FIELD OF INVENTION
The invention relates to an apparatus with improved on load stability and safety
for lifting and shifting gas turbine rotors. More particularly, it relates to a lifting
apparatus for Gas turbine rotors with improved safety and stability.
BACKGROUND OF THE INVENTION
Gas turbines are rotary internal combustion engines which are used as prime-
movers in power plants and various process industries. These are axial flow
machines which can be divided into two parts:
• Stator- comprises of horizontally split casing with stator vanes.
• Rotor-build up compressor and turbine rotor assembled together as a
single unit.
During assembly, the lower half of casing is kept on a base and complete rotor is
assembled into the casing. During major inspections, the rotor is to be lifted out
for thorough inspection. Since the clearances between rotor and stator blades
are very tight, utmost care should be taken while lifting the rotor. Any instability
may result in damage to rotor as well as stator components. To carry out this
critical operation, lifting beams are used.

Gas Turbine rotor design makes provision for lifting only at its ends. Since the
largest moving parts viz. first stage compressor blades and last stage turbine
buckets are in the vicinity of the lift location, use of a Spreader Beam is essential
to avoid their crushing. Also the equipment should provide sufficient stability to
the rotor during the lift to avoid touching the stator component. Another
requirement is provision for adjustments in individual hook heights to
accommodate minor variation in sling lengths. The distance between the hoist
and load (due to top rigging) gives these beams greater stability.
The present practice of lifting gas turbine rotors is with the help of a single point
lifting of spreader bar. The spreader bar is connected to the hoist with the help
of a single point provided at the centre of the beam. Fig.1 shows the present
practice of lifting gas turbine rotor.
An inherent problem with this design is, if this beam is not in a horizontal
position during operation, the inclined rotor orientation can cause excessive
loading in one direction, which may result in an accident and irreparable damage
to the rotor. Fig.2 shows the probable behavior of beam with single point lifting
in unforeseen circumstances.

The present invention discloses lifting equipment for gas turbine rotors with two
points lifting of the spreader bar, with load hooks which can be repositioned to
suit both the unit rotor and the compressor and turbine rotor individually.
Accordingly there exists a need to make a lifting apparatus which can eliminates
the disadvantages of prior art.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose an apparatus with improved
on load stability and safety for lifting and shifting gas turbine rotors which
eliminates the disadvantages of prior art.
Another object of the invention is to propose an apparatus with improved on
load stability and safety for lifting and shifting gas turbine rotors which is capable
of keeping the apparatus on load always horizontal providing an improved
stability and safety during lifting.
SUMMARY OF THE INVENTION
Therefore, the present invention advantageously provides a lifting apparatus
comprising an I-beam (1), connected to the hoist with slings (5) at two points,

such that every time the apparatus (A) is lifted it is horizontal, providing stability
and safety during lifting the gas turbine rotors. The load connectors are
positioned at the end of the beam so as to match the center of gravity of rotor
with that of spreader bar.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.1 - shows lifting of gas turbine rotor with an equipment with single point
hoisting to the crane
Fig.2 - shows design deficiencies in single point lifting
Fig.3 - shows new embodiment of lifting equipment for gas turbine rotors with
two point lifting
Fig.4 - shows carriage assembly for slings
Fig.5 - shows carriage assembly for lifting rotor
Fig.6 - shows usage of current design for lifting individual turbine rotor
Fig.7 - shows usage of current design for lifting individual compressor rotor
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Unless otherwise defined, technical and scientific terms used herein have the
same meaning as commonly understood by one of ordinary skill in the art to

which this invention pertains. It should be understood that the materials,
methods and examples given are illustrative in nature only and not intended to
be limiting. Accordingly, this invention may be embodied in many different forms
and should not be construed as limited to the illustrated embodiments ser forth
herein. Other features and advantages of the invention will be apparent from the
following detailed description. As such an exemplary embodiment of the
invention as depicted in the accompanying drawings will now be explained in
details. However there can be several other embodiments all of which are
deemed covered by this specification.
The apparatus for lifting gas turbine rotor (Fig 3) consists of the following main
components:
1. I-Beam (1)
2. Carriage assembly for lifting rotors (2)
3. Carriage assembly for slings (3)
4. Stopper plate (4)
5. Slings (5) and (11)
The lifting apparatus (A) comprising of an I-beam (1) is secured to the crane
hook (6) with the help of slings (5), which passes over the sheave (7) assembled
in the carriage (14). The carriage assembly for slings (3) is shown in fig.4. This
assembly (3) consists of a carriage (14) having a sheave (7) fixed to it by pin

(15). To prevent the axial movement of the carriage assembly, a stopper plate
(4) is assembled on the top of I-beam (1) as shown in Fig.1.
The rotor (10) is lifted with the help of slings (11), which are rigged to the lifting
hook (8) at two ends. The carriage assembly (2) for lifting rotor is shown in fig.5.
This carriage assembly (2) consists of a carriage (16) having lifting screw (13)
fixed to it by pin (17). The lifting screw (13) is provided with a stopper (9) and a
lifting hook (8) which are kept in position by a nut (12). The stopper (9) prevents
the slippage of slings (11) over the hook (8). A nut (12) is tightened over the
lifting screw (13), to secure the hook (8) in its place. Screw arrangement helps in
vertical adjustment of the hook (8) to fine-tune the rotor horizontal position
while lifting. The position of carriage assembly is fixed with the help of M39
bolts. The spreader bar or the I-beam (1) can be used to lift individual
compressor and turbine rotor as shown in fig.6 and fig.7.

WE CLAIM
1. An apparatus with improved on load stability and safety for lifting and
shifting gas turbine rotors comprising:
an I-beam (1) connected to a crane hook (6) by slings (5);
the said slings passing over a sheave (7) assembled in a carriage (14);
a carriage assembly (2) consisting of a carriage (16) having a lifting screw
(13) fixed to it by pin (17);
a carriage assembly (3) consisting of a carriage (14) having a sheave (7)
fixed to it by pin (15);
at least one stopper plate (4) assembled on the top of I-beam (1) for
preventing the axial movement of the carriage assembly (3);
a plurality of slings (11) rigged to the lifting hooks (8);
a lifting screw (13) providing vertical adjustment of the hook (8);
characterised in that the spreader bar or I-beam (1) is connected to the
slings (5) at two points for making the apparatus stable and safe.
2. An apparatus (A) as claimed in claim 1, wherein at least one stopper (9) is
adapted in carriage assembly (2) for preventing slippage of slings (11)
over the hook (8).

3. An apparatus (A) as claimed in claim 1, wherein a nut (12) is tightened
over the lifting screw (13) for securing the hook (8) in its place.

A lifting apparatus (A) with improved on load stability and safety for lifting and
shifting gas turbine rotors consists of an I-beam (1) connected to a crane hook
(6) by slings (5) which passes over a sheave (7) assembled in a carriage (14). A
carriage assembly (2) for lifting rotors consists of a carriage (16) having a lifting
screw (13) fixed to it. A carriage assembly (3) for slings (5) consists of a carriage
(14) having a sheave (7) fixed to it by pin (15). A stopper plate (4) is assembled
on the top of the I-beam (1) when slings (11) are rigged to the lifting hooks (8).
The lifting screw is provided for vertical adjustment of the hook (8). The I-beam
(1) is connected to the slings (5) at two points for making the apparatus stable
and safe.