Check brushes and springs for cracks or breaks

TM 9- 2920- 224- 34&P

DISASSEMBLY OF THE GENERATOR ASSEMBLY - CONTINUED

0008 00

NOTE

Spring tension must be checked at working deflection.

ax. Check brushes and springs for cracks or breaks. Check brushes and spring tension for conformity to

dimension limits. New brush length shall be within 1.187 to 1.188 inch. Field wear limit is 0.688 inch. Spring

tension shall be between 52 to 60 oz (at working deflection). If any brushes or springs are defective, replace

entire set with brush kit.

ay. Inspect generator support assembly for cracks and distortion. Replace if defective.

az. Check bearing bore in generator support assembly. Replace end plate if inside diameter of bearing bore does

not conform to 2.4406 to 2.4409 inch limits.

ba. Inspect support assembly for scratches, burrs, and nicks on machined surfaces. Minor defects shall be

repaired if the defect affects fit or function.

bb. Inspect threads in tapped holes in support assembly for damage. Replace generator support assembly if

threads are stripped.

bc. Remove six self--locking nuts (53) from studs on flange of shaft assembly (3) and remove pressure damper

plate retainer (54). Discard nuts.

bd. Remove six compression helical springs (55), pressure damper plates (56), and friction damper plate

assembly (57) from shaft assembly (3).

be. Visually check all parts of generator drive shaft for cracks, excessive wear, and distortion. Bronze friction

surfaces must not be worn excessively; must be smooth and free of corrugations and score marks.

Corresponding steel surfaces must also be free of score marks and wear patterns that can be detected by a

straight edge placed on surface and viewed in front of a strong light. Replace worn, scored, or distorted parts.

bf. Check all six damper springs for cracks or distortion. Replace all six springs if one or more springs show signs

of failure. The free length of compression helical spring shall be within 0.4800 to 0.5000 inch with a field wear

limit of 0.4800 inch. The spring maximum solid height shall be within 0.3400 to 0.3500 inch with a field wear

limit of 0.3400 inch. Spring load at 0.375 inch length shall conform to 68 to 80 Ib with a field wear limit of 68 lb.

bg. Check damper plate for cracks or distortion. The thickness of the damper plate at wear surfaces shall conform

to 0.1231 to 0.1463 inch limits with a field wear limit of 0.1100 inch. The thickness of the spring backup

damper plate shall conform to 0.1563 to 0.2187 inch limits with a field wear limit of 0.1490 inch. Replace if

defective.

0008 00- 15