Title of the Invention
High speed Shaft support and alignment fixture
2 Field of the Invention
The present invention'relates to manufacturing, repair, overhaul of Gas
Turbines. Fixture is for supp on of high speed shaft after assembly.
3 Background of the invention
Gas Turbines are used in Marine application to get the advantage of high power
density with low foot print and weight. Gas Turbine assembly requires
critical control of clearances between rotating and stationary parts. One of
such component] Assembly Gas Turbine wh_ere maintaining correct
concentrically is of prime importance is High speed coupling shaft during
coupling of shaft flange with reduction gearbox flange. This shaft is used for
transferring gas turbine power to reduction gear box which in turn drives the
propeller/connected load. When Gas Turbine module is not mounted inside
the ship the rear end of the shaft is not connected to input flange of the
reduction gear box and remains overhung. This overhung causes distortion
of flange of coupling between GT and shaft Hence, shaft needs to be
supposed at overhung end in order to maintain sh‘aft center line.
3.1- Prior Art
Shaft earlier used to be supported from ground using wooden blocks which
.restrict movement of the module. Shaft was also suppofied using belt and
crane this arrangement also engages the crane full time and restricts
mpvement of module during storage. Under these circumstances there was
need of the device which allows free movement of enclosure without
disturbing shaft center line.
4 Brief Summary of the Invention
Gas turbine module is a box like structure which houses gas turbine and
high speed coupling shaft.‘ Rear end of coupling shaft is overhung with rear
flange outside the module.»There was need for supporting the rear end of the
shaft such that center line of the shaft with engine is not disturbed during
storage and handling of GT module. In the present fixture this need of
supporting of shaft and centralizing is achieved without using crane or ground
support.
5 Nylon roller on the top end of the fixture supports the end flange of the shift
during storage period of GT with Shaft. Nylon wheel support also facilitates
rotation of the shaft when required. The tool also facilitates up and down
movement of the shaft which helps in easy alignment with reduction gear box
input shaft flange correct concentrically.
10 Following are the advantages of the present fixture.
1. It supports rear end of the high speed shaft of GT when GT module is in
storage prior to coupling with reduction gear box. This support facilitates
manual rotation of the shaft as and when required. There is no need of
crane/ground support for shaft centralizing.
15 2. It shaft rear end can be moved up and down with this fixture which
facilitate easy alignment with input shaft flange of reduction gear box.
3. Simple design and easy to operate
Detail Description of the Invention
5 . Construction:
This fixture is designed to support the high speed .shaft rear end flange
‘and also provide up and down movement to rear end to facilitate
centralizing of the shaft with gas turbine. In the fixture support wheel
(1) is attached to upper support arm (2) with help of support pin (9)
10 and upper support arm (9) is attached to bottom support arm (3) using
a screw rod (8), nut (5) & handle (4). Bottom support arm (3) is
attached to support plate (7) and mounting plate (6). Nylon wheel is'
attached with fixture with pin this facilitates the free rotation of the
wheel during manual rotation of thé shaft. This arrangement facilitates
15 the supporting of overhanging flange of high speed coupling shaft by
Function :
This fixture is designed in such a way that it takes support from
5 module wall itself to support the high speed shaft. After assembly and
installation of gas turbine in gas turbine m‘odule the front end of the
shaft will be connected to gas turbine and rear end of the shaft will
protrude (overhung) outside of rear module wall. This overhung will
cause strain in the coupling between gas turbine and shaft when rear
10 end of the shaft is not connected to reduction gear box input shaft.
Hence there is need to support the shaft at rear end. Once shaft
assembly with gas turbine is completed in the module this fixture will
be mounted on the rear wall (10) on the module on the mounting holes
(11) provided on the wall with help of two mounting plates (6) of the
15 fixture. Handle (4) of the fixture will be then rotated to raise the upper
support arm (2) with help ‘of nut (5) and screw rod (8) in such a way
the nylon wheel (1) of the fixture touches the overhung shaft flange.
Handle will be turned further to raise the rear end of the shaft (12) in
such way that free hand rotation of the shaft is possible (shaft
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20 cent reline is aligned with gas turbine cent reline). Nylon roller on either
side of the shaft flange also restricts side wise movement of the shaft
and helps in centralizing. This arrangement makes module completely
independent during handling without any disturbance to the shaft
center line. Figure 2 illustrates the application of the fixture; Fixture
25 eliminates the need of any ground or crane support for the shaft,
makes gas turbine module independent during handling and storage
We Claim,
1. A fixture designed and manufactured for support of high speed
shaft assembly of Gas Turbine comprising:
a support wheel (1);
a upper suppon arm (2);
a bottom support arm (3);
a handle (4);
a nut (5);
a mounting plate (6);
a support plate (7);
a screw rod (8); and
a support pin (9), characterized in that, support wheel (1) is
attached to upper support arm (2) with help of support pin (9) &
upper support arm (9) is attached to bottom support arm (3) using
a screw rod (8), nut (5) & handle (4) and bottom support arm (3) is
attached to support plate (7) and mounting plate (6) to facilitate the
supporting of overhanging flange of high speed coupling shaft by
taking support from module wall when gas turbine module is not in
use and help in center line alignment of shaft by providing up and down movement of shaft .