cooler which is shown in figure 1(A) consists of
duct structure (3) welded on each face of the stator frame (2) for air cooler (1).
Lifting lug (6) is provided on the Air cooler (1) for holding the air cooler (1)
during mounting on the stator frame (2). Screws (4) and washers (5) at all sides
of the air cooler (1) are used for fixing of the air cooler (1) on the stator frame
(2). The fixing device of Air cooler of prior art are also shown in figure 1(B) &
1(C).
The prior art device has the following disadvantages :
1. Additional duct (3) on each cooler face of the stator frame (2) and a number
of screws (4) and washers (5) increases the cost of the device.
2. During mounting operation, the air cooler (1) is held through the lifting lugs
(6) which is welded on the air cooler (1) is time consuming and unsafe.
3. Number of holes are provided over all side faces of the air cooler (1) and the
stator frame (2) which create mismatching problem leading to increase in
process cycle time.

OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose an improved fixing device for
installation of air cooler on the stator of hydrogenerator without compromising
performance of the air cooler.
Another object of the invention is to propose an improved fixing device for
installation of air cooler on the stator of hydrogenerator without compromising
performance of the air cooler, which eliminates the requirement of additional
ducts and fastening members and reduces the cost of the device.
A further object of the invention is to propose an improved fixing device for
installation of air cooler on the stator of hydrogenerator without compromising
performance of the air cooler, which reduces the process time and makes the
installation process safe and easy.
SUMMARY OF THE INVENTION
Accordingly, there is provided an improved device for installation of air cooler on
the stator of hydrogenerator, the hydrogenerator having a plurality of air coolers
which are fixed to the stator frame (2) for dissipating the heat losses in the
generator stator, the device comprising : a plurality of cooler support blocks (7)
are welded at equal intervals to the stator frame for resting of air cooler(l)

a plurality of clamp block assy. (3) are fixed at the top of the cooler shall be
decided according to length for holding the air cooler (1) and a plurality of
fastening means screw and washers (4,5) to detachably attach the air cooler (1)
and the stator (2).
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention can be described in detail with the help of the figures in
accompanying drawings.
Figure 1(A) Fixing of air cooler of hydrogenerator in prior art
Figure 1(B) Showing section AA of air cooler fixing arrangement in prior art.
Figure 1(C) Showing view as arrow -D of air cooler fixing arrangement in prior
art.
Figure 2(A) Improved mounting device of air cooler on stator of hydrogenerator,
according to the invention.
Figure 2(B) Showing view as arrow-X & view as arrow-Y of the improved fixing
device of figure 2(A).
Figure 2(C) Showing section AA of the improved device of figure 2(A).
Figure 2(D) Showing section BB of the improved device of figure 2(A).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
In prior art, additional duct structure (3) is welded on each face of the stator
frame (2) for an air cooler (1) which increases cost. Air cooler (1) is held through
lifting lugs (6) during mounting on stator frame (2). After installation, a plurality
of screws and washers are fastened at all sides of air cooler (1) after matching
the holes of the stator frame (2) and the air cooler (1). This arrangement is
ensured for all the coolers which creates mismatching of holes during mounting
of the Air cooler (1). The details are shown in figures 1(A), 1(B) & 1(C).
The improved fixing device of the invented air cooler with stator frame is shown
in figures 2(A), 2(B), 2(C) & 2(D). A cooler support block (7) is fixed with the
stator frame (2) by fillet welding. A number of blocks (7) is fixed at equal
intervals at the bottom side of the air cooler (1). The air cooler (1) is rested on
these blocks. These support blocks (7) are welded to the stator frame (2) at the
time of trail assembly of Air cooler at works which eliminates the difficulties faced
due to mismatching of holes in the cooler flange and the stator frame and
therefore reduces the final assembly time. After that, a clamp block assy. (3) is
fixed at the top of the cooler (1). The number of clamp block assy (3) is decided
for each cooler depending upon its length. Finally, a plurality of screw (4) is
tightened with spring washer (5). The cooler support block (7) is welded to
stator frame (2) after setting the air cooler (1) in position, which ensures that
the coolers are tightly assembled. If required, two layers of wool felt (6) are
disposed in between.

The improved fixing device provides the following advantages :
1. Reduces the operation time due to proper clamping arrangement (cooler
support blocks (7) act as a safe arrangement instead of prior art process
of lifting of cooler through lifting lug.
2. Number of screws (4) and washers (5) including additional duct for each
cooler face are eliminated which decreases the cost.
3. The improved fixing device is also easy and safe to operate and reduces
mounting cycle time.

WE CLAIM :
1. An improved fixing device for installation of air cooler on the stator of
hydrogenerator, the hydrogenerator having a plurality of air coolers which
are fixed to the stator frame (2) for dissipating the heat losses in the
generator stator, the device comprising : a plurality of cooler support
blocks (7) welded at equal intervals to the stator frame for resting of air
cooler (1) a plurality of clamp block assy.(3) fixed at the top of the cooler
shall be decided according to length for holding the air cooler (1) and a
plurality of fastening means screw and washers (4,5) to detachably attach
the air cooler (1) and the stator (2) and, if required, with two layers of
wool felt (6) disposed in between.
2. The fixing device as claimed in claim 1, comprising multiple layers of
packing material, wool felt (6) interposed between the cooler and the
stator as required.
3. The fixing device as claimed in claim 1, wherein the fastening means
comprises screw (4) and washer (5) which tighten the air cooler (1) with
stator (2).
4. The fixing device as claimed in claim 1, wherein the number of clamp
block (3) is decided based on length of the coolers (1) to hold the air
cooler (1) from top side.

5. The fixing device as claimed in claim 1, wherein cooler support block (7) is
fixed at equal intervals at bottom side of the air cooler (1).

ABSTRACT

The invention relates to an improved fixing device for installation of air cooler on
the stator of hydrogenerator, the hydrogenerator having a plurality of air coolers
which are fixed to the stator frame(2) for dissipating the heat losses in the
generator stator, the device comprising : a plurality of cooler support blocks (7)
are welded at equal intervals to the stator frame for resting of air cooler(l); a
plurality of clamp block assy.(3) are fixed at the top of the cooler shall be
decided according to length for holding the air cooler(l) and a plurality of
fastening means screw and washers (4,5) to detachably attach the air cooler (1)
and the stator (2).