and record this amount. (We will refer to this distance
clearances. The drive gear clearance inspection is very
important because you must check for proper starter
as measurement A.)
drive engagement to the reduction gear drive assembly.
2. Measure the distance from the reduction gear
mounting flange to the face of the driven gear
PTO Shaft. The PTO shaft inspection is part of an
(measurement B) and record this amount. (We will refer
overall maintenance check in which you will measure
to this distance as measurement B.)
the turbine-to-reduction gear alignment. There are two
other components that are associated with the PTO shaft
3. You already have the measurement for the
that you will be responsible to inspect-the midbearing
predetermined amount of the starter shaft travel, which
oil spray nozzle and the turbine speed pick up.
we will refer to as measurement C. Now that you have
measurements A, B, and C, you will need to calculate
Midbearing Oil Spray Nozzle. You should
whether the addition or removal of shims is necessary.
periodically remove and inspect the oil spray nozzle to
In most cases, due to wear of gear teeth, the addition of
ensure the nozzle holes are clear of debris and that the
shims will be necessary.
nozzle has been providing a proper oil supply to the
4. Add measurements A and C together and record
the total (measurement D). Now subtract measurement
Turbine Speed Pick Up. The last component in the
B from measurement D and record this amount. (You
PTO shaft you should check is the turbine speed pick
will usually subtract because of wear.)
up. You should normally clean and inspect this
component to make certain the measuring surface is
5. The last amount you must determine is the
clean and undamaged.
distance that needs to be compensated for with shims.
Select the shims and install and repeat the measurement
procedure until the proper clearances are achieved.
inspection we will discuss is the reduction gear to
generator shaft. This inspection is not difficult or
The procedure we have just described is an
involved. Your main concerns will be inspecting for any
overview and is not intended to replace the procedures
loose flange bolts or foreign objects rubbing against the
found in the PMS or another approved technical
shaft. You should also make sure the shaft is free of dents
or dings that could affect the shaft's balance.
PTO Shaft. To achieve proper PTO shaft
ALIGNMENTS AND ADJUSTMENTS. As we
alignment (turbine to reduction gear), you must make an
adjustment by changing the turbine's position on its
talked about in the previous section, the proper
mounts. Usually the addition of shims to the turbine's
alignment of reduction gear components is very crucial.
pedestal mount is necessary to bring the engine back to
Since we have already discussed the components that
the proper alignment height. Since this procedure can be
require aligning, let's talk about the adjustments needed
very involved, we recommend you consult the
to make these alignments correct.
appropriate technical references.
Starter. The proper engagement of the starter is
Generator Drive Shaft. This procedure is very
necessary for the smooth transmission of power from
difficult to perform. Although you may be asked to
the starter to the reduction gear. Considering the price
assist, the work will be accomplished by a repair facility
of a starter and the fact that you have never done this
and sometimes under the close supervision of a
procedure before, you will probably be pretty nervous
NAVSEA representative. The key things that make this
on your first try.
job so difficult are the following conditions:
Essentially, the adjustment is made by the addition
1. The equipment is very heavy, and experienced
or removal of shims on the backside of the reduction
rigging is required.
gear drive gear. This adjustment is made to ensure a
predetermined distance between the two gears is
2. Changes in ambient air temperature will
maintained before engagement. This distance is based
adversely affect accurate measuring
on the maximum amount of travel of the starter drive
gear. The space between the two gears is not very hard
TROUBLESHOOTING AND REPAIRS.
to calculate if you use the following steps:
Troubleshooting a problem on the generator's reduction
1. With the starter removed, measure the distance
gear or its support components can sometimes be
from the starter mounting flange to the face of the gear
difficult. The hardest problem for you to isolate will be