Description / Abstract:
Characteristics of horizontal hard-bearing balancing machines
are described which make such machines suitable for gas turbine
rotor balancing.
This document specifies:
a. General dimensions and capacities
b. Performance requirements
c. Balancing speed ranges
d. Drive power requirements
e. Balancing machine drive adapter flange dimensions
f. Test procedures
Proving rotors and associated test masses required for the
performance tests are described in ARP4162.
Test procedures are described in detail and test log samples
along with a polar diagram for evaluating the test results are
furnished.
The predecessor document ARP587, ISO 2953, and the available
technology of hard-balancing machines have been considered in the
preparation of this document.
This document was developed for hard-bearing balancing machines
but may also be used for existing soft-bearing balancing
machines.
Purpose:
The purpose of this document is to delineate the technical
specifications for horizontal rotating type, hard-bearing balancing
machines for measuring the amount and angle of unbalance
corrections required in one or more than one transverse planes to
balance gas turbine rotors. (For Glossary of Terms and
Nomenclature, see ISO 1925.)
Hard-bearing machines have been used for gas turbine rotor
balancing for several years. They have largely replaced
soft-bearing machines. Hard-bearing machines provide permanent
calibration (see ISO 1925) with first-run readout, simpler
operation, easy adaptation to computerization, and eliminate
support locking requirements and windage fluctuations.
This document also delineates performance tests to ensure
compliance with the document.
This document was prepared to give a general description of
balancing equipment capable of balancing gas turbine rotors either
now in service or to be put into service in the foreseeable future.
Standardization of balancing machine to rotor interfaces is
intended to enable a set of tooling for a particular component to
be used on a variety of machines in one capacity range.
This document may also be used as a general specification for
purchasers in procuring suitable horizontal balancing machines.
The performance and test requirements may be used for periodic
tests and/or after repairs that my have affected the balancing
machine's performance. The test procedure shall be the same as
described in this document.
The performance and test requirements have been written in terms
of "emar" (minimum achievable residual specific
unbalance), and A-units rather than fixed physical values, such as
grams, millimeters. Ounces, or inches. (See ISO 1925).