FIELD OF THE INVENTION
The present invention relates to a universal device for measurement of rhomboid
angles of T-root blades of steam turbines to determine Co-parallelity of root
radius of the blades.
BACKGROUND OF THE INVENTION
Steam turbine blade is a very precise and critical component. Presently, there is
no mechanical device or technical method available to check the Co-parallelity of
root radius of T-Root blades. According to the prior art, the Co-parallelity of root-
radius of the blades is manually determined by using a height gauge, which
often fails to provide an accurate result. An accurate determination of Co-
parallelity is a very important requirement as the same highly influences final
assembly of the blades in the rotor and casing grooves, which inter alia
maintains the axiallity.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a universal device
for measurement of rhomboid angles of T-root blades of steam turbines to
determine Co-parallelity of root radius of the blades which eliminates the
disadvantages of the prior art.
Another object of the present invention is to propose a universal device for
measurement of rhomboid angles of T-root blades of steam turbines to
determine Co-parallelity of root radius of the blades, which is enabled to
accurately and quickly determine Co-parallelity of root-radius of T-root blades.
A still another object of the invention is to propose a universal device for
measurement of rhomboid angles of T-root blades of steam turbines to
determine Co-parallelity of root radius of the blades which allows to maintain
desired axiallity of the blades in the rotor.
A further object of the invention is to propse a universal device for measurement
of rhomboid angles of T-root blades of steam turbines to determine Co-parallelity
of root radius of the blades which makes possible a defect-less fitting of the
blades in the rotor assembly.
A still further object of the invention is to propose a universal device for
measurement of rhomboid angles of T-root blades of steam turbines to
determine Co-parallelity of root radius of the blades which improves efficiency of
steam turbines.
SUMMARY OF THE INVENTION
Accordingly, there is provided a universal device for measurement of rhomboid
angles of T-root blades of steam turbines to determine Co-parallelity of root
radius of the blades comprising mainly of:
a main block (1);
a first plate (2) having a through hole;
a second side plate (3) having a counter bore hole;
at least one hexagonal Socket head screw (4);
a wing nut (5);
a hexagonal head nut (6);
a first screw (7);
a second screw (8); and
at least one pin (9).
Accordingly, there is provided a universal device for measurement of rhomboid
angles of T-root blades of steam turbines to determine Co-parallelity of root
radius of the blades comprising :
a main block (1) having a second screw (8) including a hexagonal
nut (6), and accommodating the steam turbine blades;
a first and second side plates (2, 3) having respectively a
throughbore and a counterbore vertically disposed in respect of the
main block (1); and
at least three pins (9), each horizontally inserted through said
bores of the side plates (2, 3) at different heights, the first and the
third pins (9) being positioned by one each hex.soc head screw (4),
the second pin (9) being located by a wing nut (5) including a first
screw (7); wherein a first blade is placed on the main block (1) and
vertically oriented to locate at a rhomboid angle by tightening the
blade by the side plates (2,3), the wing nut (5), and the hexagonal
nut (6), and wherein the rhomboid angles are measured for each
of the blades to determine co-parallelity of root radius of the blades
meant for assembly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIGURE 1 shows a 2D model of the main block of the inventive device.
FIGURE 1 (a) shows a 2D model of a first side plate of the inventive device.
FIGURE 1 (b) shows a 2D model of a second side plate of the device.
FIGURE 2 shows the detailed assembly of the device of the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
PRESENT INVENTION
Figure 2 shows the detailed assembly of the device of the invention. According to
invention, the turbine blades are disposed on the main block (1). The blades are
tightened by the two side plates (2, 3) vertically with the help of wing nuts (5)
and the hexagonal nut (6) one each pin (9) is joining the side plates (2, 3) at top
and bottom by the hex.soc head screws (4). A third pin (9) is joining the side
plates (2, 3) at the middle by the wing nut (5) including the first screw (7). The
second screw (8) fastens the hex nut (6).
For measurement of co-parallelity of root radius of the blade, a first blade is
placed on the main block (1) and then positioned vertically making a rhomboid
angle of the blade at 45 degree. Then the side plates (2, 3) are tightened with
the help of the wing nut (5) and the hexagonal nut (6). After fixing the blades in
the device and positioning the rhomboid angle, a height gauge is used for
measurement.
WE CLAIM:
1. A universal device for measurement of rhomboid angles of T-root blades
of steam turbines to determine Co-parallelity of root radius of the blades
comprising:
- a main block (1) having a second screw (8) including a hexagonal nut (6),
and accommodating the steam turbine blades;
- a first and second side plates (2, 3) having respectively a throughbore and
a counterbore vertically disposed in respect of the main block (1); and
- at least three pins (9), each horizontally inserted through said bores of the
side plates (2, 3) at different heights, the first and the third pins (9) being
positioned by one each hex.soc head screw (4), the second pin (9) being
located by a wing nut (5) including a first screw (7); wherein a first blade
is placed on the main block (1) and vertically oriented to locate at a
rhomboid angle by tightening the blade by the side plates (2, 3), the wing
nut (5), and the hexagonal nut (6), and wherein the rhomboid angles are
measured for each of the blades to determine co-parallelity of root radius
of the blades meant for assembly.
2. A universal device for measurement of rhomboid angles of T-root blades
of steam turbines to determine co-parallelity of root radius of the blades
substantially as herein described and illustrated with reference to the
accompanying drawings.

ABSTRACT

The invention relates to a universal device for measurement of rhomboid angles
of T-root blades of steam turbines to determine Co-parallelity of root radius of
the blades comprising a main block (1) having a second screw (8) including
a hexagonal nut (6), and accommodating the steam turbine blades; a first and
second side plates (2, 3) having respectively a throughbore and a counterbore
vertically disposed in respect of the main block (1); and at least three pins
(9), each horizontally inserted through said bores of the side plates (2, 3) at
different heights, the first and the third pins (9) being positioned by one each
hex.soc head screw (4), the second pin (9) being located by a wing nut (5)
including a first screw (7); wherein a first blade is placed on the main block (1)
and vertically oriented to locate at a rhomboid angle by tightening the blade by
the side plates (2, 3), the wing nut (5), and the hexagonal nut (6), and wherein
the rhomboid angles are measured for each of the blades to determine co-
parallelity of root radius of the blades meant for assembly.