Tests of Laser Metal Removal for Future Flexible Rotor Balancing in Engines

This paper describes recent developments in the flexible rotor balancing technology area, with particular emphasis on methods for the addition and removal of correction weights. The currently existing Multiplane-Multispeed Balancing procedure permits one-step balancing of final shaft-bearing assemblies simultaneously in a number of planes and at a number of speeds. Temporary addition of trial weights to the rotor, and the addition or subtraction of permanent corrections, are presently performed manually in the balancing process. The addition of a computer-controlled laser device to the balancing system shows promise of eliminating direct operator contact with the rotor in the balancing process, and thus could provide a considerable increase in the precision level at a critical step in the procedure. Preliminary investigations show that design-incorporated provision of suitably-located balancing planes on the rotor, and access to those planes from outside the machine casing through portholes, should permit balancing of machine rotors in place. Check-balancing of rotors without the need for stopping the rotor appears feasible.