FIELD OF INVENTION
The present invention relates to a device for turbogenerator stator endwinding
vibration monitoring. More particularly, the invention relates to a flanged device
for directly connecting a plurality of fibre-optic accelerometers (FOAs) to a
vibration monitoring system.
BACKGROUND OF INVENTION
Vibration monitoring of the stator endwinding by utilizing a vibration monitoring
system having an interfacing device, is known.
The existing systems for vibration monitoring of the stator endwinding in a
turbogenerator by adapting FOA based interfacing device is gaining ground
worldwide owing to ability of functioning on higher electric potential during
normal operation of the generator as well as high voltage testing on standstill
condition. The known FOA based system has a provision for only 6-FOAs.
Generally, 12-probe based endwinding vibration monitoring is followed
universally, where half of the probes are mounted on each end-Turbine end and
the Exciter end. Subsequently, the probe-mounting configuration was revised to
18 FOAs comprising 9-FOAs on each side- Turbine and Exciter sides. The
modified device of similar dimensions can now accommodate 9-FOAs. Two such
devices are required for vibration monitoring.

one disadvantage / limitation of the existing flanged devices is that it has a
provision for only 6-FOAs.
Another disadvantage of the prior art devices is that the flanged device is quite
heavy and handling is also cumbersome.
A still another disadvantage of the known devices is that the flanged device is
quite heavy and handling is also cumbersome.
A further disadvantage of the prior art devices is that the warrant that the
welding is to be done on the generator casing. This operation, especially in the
generator sets which are in-operation at remote sites, becomes quite
cumbersome, time-consuming and above all, requires lot of precautionary
measures. As the generator windings are insulated copper structures, a minute
foreign object such as steel chip trapped in overhang can create major
breakdown and/or accident during operation.
Thus the known devices for interfacing FOAs with the monitoring system are not
adequate for direct vibration monitoring. They are un-flexible and difficult to
handle.
OBJECT OF THE INVENTION
An object of the present invention is to propose an improved flanged device for

interfacing an external vibration monitoring system to fibre-optic accelerometers
disposed on endwindings of a turbo generator stator.
Another object of the invention is to propose an improved flanged device for
interfacing an external vibration monitoring system to fibre-optic accelerometers
disposed on endwindings of a turbo generator stator, which eliminates the
disadvantages of the prior art.
A further object of the invention is to propose an improved flanged device for
interfacing an external vibration monitoring system to fibre-optic accelerometers
disposed on endwindings of a turbo generator stator, which enables direct
connectively to a larger number of FOAs.
A still further object of the invention is to propose an improved flanged device
for interfacing an external vibration monitoring system to fibre-optic
accelerometers disposed on endwindings of a turbogenerator stator, which
allows in-situ mounting and is user -friendly.
SUMMARY OF THE INVENTION
Accordingly, there is provided a "flanged-device" capable of directly connecting a
FOA probe-cable system to a turbogenerator stator endwinding monitoring from
inside and outside of the generator casing.

The device comprising a conical steel hollow cylinder and a circular steel lid
having 9-holes. The device can be installed on the generator casing by means of
Allen bolts. It has rubber sealing O-ring at top and bottom to prevent the
peripheral hydrogen leakage. FOAs with integrated cables have inbuilt sealing
arrangement to prevent any leakage from their respective holes. These FOAs
mounted on the endwindings are then, routed through the hollow section of the
device one-by-one and bolted with the lid. The lid in-turn, is bolted to the hollow
conical cylinder. Outside connections to the monitoring system are made through
suitable connectors with integrated cables.
The device can be bolted to a turbogenerator casing from outside and no
welding is required for fixing it to the casing.
The device is compact and lighter and can be handled and fixed by even a single
person only.
The device prevents leakage of cooling medium of turbo generator.
The device is used for interfacing the output signal connectors of fibre-optic
accelerometers (FOAs) -mounted on endwindings of turbogenerator stator, to
outside vibration monitoring system. The device remains flanged and
fixed/bolted to the side of turbo generator casing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure - 1 shows a hollow circular flange of the flanged-device according to the
invention.
Figure - 2 shows a circular metallic lid connectable to the hollow cylinder flange
of figure - 1 to form the flanged-device of the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
As shown in figure - 1, the device consists of a hollow conical steel cylinder-(l)
which is made-up of hard tempered mild steel. It is centrally hollow to provide a
cable routing from inside the generator casing. The conical angle and slant
height is optimally selected in order to provide an allowable bending radius to
the fibre-optic cable. Provisions of 4-bind threaded holes (2) at outer top
periphery is used to fasten a circular metallic lid (5) while at the bottom, at least
8-holes (3) are drilled for bolting it on the side the generator casing. At least one
rubber O-ring (4) is provided to prevent peripheral leakage of the cooling
medium (hydrogen).
The hollow flange (1) is closed /covered by at least one circular metallic lid-(5).
The lid (5) is also made-up of mild steel. It has centrally 9-holes (6)

