FIELD OF THE INVENTION
The present invention generally relates to a device to perform punching near
balancing masses used for balancing a turbine. More particularly, the invention
relates to a device to perform punching/caulking process around substantially
unapproachable grooves on a turbine accommodating weights balancing the
turbine.
BACKGROUND OF THE INVENTION
It is known that when the mass centre axis of a rotor of a machine is different to
its running centre axis, an unbalance exists in the rotor. Practically all newly
machined parts are non symmetrical due to blow holes formed during the casting
process including other teaching problems for example, uneven number and
position of bolt holes, parts fitted off-centre, and machined diameters eccentric
to the bearing locations.
An unbalanced rotor, when rotating, tends to revolve around its mass centre
axis. Because the bearings restricts this movement, the centrifugal force
generated due to the unbalance, causes the rotor to vibrate. This vibration
causes wear and tear to the bearings, produces unnecessary noise, and, in
extreme cases may lead to a disintegration of the rotor itself. It is therefore
necessary to reduce the unbalance to an acceptable limit.
According to the prior art, removal of material by drilling, milling etc from the
heavy portion on the component is normally used to correct the unbalance.
Alternatively the unbalance can be corrected by adding material to the "lighter"

side of the component either by bolting or welding the balancing weights to
reduce the unbalance.
Since, a turbine runs at a very high RPM for a prolonged period of time, these
balancing weights tend to shift from their position leading to an unbalance of the
turbine from its centre line. In order to restrict such movement of the balancing
weights, caulking (act of punching or striking a material's face or head so hard
that they are knocked out) is done near the edges of the weights so that the
knocked out material blocks the movement of the balancing weight. (Refer
Figure 2).
According to the prior art, the process of caulking is manually done through
hammering. However, in some of the turbines the center distance is very less
and hammering cannot be done in such a small space because the motion
required for hammering gets restricted. (Refer Figure 1). This situation is
overcome by the invention of the device to perform cauiking process where the
hammering cannot be done due to insufficient space.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a device to perform
punching/caulking process around substantially unapproachable grooves on a
turbine accommodating weights balancing the turbine.
Another object of the invention is to propose a device to perform
punching/caulking process around substantially unapproachable grooves on a
turbine accommodating weights balancing the turbine, which allows caulking of

the material near the edges of balancing weights to restrict the shifting tendency
of the weights.
A further object of the invention is to propose a method operate a device to
perform punching operation at the edges of the balancing weight groove on the
turbine so as to maintain the balancing weights at their defined positions.
A still further object of the invention is to propose a device and a method to
perform caulking operation more efficiently to maintain the balancing weights in
fixed positions.
SUMMARY OF THE INVENTION
Accordingly, there is provided a device to perform punching/caulking process
around substantially unapproachable grooves on a turbine accommodating
weights balancing the turbine, comprising a hammer with a point noise for
plastic deformation at the edge of the grooves provided on the turbine to mount
balancing weights, the hammer allowing a successful caulking operation; a
plurality of Plates with threaded holes to hold and support the hammer to make
a threaded joint, and a plurality of threaded Bolts which can move within said
plates to convert a rotary motion generated on the hammer to linear motion
through said threaded joint formed between the bolts and the plate.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - Steam Turbine with center distance

Figure 2 - Balancing weight and punching process
Figure 3 - Complete caulking device according to the invention
Figure 4 - Plates with threaded holes of developed device of the invention
Figure 5 - Threaded bolts of developed device of the invention.
Figure 6 - Device getting used for caulking operation
Figure 7 - Complete caulking device as per photographic views.
Figure 8 - Setting up of device for performing caulking as per photographic
views.
DETAIL DESCRIPTION OF THE INVENTION
The present invention, i.e., a device is required to perform a caulking operation
near balancing masses, which comprises :-
- a hammer (1) with a point noise for plastic deformation at the edge of the
grooves provided on the turbine to mount balancing weights, the hammer
allowing a successful caulking operation;
- a plurality of Plates (2) with threaded holes to hold and support the
hammer (1) to make a threaded joint, and
- a plurality of threaded Bolts which can move within said plates (2) to
convert a rotary motion generated on the hammer (1) to linear motion
through said threaded joint formed between the bolts (3) and the plate
(2).
According to the invention, the hammer (1) of the device is formed of a curved
body with an extended tail projecting out of a restricted area created on account

