DOC AIRBUS | AMM A320FDISTRIBUTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The function of the oil distribution system is to provide lubrication and cooling to the essential components of the engine.
** ON A/C NOT FOR ALL The function of the oil distribution system is to provide lubrication and cooling to the essential components of the engine.
2. Description
The oil distribution system includes the following components:
** ON A/C NOT FOR ALL The oil distribution system includes the following components:
- an air cooled oil cooler
- a fuel cooled oil cooler
- a pressure oil filter element
- a scavenge oil filter element
- a one-stage pressure pump
- a five-stage scavenge pump
- a deoiler
- a two-position scavenge valve
- a filter bypass valve
- magnetic chip detectors
3. Supply
A. General
The oil leaves the tank through a strainer and is routed into a one-stage pressure pump. It is pumped through a pressure filter to remove any large debris.
The oil is then piped to the air/oil heat exchanger before entering a fuel cooled oil cooler.
After leaving the FCOC, the oil flows to the No. 1, 2 and 3 bearing compartment, to the No. 4 bearing compartment and to the No. 5 bearing compartment, and to both the main and angle gearboxes.
The oil leaves the tank through a strainer and is routed into a one-stage pressure pump. It is pumped through a pressure filter to remove any large debris.
Oil Supply System - SchematicThe oil is then piped to the air/oil heat exchanger before entering a fuel cooled oil cooler.
After leaving the FCOC, the oil flows to the No. 1, 2 and 3 bearing compartment, to the No. 4 bearing compartment and to the No. 5 bearing compartment, and to both the main and angle gearboxes.
B. Description
(1) Protection upstream of the pressure pump
Oil from the tank passes through a coarse stainer and then flows to the pressure pump through a cast passage in the main gearbox.
Oil from the tank passes through a coarse stainer and then flows to the pressure pump through a cast passage in the main gearbox.
(2) Pressure pump
The pressure pump is mounted on the front of the main gearbox. It is a gear type pump with two rotating meshing gears (rotating at 21,8 % of the high rotor speed). The pressure pump housing incorporates the pressure oil filter, a cold-start pressure valve and a pressure-pump- flow triming valve.
The pressure pump is mounted on the front of the main gearbox. It is a gear type pump with two rotating meshing gears (rotating at 21,8 % of the high rotor speed). The pressure pump housing incorporates the pressure oil filter, a cold-start pressure valve and a pressure-pump- flow triming valve.
(3) Pressure circuit
The pressure circuit main components are the pressure pump, the pressure filter, the air cooled oil cooler and the fuel cooled oil cooler.
At engine start-up, the pressure pump draws oil from the tank and pressurizes it. The pressure relief valve bypasses the pressure circuit during cold starts.
The pressure circuit main components are the pressure pump, the pressure filter, the air cooled oil cooler and the fuel cooled oil cooler.
At engine start-up, the pressure pump draws oil from the tank and pressurizes it. The pressure relief valve bypasses the pressure circuit during cold starts.
(4) Pressure pump filter
Oil under pressure is filtered through a 125 micron filter element which protects the pressure nozzle from contamination.
The inlet filtered oil is thus supplied to the critical components.
The pressure filter housing incorporates a pressure priming connection and an anti-drain valve to prevent oil loss during removal.
The filter does not have a bypass. It is a coarser filter than the scavenge filter and can be cleaned.
Oil under pressure is filtered through a 125 micron filter element which protects the pressure nozzle from contamination.
The inlet filtered oil is thus supplied to the critical components.
The pressure filter housing incorporates a pressure priming connection and an anti-drain valve to prevent oil loss during removal.
The filter does not have a bypass. It is a coarser filter than the scavenge filter and can be cleaned.
(5) Distribution system
After leaving the cooling system, the oil is distributed to each area where it is required via a system of pipes.
Except for the No. 3 bearing damper, the pressure of the oil supplied to each location is controlled by a restrictor. There is also a "last chance" strainer at the entry of each compartment to prevent jet blockage by any debris/carbon flakes in the oil.
Oil supply to the main and angle gearboxes is taken from the main oil-feed pipe on the fan casing. The oil enters the main gearbox through a strainer.
The oil supply to the angle gearbox is by an internal passage from the main gearbox.
The oil is transported to the engine core across the fan duct inside the lower bifurcation of the thrust reverser C duct. On reaching the engine core, the oil feed divides to supply the jets in the three bearing compartments.
After leaving the cooling system, the oil is distributed to each area where it is required via a system of pipes.
Except for the No. 3 bearing damper, the pressure of the oil supplied to each location is controlled by a restrictor. There is also a "last chance" strainer at the entry of each compartment to prevent jet blockage by any debris/carbon flakes in the oil.
Oil supply to the main and angle gearboxes is taken from the main oil-feed pipe on the fan casing. The oil enters the main gearbox through a strainer.
