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OIL SYSTEM General The oil system consists of pressure system

VIEWS: 5 PAGES: 10

  • pg 1
									           Dornier 328Jet - Oil System




OIL SYSTEM

General
The oil system consists of a pressure system, a scavenge system, a breather system and
associated pressure temperature sensors and switches. The main components of the oil system
are:

– the oil tank,
– four oil pumps (one pressure and three scavenge)
– pressure adjusting and cold start valve
– the oil filter assembly
– fuel / oil heat exchanger.

The oil tank is an annular cavity that is integrated in the engine intermediate case structure. The
tank outlet is located at the bottom intermediate case strut and has an integrated perforated
screen filter within a transfer tube. The oil tank is a ”hot type” as scavenge oil is not cooled
before returning to the tank. The oil filler neck and cap are located on the intermediate case. A
sight glass is provided for checking the engine oil level. The pressure and scavenge pumps are
of the positive displacement gear type.

Pressure Oil System
Oil is drawn from the tank through a passage in the intermediate case to the pressure pump and
to the oil system pressure adjusting and cold start valve (PAV). The PAV maintains a pressure
differential between oil feed pressure and bearing scavenge pressure. During cold weather
starts where initial oil pressure is high, the PAV will relieve excess pressure back to the pressure
pump inlet. From the pressure pump, the oil passes through a filter and a fuel/oil heat
exchanger and is subsequently supplied to the bearing compartments of the inner LP shaft
bearings No. 1 and 4, the outer HP shaft bearings No. 2 and 3 and the accessory gearbox tower
driveshaft bearing.
The oil pump drive train is arranged such that the pressure pump will not be driven in the event
of a failure of any of the scavenge pumps. This prevents oil flooding the engine core should an
oil scavenge pump become inoperative.

Scavenge Oil System
The system has three scavenge pumps. The pressurized oil that is supplied to bearing
compartments No. 3 and No. 4 is returned to the accessory gearbox by an individual scavenge
pump for each bearing. The scavenge oil from bearing compartments No. 1 and No. 2 is
drained by gravity to the sump of the accessory gearbox. The scavenged oil from the sump of
the accessory gearbox is returned to the oil tank by the third scavenge pump.

Breather System
Breather air from engine bearing compartments and the AGB is vented overboard through an
impeller type centrifugal air/oil separator installed on the alternator gear shaft in the AGB.
The engine has a differential oil pressure indicator that is located above the oil filler cap which
indicates any over–pressure condition in the AGB. A popped–out red button indicates an
over–pressure condition in the AGB.




                                           Page 1
                    Dornier 328Jet - Oil System



Pressure and Sensors and Switches and Temperature Sensor
Sensors and switches on the engine monitor the oil pressure and oil temperature and provide
the information for indications on the EICAS. The following sensors and switches are fitted to
each engine:

–   pressure sensor (EICAS bar are digital readout)
–   oil filter differential pressure switch (warns of oil filter blockage)
–   low pressure switch (oil prerssure warning on Reed Warning Panel)
–   temperature sensor (EICAS bar and digital readout).




                                                   Page 2
Dornier 328Jet - Oil System




                      Oil System – Schematic




                              Page 3
Dornier 328Jet - Oil System




      Oil Tank Filler and Over Pressure Indicator




                              Page 4
         Dornier 328Jet - Oil System




OIL TEMPERATURE DISPLAY
Oil Temperature Analog Scale
The normally white horizontal scale is augmented with amber and red bands, depending on the
operating range.


                     Color                 Lower Limit              Upper Limit
                      Red                        –54° C                      –40° C
                  Amber/Red
                                                 –40° C                     16.5° C
                   ( Note 1 )
                     White                        16° C                   135.5° C
                  Amber/Red
                                                 135° C                   143.5° C
                   ( Note 2 )
                      Red                       >143° C           pointer stops at 150° C

               NOTE: 1. Color band changes to red if TLARC valid, N2 low and
                         WOW
                      2. Color band changes to red if operating in this range for
                         more than 90 seconds.

Oil Temperature Digital Display
This display shows a digital value for temperature. The color of the digits matches the analog
scale pointers color.




                                       Page 5
Dornier 328Jet - Oil System




EICAS – Left and Right Engine Oil Temperature Indicator



                              Page 6
Dornier 328Jet - Oil System




Engine System Page – Left and Right Engine Oil Temperature Indicator



                              Page 7
                  Dornier 328Jet - Oil System




OIL PRESSURE DISPLAY
Oil Pressure Analog Scale
The normally white horizontal scale is augmented with amber and red bands, depending on the
operating range.



    Lower Limit          Upper Limit              Pointer Color            Band Color
                                                    Amber/Red               Amber/Red
       0 PSI               10.5 PSI
                                                     ( Note 1 )              ( Note 1 )
                                                    Amber/Red               Amber/Red
      10 PSI               20.5 PSI
                                                     ( Note 2 )              ( Note 2 )
                                                   White/Amber             White/Amber
      20 PSI               36 PSI
                                                       (Note 3)             (Note 3)
      35.5 PSI            110.5 PSI                      White                None
                                                    Amber/Red               Amber/Red
     110.5 PSI           220.5 PSI
                                                     ( Note 4 )              ( Note 4 )
      220 PSI                                              Red                 Red
 NOTE: 1. Color band changes to Red if 0 PSI  POIL  10.5 PSI after 25 sec.
       2. Color band changes to Red if 10 PSI  POIL  20.5 PSI after 90 sec.
       3. White at N2 < 80% and amber at N2  80%.
       4. Color band changes to Red if 110 PSI  POIL  220.5 PSI after 90 sec. and
          TOIL > 16° C.


Oil Pressure Digital Display
This display shows a digital value for pressure. The color of the digits matches the analog scale
pointers color.




                                                Page 8
Dornier 328Jet - Oil System




         EICAS – Left and Right Engine Oil Pressure Indicator



                              Page 9
Dornier 328Jet - Oil System




Engine System Page – Left and Right Oil Pressure Indicator




                          Page 10

								
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