AERO® Semi-Custom Central Station Air Handler 39M: Fan Shaft Bearing Removal

Fan Shaft Bearing Removal

• Isolate the unit from the system by closing dampers to prevent “pin wheeling.” Tie off the fan wheel to prevent rotation.

• Lock open and tag electrical disconnect.

• Enter through fan section access door or remove panels as required.

• Loosen motor base to frame bolts. Adjust motor to release belt tension and remove belts. Do not stretch belts over sheaves. Damage to belts can result.

• Remove bolts on bushing of fan shaft sheave, insert bolts in jacking hole provided on bushing and slowly jack bushing from sheave. Remove bushing and sheave.

• Loosen bearing holddown bolts, block shaft up.

• Loosen bearing setscrews and locking collar, and remove holddown bolts.

• NOTE: To facilitate easy removal of setscrew fastened wheels, sheaves, or bearings, remove the setscrew completely. Taking care not to damage threads, insert a flat ended drift or punch, tap lightly and carefully return the material displaced on the shaft by the setscrew to its original place.

• Remove bearing while observing the following precautions: a. Make certain fan shaft surface is not rough or scored. If so, clean up surface with fine emery cloth. d. Add a few drops of oil after cleanup of shaft end.

• ! CAUTION: It should not be necessary to drive a new bearing onto shaft. If light tapping is needed, do not tap against outer race. Equipment damage may result.

• Check fan shaft diameter at bearing mount. If worn by more than 0.001 in. below nominal, shaft should be replaced.

• Install new bearing, tighten holddown bolts, and then tighten bearing locking collar or setscrews.

• Make certain fan wheel does not rub sides of fan housing after installing new bearings.

• Recoat fan shaft with a rust inhibitor or grease.

• Replace sheave and belts. Adjust and align as described in Installation, Sheaves and V-Belts sections.

• Replace access panels.

• Restore electrical power.