The oil supply to the angle gearbox is by an internal passage from the main gearbox.
The oil is transported to the engine core across the fan duct inside the lower bifurcation of the thrust reverser C duct. On reaching the engine core, the oil feed divides to supply the jets in the three bearing compartments.
(6) Anti-syphon system
Before the oil is sent to each of the main compartments some oil may be routed back to the tank through the anti-syphon vent.
This vent, located at the exit of the FCOC, prevents the syphoning of oil from the tank to the main gearbox when the engine is static.
Before the oil is sent to each of the main compartments some oil may be routed back to the tank through the anti-syphon vent.
This vent, located at the exit of the FCOC, prevents the syphoning of oil from the tank to the main gearbox when the engine is static.
(7) Oil system indication
(a) Oil pressure
The oil pressure transmitter enables the oil pressure within the system to be monitored. This pressure is indicated by the ECAM system.
The oil pressure transmitter enables the oil pressure within the system to be monitored. This pressure is indicated by the ECAM system.
(b) Oil temperature
The oil temperature is related to the engine speed, the fuel temperature and the oil flow rate. Max oil supply temperature:
The oil temperature is related to the engine speed, the fuel temperature and the oil flow rate. Max oil supply temperature:
- steady state : 155 deg.C.
- transient : 165 deg.C (15 minutes).
(c) A low-pressure switch is installed in order to warn the crew when the decreasing pressure reaches 60 psid.
(a) General
The filtered oil flows through the air cooled oil cooler before being cooled again through the fuel cooled oil cooler.
The filtered oil flows through the air cooled oil cooler before being cooled again through the fuel cooled oil cooler.
(b) Description
The ACOC is mounted on the engine fan case.
The ACOC has a plate and corrugated fin construction and consists of a core header, a flange and a duct.
The core, header, flange and duct are made of aluminium alloys and are welded to each other to form the unit.
The core is composed of 11 layers of air-side fins and 10 layers of oil-side fins.
The ACOC is mounted on the engine fan case.
The ACOC has a plate and corrugated fin construction and consists of a core header, a flange and a duct.
The core, header, flange and duct are made of aluminium alloys and are welded to each other to form the unit.
The core is composed of 11 layers of air-side fins and 10 layers of oil-side fins.
(c) Operation
The ACOC removes heat from the engine lubricating oil by means of cooling fan air and maintains the oil temperature within the specified range.
The flow configuration is double-pass flow.
The ACOC removes heat from the engine lubricating oil by means of cooling fan air and maintains the oil temperature within the specified range.
The flow configuration is double-pass flow.
(9) Fuel cooled oil cooler(FCOC)
The oil passed through the ACOC flows through the fuel cooled oil cooler (FCOC) before it is sent to the bearing compartments and both the angle and main gearboxes.
The oil passed through the ACOC flows through the fuel cooled oil cooler (FCOC) before it is sent to the bearing compartments and both the angle and main gearboxes.
(a) General
The FCOC cools the oil by using fuel as a cooling medium.
The FCOC is installed on the fan casing.
The FCOC cools the oil by using fuel as a cooling medium.
The FCOC is installed on the fan casing.
(b) Description
1 The FCOC consists of a housing containing a removable core, a header and a fuel filter cap. The housing is made from a one-piece casting.
2 The core is composed of more than 700 tubes through which fuel passes. These tubes are vacuum-brazed hermetically to end plates. 13 baffle plates, which are also vacuum-brazed to the tubes, direct the oil flow around the tubes.
3 The FCOC has two bypass valves. One is an oil-pressure-relief bypass valve for the core and the other is a fuel-filter bypass valve.
4 The housing provides the mounting facilities for a fuel diverter valve, oil and fuel temperature sensors and a fuel differential pressure switch.
5 The anti-syphon hole is located between the oil inlet and outlet ports to prevent to the oil from emptying after engine shutdown.
(c) Operation
1 The FCOC dissipates the engine heat by exchanging heat between the engine lubricating oil and the low-pressure fuel in the system.
2 The FCOC warms the low-temperature fuel to the de-icing level.
3 The oil-pressure-relief bypass valve diverts the excessive oil pressure during the engine cold start.
4 The fuel-filter bypass valve ensures fuel flow in the event of fuel filter clogging.
4. Scavenge
A. General
The oil (which has lubricated the engine bearings and the angle and main gearbox) is piped either directly or through the deoiler to the scavenge pumps.
The line to each scavenge pump incorporates a strainer and a magnetic chip detector.
The chip detector for the No. 4 bearing compartment is in the deoiler scavenge outlet.
The combined flow from all the scavenge pump outlets is returned to the oil tank via a cyclone type deaerator mounted within the tank.
The oil (which has lubricated the engine bearings and the angle and main gearbox) is piped either directly or through the deoiler to the scavenge pumps.
