SB--7--627 Page 15
SECTION 5
MAINTENANCE
GEAR INSPECTION
Inspection of the timing gears may be accomplished by
removing the gear case. Refer to FIGURE 9. Prior to
removing the gear case the oil should be drained from
the gear case sump. On units with force feed lubrica-
tion, remove the oil pump adaptor plate with the oil
pump attached using the tapped jacking holes in the
plate. After removing gear case flange bolts, the gear
case may be removed. Be sure to support the gear
case adequately while removing. Timing gears and
gear end bearings are now exposed.
On completion of maintenance work, be certain that the
oil pump and/or the gear case is returned to the original
position. Use a paste type gasket compound on the
mating surfaces. Always relubricate before starting.
IMPELLER INSPECTION
Series 8000 impellers can be inspected through the
intake and discharge ports. This will reveal such
conditions as out of time, excessive or insufficient
clearances, abrasion of parts from passing foreign
material, etc.
REPAIR
Assembly
When rotation of the impellers is
required in the assembly process,
insure that all personnel are clear of
lobes and gears to guard against
serious injury.
TIMING
The impellers of the unit are separated by pre--deter-
mined minute clearances built into the machine. The
timing of a unit is the setting of one impeller with respect
to the other so they do not touch or knock during normal
operation. The impellers are held ’in time’ by timing
gears which are bolted to a timing hub, which in turn is
secured to the serrated impeller shaft by a lock washer
and locknut. Retiming is necessary to restore proper
impeller clearances after a unit has been jammed and
the removal of the strain or foreign material does not
stop the knocking or pounding during operation.
FIGURE 9 -- LOCATION OF TIMING GEAR BOLTS
G & H
J & K