B. Distribution
(1)
The subsequent components make the oil distribution system:
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the oil pressure pump,
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the oil scavenge pumps,
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the pressure relief valve,
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the de-oiling solenoid valve,
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the oil cooler,
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the oil filters,
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the external and internal oil lines.
(2)
Oil Pumps The oil pumps are is installed on a pad on the accessory drive gearbox (Ref. 49-26-00). The oil pressure pump removes the oil from the oil reservoir by suction. It supplies the lubrication oil to the oil cooler and the pressure oil filter. The temperature regulated and filtered oil is supplied to the lubrication points of:
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the APU front bearing,
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the APU rear bearing,
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the gearbox gears and its bearings,
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the cooling fan,
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the APU generator.
When the oil pump pressure gets to high, a pressure relief valve
opens. This allows the oil to return to the oil sump.
The scavenged oil from the rear bearing and the generator falls into the sump and is returned to the oil reservoir with two oil scavenge pumps. The generator scavenge oil is filtered from the generator scavenge oil-filter before it enters the sump. The oil which lubricates the gears and bearings of the gearbox, is returned to the reservoir by gravity.
(3)
Oil Cooler The oil cooler decreases the temperature of the oil. It is an oil/air heat exchanger which receives the cooling air from the cooling fan (Ref. 49-52-00). A serviceable oil cooler will keep the oil temperature within the limit during all operation conditions. A bypass valve and a check valve regulate the internal pressure and the oil flow through the oil cooler. A bypass valve is installed between the oil cooler inlet and outlet and the check valve is installed at the oil outlet of the oil cooler.
(4)
Filters The distribution system has two oil filters:
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the lubrication oil filter,
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the generator scavenge oil-filter. The filters remove unwanted materials from the oil. The pressure oil filter cleans all the lubrication oil before it is supplied to the lubrication points. The generator scavenge oil-filter cleans unwanted materials from the generator scavenge oil. This makes sure that the generator does not give contamination to the oil in the oil reservoir. Differential pressure indicators on the filter housings are latched out if the filter element is clogged. You can set the differential pressure indicator again manually. The oil filters have a filter bypass valve which opens when the filter element is fully clogged. Then the oil does not flow through the filter element, but the APU receives lubrication oil.
APU Oil System - Schematic Figure 002 (SHEET 1)
R EFF : 106-106, 108-149, 211-299, 301-399, 49-91-00Page 6 Config-3 Aug 01/05
CES
APU Oil System - Schematic Figure 002 (SHEET 2)
R EFF : 106-106, 108-149, 211-299, 301-399, 49-91-00Page 7 Config-3 Aug 01/05
CES The generator scavange oil-filter and the lubrication oil-filter have an electrical differential pressure switch whichalso transmits a signal to the ECB when the filter is blocked. The ECB stores the fault in its non-volatile memory.
(5) De-oiling Solenoid Valve The de-oiling solenoid valve reduces the oil pressure pump load during the APU start, especially during the cold start condition when oil is very thick. The valve is located in the inlet of the oil pressure pump. A solenoid operates the valve position. The ECB controls the solenoid in relation to the APU speed.
4. Interface_________ The Storage and distribution system has interface with:
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the Accessory Cooling System (Ref. 49-52-00),
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the APU Control and Monitoring System (Ref. 49-61-00),
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the Oil Indicating System (Ref. 49-93-00),
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the Low Oil Pressure and the High Oil Temperature Warning System (Ref. 49-94-00).
5. Component Description_____________________
A. Oil Pressure Pump
The main components of the pressure pump are:
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the pump housing,
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the pump rotor,
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the vanes,
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the pressure relief valve.
The oil pressure pump is a vane type unit consisting of a slotted inner
rotor equiped with vanes, a precision ground cam profile and a housing
body.
The main features of the pump are:
-flow rate = 36 l.min (9.5101 USgal.mn) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：A320飞机维护手册 AMM 机载辅助动力 AIRBORNE AUXILIARY POWER 6(78)
