FIELD OF INVENTION
The present invention relates to a single piece regulating ring adaptable to Hydro
Turbine with external regulation of guide apparatus. More particularly the present
invention relates to a reduced size single piece regulating ring development on
application of an ingenious method of inserting the regulating ring into turbine pit as
a single piece eliminating splitting into halves for the purpose of erection.
BACKGROUND OF THE INVENTION
In a hydroelectric power station having Francis type turbine, regulating ring is a
major item of guide apparatus and has the following function. It connects the
governor controlled servomotor (hydraulic cylinder) to the Guide Vanes located
around the runner. The guide vane servomotor is connected to regulating ring to
guide vanes. Regulation of Turbine is done by turning all the guide vanes in
synchronism through the regulating ring.

Depending upon the size of turbine two types of regulations are used
for the turning mechanism.
In Internal Regulation type the regulating ring is located on the inner
side of guide vane pitch circle diameter. This is used in big turbines
where there is ample space for access to shaft seal of turbine.
In External Regulation type, the regulating ring is located on the
outer side of guide vane pitch circle diameter. This type of regulating
is used in smaller turbines where there is not enough space available
for approach to shaft seal of turbine.
In such turbines, the outer diameter of regulating ring becomes so
big, that it cannot be lowered through the bore in the concrete
portion, supporting generator bottom bearing. Hence for the
purpose of lowering, the regulating ring through this concrete core,
the regulating ring is split into halves. The haves of regulating ring
are lowered vertically into the turbine pit. The halves are turned to
their natural horizontal position inside the turbine pit and assembled.
Thus only for the sake of erection, namely lowering of regulating ring
into turbine pit, the relating ring is split into halves.

In order to provide a joint, which is as strong and rigid as the single
integral regulating ring; a number of fitted bolts of quite a big size
are to be provided. To accommodate those bolts the height of
regulating ring has to be increased. Increased height increases
twisting moment which in turn demands more inertia. Thus splitting
the regulating ring increases weight (material cost), machining cost
and the total manufacturing cycle.
PRIOR ART
In this design regulating ring is made in halves with a bolted joint.
The halves are lowered through the restricted concrete bore below
generator bearing and bolted inside the turbine pit.
Regulating ring of this design is bulky, heavy, costly, less rigid, and
has a longer fabrication and machining cycle.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a
compact (reduced size) single piece regulating ring development
adaptable to hydro-turbine with external regulation of guide
apparatus which eliminates the disadvantages of prior art.

Another object of the present invention is to propose a compact
(reduced size) single piece regulating ring development adaptable to
hydro-turbine with external regulation of guide apparatus which
eliminates the bolted joints of regulating ring halves and there by
improving rigidity.
A still another object of the present invention is to propose a compact
(reduced size) single piece regulating ring development adaptable to
hydro-turbine with external regulation of guide apparatus which
reduces the height of regulating ring, thus in turn reducing twisting
moment.
A further object of the present invention is to propose a compact
(reduced size) single piece regulating ring development adaptable to
hydro-turbine with external regulation of guide apparatus which
provides easier approach space to turbine shaft seal other parts due
to reduction of height of regulating ring.
A still further object of the present invention is to propose a compact
(reduced size) single piece regulating ring development adaptable to
hydro-turbine with external regulation of guide apparatus which
eliminates 4 joint flanges, reduces the material cost, fabrication cost
and reduce process cycle by about 40%.

A yet further object of the present invention is to propose a compact
(reduced size) singie piece regulating ring development adaptable to
hydro-turbine with external regulating of guide apparatus which
discards the material and machining cost of joining bolts and dowels
and machining cost.
SUMMARY OF THE INVENTION
In the present invention the regulating ring of a hydro Turbine with
external regulation of guide apparatus is made as a single piece and
very compact in size. The single piece regulating ring in then
ingeniously lowered into the turbine pit by providing two diametrically
opposite slots between the sole plates of generator bearing support.
These slots are subsequently covered by tow plates. With innovative
changes in the support arrangement for regulating ring, the
mounting arrangement of servomotor and provision of lower slots in
the concrete support below generator, the joints of regulating ring
are eliminated thereby making it rugged and economical.

BRIEF PESCRIPTION OF THE ACCOMPANYING DRAWING
Fig-1 Conventional design of guide apparatus with bolted joint
Regulating Ring (prior art).
Fig-2 The new compact design of regulating ring without joints.
Fig-3 Mounting arrangement of Guide Vane Servomotors, as per prio
art.
Fig-3 A mounting arrangement of guide vane servomotor as per new
invention.
Fig-4 Scheme of lowering the halves of regulating ring of previous
design (prior art).
Fig-5 View showing the new compact regulating ring being lowered
through slot. (Stage-1 of erection).
Fig-6 View showing the new compact regulating ring being tilted
within turbine pit (Stage-2 of erection).
Fig-7 View showing the new compact regulating ring being lowered
on stay ring (Stage-3 of erection).

