FIELD OF INVENTION
The present invention generally relates to a turbo-generator operated in an
industrial or utility environment. In particular, the invention relates to the bearing
shells employed to support the rotors and provided with means to maintain
hydro-static oil pressure during initial start up and shut down. More particularly,
the invention relates to a method for hydraulic testing of bearing shells in a
turbogenerator (TG). The invention further relates to a device to carry out
hydraulic testing of bearing shells in a turbogenerator.
BACKGROUND OF THE INVENTION
Turbo generator rotor train consists of a set of rotating shafts, coupled together.
The individual rotors are supported on bearing shells, which in turn are located In
the respective bearing housings. During machine operation, the interface
between the bearing shell and rotating journal is provided with a hydrodynamic
oil film that is maintained continuously. Hydrodynamic oil film is maintained
based on the speed of rotation of the shaft, its weight, properties of oil used,
and oil clearances. However, during staring or stopping of a TG set, a film with
dynamic characteristics, adequate enough to carry the rotor weight do not form
due to lower speed of shaft rotation. It is, however, necessary to have an oil film
maintained between the shell and journal to prevent metal to metal contact.
Hence additional provision is given to meet the requirement. This is done by
supplying oil at a very high pressure through oil passages machined directly
below the rotor. As the oil is supplied at a high pressure, only during start up and
shut downs, the oil circulation path is different from the lube oil inlet path where
the supply pressure is relatively very less.
The high pressure oil path ensures oil supply at requisite high pressure and
disallows leakage through any of the supply lines. In view of this requirement,
the high pressure oil line is checl