of the short center space of the turbine. Near the curve, the plates (2) with
threaded holes curving towards the hammer side, are welded on both size of the
hammer along the periphery. The threaded bolts (3) are joined to the plates (2)
by flexible joints such that the length of the bolt inside and outside of the plate
can be increased or decreased as per requirement. (Refer figure 3).
According to the invention, the caulking process is performed on a turbine having
very less center area (which does not allow natural hammering process), using
the device. The process comprising:-
- maintaining the height of the threaded bolt to prevent touching of the bolt
on the surface area near the center of the turbine;
- determining visually the position where caulking is to be performed and
placing the nose of the device firmly on said position;
- adjusting the height of the bolt such that when the noise of the hammer
touching said caulking position, the head of the bolt touches the center
surface of the turbine, thereby restricts the upward motion of the device;
- hammering with the pointed nose to generate a plastic deformation at the
edge of the balancing weight groove to perform an effective caulking; and
- visually checking for the intensity of caulking to evaluate the amount of
material to be removed.

It is important to note here that since the line of action of the force of
hammering will always be from the bottom side, the hammer tends to move
towards the turbine side, wherein the bolt would restrict that motion. And
touching the head again to the center surface of the turbine would ensure that
the hammer noise is at the point of punching.

WE CLAIM
1. A device to perform punching/caulking process around substantially
unapproachable grooves on a turbine accommodating weights balancing
the turbine, comprising:
- a hammer (1) with a point noise for plastic deformation at the edge of the
grooves provided on the turbine to mount balancing weights, the hammer
allowing a successful caulking operation;
- a plurality of Plates (2) with threaded holes to hold and support the
hammer (1) to make a threaded joint, and
- a plurality of threaded Bolts which can move within said plates (2) to
convert a rotary motion generated on the hammer (1) to linear motion
through said threaded joint formed between the bolts (3) and the plate
(2).
2. The device as claimed in claimed in claim 1, wherein the threaded bolts
are flexibly joined to the plates having threaded hole such that the length
of the bolt inside and outside the plate can be increased or decreased as
per requirement.
3. A method operate a device to perform punching operation at the edges
of the balancing weight groove on the turbine so as to maintain the
balancing weights at their defined positions, comprising the steps of:-
- maintaining the height of the threaded bolt to prevent touching of the bolt
on the surface area near the center of the turbine;

- determining visually the position where caulking is to be performed and
placing the nose of the device firmly on said position;
- adjusting the height of the bolt such that when the noise of the hammer
touching said caulking position, the head of the bolt touches the center
surface of the turbine, thereby restricts the upward motion of the device;
- hammering with the pointed nose to generate a plastic deformation at the
edge of the balancing weight groove to perform an effective caulking; and
- visually checking for the intensity of caulking to evaluate the amount of
material to be removed.

ABSTRACT

The invention relates to a device to perform punching/caulking process around
substantially unapproachable grooves on a turbine accommodating weights
balancing the turbine, comprising a hammer (1) with a point noise for plastic
deformation at the edge of the grooves provided on the turbine to mount
balancing weights, the hammer allowing a successful caulking operation; a
plurality of Plates (2) with threaded holes to hold and support the hammer (1) to
make a threaded joint, and a plurality of threaded Bolts which can move within
said plates (2) to convert a rotary motion generated on the hammer (1) to linear
motion through said threaded joint formed between the bolts (3) and the plate
(2).