The line to each scavenge pump incorporates a strainer and a magnetic chip detector.
The chip detector for the No. 4 bearing compartment is in the deoiler scavenge outlet.
The combined flow from all the scavenge pump outlets is returned to the oil tank via a cyclone type deaerator mounted within the tank.
B. Description
The scavenge circuit main components are:
The scavenge circuit main components are:
- five scavenge filters with chip detectors,
- five scavenge pumps,
- one common scavenge filter.
- A 2-positions scavenge valve.
(1) Protection upstream of the scavenge pumps
The oil passes through the chip detectors and the scavenge filters (strainers) and then to the scavenge pumps.
The oil passes through the chip detectors and the scavenge filters (strainers) and then to the scavenge pumps.
(2) Scavenge pump
The scavenge pump is a five-stage pump on the rear left side of the geabox. Four stages of the scavenge pump are two-gear displacement pumps which operate at 21.8 percent of the high rotor-shaft speed.
The stage used for the two main gearbox scavenge lines consists of three meshing gears producing two inlets and outlets on opposite sides. It operates at the same speed as the other stages.
The scavenge pump is a five-stage pump on the rear left side of the geabox. Four stages of the scavenge pump are two-gear displacement pumps which operate at 21.8 percent of the high rotor-shaft speed.
The stage used for the two main gearbox scavenge lines consists of three meshing gears producing two inlets and outlets on opposite sides. It operates at the same speed as the other stages.
(3) Scavenge filter
The flows from the 5 scavenge pumps are mixed together at the scavenge common filter inlet.
This filter assembly consists of the following:
The flows from the 5 scavenge pumps are mixed together at the scavenge common filter inlet.
This filter assembly consists of the following:
(a) One 30 micron filter
(b) One bypass valve which opens if the filter clogs (set at 20 psi).
(4) Two-position scavenge valve
(a) Oil and vent air from the No. 4 bearing compartment is scavenged through a common line. This dual-purpose line is piped through the two-position scavenge valve (and then continues to the deoiler).
The two-position scavenge valve opens to the maximum flow area at low power to maximum scavenging. At high power it closes to the minimum area to maintain the seal pressure differentials and reduce overboard loss of vent air.
The two-position scavenge valve opens to the maximum flow area at low power to maximum scavenging. At high power it closes to the minimum area to maintain the seal pressure differentials and reduce overboard loss of vent air.
(b) Operation
The valve operates in the following manner. There are two basic operating positions, low power and high power. In the low-power position, where the compressor 10th stage pressure (P10) is less than 150 PSI, the valve is held spring loaded in the fully open position. The bearing compartment scavenge flow passes through the valve, restricted only by the porting in the valve seat.
As the engine power increases, the P10 pressure rises. When this pressure exceeds 150 psi, the valve moves away from the max flow stop. This is due to the pressure acting on the differential areas of the valve and overcoming the spring load. The valve moves towards the min flow or high power setting. As the valve moves towards the peripheral ports in the seat, totally closing these ports, the flow through the valve is now restricted to one central port in the valve seat. Full travel is achieved at P10 pressure of approximately 210 psi.
As the valve moves away from the max flow stop, the influence of the magnets on the reed switch decreases and the reed switch opens. The circuit is broken, indicating that the valve has moved.
As the engine power decreases, the spring load overcomes the decreasing P10 pressure. The valve moves towards the max flow or low power position, uncovering the ports in the valve seat and restoring maximum flow through the valve. As the valve approaches the maximum flow stop, the influence of the magnets on the reed switch increases.
The reed switch closes, completing the circuit and indicating the valve position.
The valve operates in the following manner. There are two basic operating positions, low power and high power. In the low-power position, where the compressor 10th stage pressure (P10) is less than 150 PSI, the valve is held spring loaded in the fully open position. The bearing compartment scavenge flow passes through the valve, restricted only by the porting in the valve seat.
As the engine power increases, the P10 pressure rises. When this pressure exceeds 150 psi, the valve moves away from the max flow stop. This is due to the pressure acting on the differential areas of the valve and overcoming the spring load. The valve moves towards the min flow or high power setting. As the valve moves towards the peripheral ports in the seat, totally closing these ports, the flow through the valve is now restricted to one central port in the valve seat. Full travel is achieved at P10 pressure of approximately 210 psi.
As the valve moves away from the max flow stop, the influence of the magnets on the reed switch decreases and the reed switch opens. The circuit is broken, indicating that the valve has moved.
As the engine power decreases, the spring load overcomes the decreasing P10 pressure. The valve moves towards the max flow or low power position, uncovering the ports in the valve seat and restoring maximum flow through the valve. As the valve approaches the maximum flow stop, the influence of the magnets on the reed switch increases.
The reed switch closes, completing the circuit and indicating the valve position.