In the new development of servomotor bigger mounting bolts as
shown in fig 3 are only located on the two sides of the servomotor
with no bolts o the bottom or top. Thus since tightening space below
servomotor is not required, the servomotors mounting elevation Is
lowered there by reducing the height of regulating ring. Reduction in
height of regulating ring reduces the twisting moment and hence the
inertia requirement for the same and hence less slot width required
for lowering of regulating ring into the turbine pit.
In the conventional design shown in fig-1 the rotary oscillating
motion of regulating ring is guided on a cylinder mounted on the
outer diameter of stay ring. This outer guide ring/guide cylinder is
eliminated by taking the guide on the top cover outer diameter as
shown in fig-2. In the conventional design the uplift of regulating
ring during it's motion is arrested by a retaining ring separately
bolted on stay ring.
In the innovated design, the bolting of retaining ring is clubbed with
that of top cover to stay ring bolting, thus giving lot of space for
regulating ring to be moved radially inwards. Thus by eliminating the
extra guide cylinder of regulating ring and clubbing bolting of
retaining ring with top cover the outer dia of regulating ring is
drastically reduced.

For lowering of the modified compact and slim regulating ring into the turbine pit an
ingenious method has been devised. The concrete slab supporting the generator
bottom guide bearing was studied for unused space. The generator bottom guide
bearing has four arms resting bolted to the four sole plates. The space between
generator sole plates can be used for lowering the regulating ring.
Two diametrically opposite slots whose width is slightly larger than the height of
regulating ring have been provided (see 5, 6, 77). The depth of slot from the
concrete bore is such that the distance between the ends of diametrically opposite
slots is bigger than the outer diameter of regulating ring.
The regulating ring is then lowered vertically through the slots with the height of
regulating ring passing through the slot width. After the regulating ring clears the
slot, it is then turned to its natural horizontal position. The slots in concrete slots
below generator bearing are then closed by plates for generator pit air sealing
purpose.
The regulating ring is a 'O' shaped ring or a circular ring with predetermined
diameter. This ring is slidable between the two diametrically opposite slot vertically
disposed. Such 'O' shaped ring called circular ring after clearing the slot is then
turned to its horizontal position for mounting the assembly and such circular ring is
fastened from diametrically opposite sides. The circular ring is made of steel
material.

KEY FEATURS
Reference; Feature Figure
character
1 Regulating ring of prior art. 1
2 Joint change in prior art. 1
3 Stay ring in prior art. 1
4 Retaining ring bolting as per 1
prior art.
5 Servomotor location W.R.T. stay 1
ring in prior art.
6 Guide in prior art. 1
7 G.V.axis in prior art. 1
Maximum outer DIA bigger that
8 generator bore hence split into 1
two for erection in prior art.
9 New compact light weight 2
regulating ring.
10 Servomotor location lowered. 2
11 Stay ring as per new invention. 2
12 Retaining ring bolting clubbed 2
with top cover.
13 Guide shifted from stay ring to 2
top cover O-D.

Reference: Feature Figure
Character
14 G.V.axis as per new invention 2
15 Max outer DIA smaller than 2
generator bore, hence single piece
16 Servo cylinder in prior art 3
17 Mounting bolts in prior art 3
Space required for lightening of
18 bottom bolts below cylinder in prior 3
art
19 Bottom of pit liner in prior art 3
Servomotor location high due to
20 tightening space for bottom 3
mounting bolts in prior art
21 Mounting bolts on two sides as per 3A
invention
22 Servomotor cylinder as per 3A
23 Bottom of pit liner as per invention 3A
Servomotor location lowered due to
24 tightening of mounting bottom 3A
sides
25 Regulating ring in halves 4
26 Generator barrel in prior art 4
27 Turbine pit in prior art 4

Reference: Feature Figure
Character
Regulating ring
28 halves assembled in 4
prior art
29 Generator sole plates 6, 7
30 Lowering slots 6,7
31 Concrete slab below 7
generator

WE CLAIM

1. A compact single piece / jointless regulating ring (9) for francis type
hydroturbines with external regulation of guide apparatus comprising:
- circular ring with reduced diameter
Characterized in that,
the ring (9) is a single piece (15) when outer diameter of the ring insertable
between the two diametrically opposite slot vertically disposed in the turbine
pit and is of reduced height for allowing less slot width for lowering the
regulating ring (9) and the regulating ring (9) is made of drastically reduced
outer diameter on account of clubbing of bolting of retainer ring with top
cover (12) that eliminates the extra guide cylinder of regulating ring.
2. The regulating ring (9) as claimed in claim 1 wherein, the ring is made of
steel material.
3. The regulating ring (9), as claimed in claim 1, wherein the said ring has
guide on outer diameter of top cover.

ABSTRACT

A COMPACT SINGLE PIECE / JOINTLESS REGULATING RING FOR FRANCIS
TYPE HYDROTURBINE WITH EXTERNAL REGULATION OF GUIDE
APPARATUS

The ring is a single piece (15) when outer diameter of the ring (9) slidable between the two
diametrically opposite slot vertically disposed in the turbine pit and is of reduced

height for allowing less slot width for lowering the regulating ring (9) and the regulating

ring is made of drastically reduced outer diameter for allowing clubbing of bolting of
retainer ring with top cover (12) that eliminates the extra guide cylinder of regulating

ring (9) .