complete the loop. The lube oil service system
lockout control on the SSS clutch. It prevents
includes the following major components:
initiation of the clutch engagement sequence by
displacing the pawls from respective ratchet rings.
The lube oil sump
This mechanism is incorporated in the output
assembly and consists of a bevel pinion meshed
with an actuating ring (ring gear). A special tool
Two motor-driven lube oil service pumps
is provided that unlocks and turns the pinion.
An attached (driven by the MRG) lube oil
service pump
Lubrication
Lube oil from the MRG lube oil supply header
A lube oil cooler
is supplied to the rotating parts of the clutch
through the center of the HS pinion. The rotating
A duplex lube oil filter
parts of the clutch and the thrust bearings absorb
end thrust between the input shaft and the out-
A lube oil unloading valve
put connection of the MRG. The parts and bear-
ings are supplied with oil through the center of
A lube oil heater
the input shaft. The oil then discharges radially
outward through a third hole, while a fourth feed
Interconnecting piping to the lube oil fill and
hole lubricates the relay sliding surface.
transfer system
OIL DISTRIBUTION
The three pumps take suction from the lube
oil sump through check valves. The check valves
The main lube oil service system supplies lube
maintain the pump's prime and prevent reverse
oil to the MRG and accessories through the main
flow through a secured pump. The pumps
lube oil header. The headers are located at the top
supply oil under pressure to a common line, where
of the gear case. Gear and pinion teeth are
the unloader valve returns oil in excess of demand
lubricated and cooled by spray nozzles arranged
to the sump. Oil from the common line flows to
to direct oil across the full face width at the gear
the lube oil cooler, where its temperature is
mesh. Oil flow to journal bearings and the main
reduced to approximately 120F. From the cooler,
thrust bearing is controlled by orifice plates. The
oil flow is divided into two paths, one to supply
orifices are sized to allow sufficient oil flow for
the MRG and the other to supply the two LOSCA
lubrication, but they restrict excessive flow if
coolers. Oil to the MRG flows through the duplex
extreme bearing wear or bearing failure occurs.
lube oil filter into the MRG lube oil header. From
The orifice plates are installed at the flanged
the MRG header, oil is distributed to lubricate and
cool the reduction gear components, the brake/
connection to each bearing, except in the case of
the HS pinion and input shaft bearings. Orifice
clutch assemblies, and the thrust bearings. The
plugs are installed in the bearing seats in these
oil then returns to the sump. Oil to each LOSCA
locations. Each bearing is equipped with a sight
passes through a pneumatically controlled
flow indicator and a bimetallic thermometer for
(unloading) valve. This valve controls oil flow to
local monitoring of oil flow and bearing oil
the synthetic lube oil cooler to regulate
temperature. Nominal lube oil pressure is 15 psig.
temperature at the synthetic oil discharge. Service
Minimum oil pressure at the hydraulically most
system lube oil from the LOSCAs join in a
remote bearing is 5 psig. All ship classes have the
common line to return to the MRG sump.
same basic lube oil service system. Again, we will
cover them separately because of the differences
Pressure regulation of the lube oil service
in design and setup.
system is accomplished by control of the unloader
valve. The controller senses pressure at the inlet
connection to the MRG oil header and regulates
DD, DDG-993, and CC Lube Oil Systems
the unloader to maintain 15 psig minimum at the
The lube oil service system is a pressure feed
header inlet. During normal operation, the motor-
system that delivers oil under pressure to the MRG
driven pumps are controlled by the ECSS. They
header and to each lube oil storage and
can be cycled by a controlled sequence to main-
conditioning assembly (LOSCA). All oil returns
tain adequate oil pressure at the MRG header
inlet.
to the supply reservoir (the MRG sump) to
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