for taking out FOAs from inside the generator as shown in Fig-2. The lid (5) is
secured on the top periphery of the flange (1) by means of 4-Allen bolts (2). The
hollow conical steel cylinder-(l) and the circular metallic lid-(5), are releasably
fixed by means of at least 8-Allen bolts (4) on the side of the generator casing.
Overall dimension of the device has been optimally designed and the constituent
components are machined to a required finish. After complete assembly of the
device with 9-FOAs, the device can be installed on the generator casing. The
device after subjecting to air pressure of 8-bar for 48-hours, did not exhibit any
leakage of the cooling medium.

WE CLAIM
1. An improved flanged device for directly connecting a plurality of FOAs to
an external vibration monitoring system, the FOAs being mountable on
the endwindings of a turbogenerator stator, the device comprising:
- a metallic conical cylinder (1) providing routing of cables from
inside the generator casing, the conical angle including the slant
height of the cylinder so optimized as to allow limited bending
radius of the optical fibre cables, the cylinder (1) having at least
four blind holes (2) on the outer top periphery, and at least eight
holes (3) at the bottom for releasably attaching the device by
means of a first set of Allen bolts (4) on the side of the generator
casing ; and
- a metallic lid (5) having a plurality of holes (6) to allow egress of
the FOAs from inside the generator, and being releasably fixed on
the top periphery of the cylinder (1) via a second set of alien bolts
(2).

2. The device as claimed in claim 1, wherein the metallic cylinder (1) is
produced from hard tempered mild steel, and wherein the cylinder is
configured to have a centrally hollow section.
3. The device as claimed in claim 1, wherein the metallic lid (5) is of a
material corresponding to that of the metallic cylinder (1).

4. The device as claimed in claim 1, wherein the first set of alien bolts (2)
comprises four number of bolts.
5. The device as claimed in claim 1, wherein the second set of alien bolts (4)
comprises eight number of bolts.
6. The device as claimed in any one of the preceding claims, wherein the
metallic lid is having a circular shape.
7. The device as claimed in any of the preceding claims wherein, the plurality
of holes (6) on the metallic lid (5) comprises nine holes, and wherein the
plurality of FOAs corresponds to a number equivalent to the number of
holes (6).
8. The device as claimed in claim 1, comprising at least one groove (4)
arranged on the metallic lid (5) for sealing by using 'O' ring to prevent
leakage of the cooling medium.
9. An improved flanged device for directly connecting a plurality of FOAs to
an external vibration monitoring system as substantially described and
illustrated herein with reference to the accompanying drawings.

An Improved tlanged device tor directly connecting a plurality ot FOAs to an external vibration monitoring system, the FOAs being mountable on the endwindings of a turbogenerator stator, the device comprising; a metallic conical cylinder (l) providing routing ot cables from inside the generator casing, the conical angle including the slant height ot the cylinder so optimized as to allow limited bending radius ot the optical tibre cables, the cylinder (l) having at least tour blind holes (2) at the bottom for releasably attaching the device by means ot a tirst set of Allen bolts (4) on the side ot the generator casing; and a metallic lid (5) having a plurality ot holes (6) to allow
egress ot the FOAs from inside the generator, and being releasabiy fixed on the top periphery ot the cylinder (l) via a second set of alien bolts (2).