Page 296 - Machinery Component Maintenance

278 Machinery Component Maintenance and Repair

Balancing Keyed End-Drive Adapters

An adapter for a keyed rotor shaft should be provided with two 180"
opposed keyways. The correct procedure for balancing the adapter de-
pends entirely on which of the two methods was used to take care of the
mating keyway when balancing the component which, on final assembly,
mounts to the keyed shaft end of the workpiece being balanced.

Half-Key Method
This is the method most commonly used in North American industry.
Shafts with keyways, as well as the mating components are individually
balanced with half-keys fitted to fill the void the keys will occupy upon
final assembly of the unit (see Figure 6-22A). To balance the end-drive
adapter using this method, proceed as follows:

A. Rotor shaft with
ha 1 f -key.

B. End-drive adapter
mounted on rotor shaft;
match-marks in line.

C. End-dr ive adapter
indexed 180" on rotor
shaft; match-marks on
opposite sides.

Indicates keys required

Figure 6-22. Half-key method.