6-10.
How long, after securing the main
reduction gear, should you circulate the
lubricating oil through the system?
1.
15 minutes
2.
Until the temperature of the oil is
the same as the reduction gear casing
3.
Until the temperatures of the oil and
reduction gear casing are
approximately the same as the
engineroom temperature
4.
30 minutes
6-11.
How can you eliminate the condensation of
water from the inside of a reduction gear
casing?
1.
Keep the gear oil heated until
condensation evaporates
2.
Ensure the gear oil circulates at all
times so that the water may be
centrifuged out
3.
Renovate the gear oil in a purifier
while a cooler is operated and the
gear is jacked
4.
Allow the gear oil to remain
6-17.
unstirred so that water may settle
to the bottom of the casing
6-12.
Satisfactory operation of which of the
following components should keep the lube
oil in good condition?
1.
Centrifuge and blower
2.
Strainer and filter
3.
Spray nozzles and heater
4.
Purifier and settling tanks
Question 6-13 is to be judged True or
False.
6-13.
Reduction gear lube oil samples should be
taken and sent to a naval shipyard
laboratory only once a quarter to be
tested for contamination.
6-14.
What substances cause gear lubricating
oil to emulsify?
1.
Freshwater and seawater
2.
Fatty acids
3.
Air bubbles
4.
Insoluble minerals
6-15.
What should be done
begins to emulsify?
if the lube oil
1.
The plant should be stopped and the
oil removed
2.
The oil should be heated to just
below the boiling point
3.
The oil should be centrifuged to get
rid of the water and the acid
4.
The oil should be allowed to settle
to get rid of the water and the acid
6-16.
Assume that during operation, the
lubricating oil level in the sump of the
reduction gear rises high enough to come
into contact with the bull gear.
What is
likely to result if this situation is NOT
corrected?
1.
The oil will overheat
2.
The oil will become emulsified
3.
The oil will be trapped in the sump
4.
The oil will be contaminated with
water
What should you do first in case of a
burned-out pinion bearing?
1.
Stop the engine
2.
Align the gear teeth
3.
Stop the main propeller shaft
4.
Slow down the engine
6-18.
What is the first probable cause to be
considered when a vibration occurs in a
reduction gear that previously had been
operating properly?
1.
Bent propeller shaft
2.
Bent propeller blade
3.
Unbalanced bull gear
4.
Misaligned pinion gear
Learning Objective: Explain the
methods of checking bearing
clearances and identify the main
troubles encountered with reduction
gear bearings.
6-19.
Which of the following information,
recorded in prescribed engineering
records, should be available for checking
the alignment of the reduction gear?
1.
Gear teeth root clearances and
backlash
2.
Thrust bearing clearances and
settings
3.
Original bearing clearances and crown
thickness
4.
All of the above information
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