DOC AIRBUS | AMM A320FENGINE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The PW1130G engine is an axial-flow turbofan with a twin-spool low and high pressure rotor system. The engine is electronically controlled by the Full Authority Digital Engine Control (FADEC). The fan in the low pressure rotor system operates at a lower speed than the rest of the low pressure rotor system. The torque supplied to the fan is through a driveshaft, but turning at a lower speed through a Fan Drive Gearbox (FDG). The FDG is a planetary gear system in a star configuration. Also, the fan case includes the forward mount location for the nacelle cowling hardware.
Downstream from the fan, there are two isolated airstreams. The primary airstream moves through the engine core to make high temperature, pressurized gasses that supply a propulsive force to the aircraft. The secondary (or outer) airstream is mechanically compressed by the fan on entry to the engine and is exhausted through the Structural Guide Vanes (SGV) to make the thrust.
The primary airstream goes into the compressor section which includes a three stage Low Pressure Compressor (LPC) and an eight stage High Pressure Compressor (HPC). The LPC and the HPC compress the air before it moves into the diffuser and annular combustor.
Expanded gas pressure from the combustor is sent through vanes to the turbine section to turn the two stage High Pressure Turbine (HPT). The torque made by the HPT turns the HPC which share a high pressure rotor. The remaining pressurized gas moves to the three stage Low Pressure Turbine (LPT). The torque made by the LPT turns the LPC and the FDG which share a low pressure rotor. The low pressure rotor connects the fan rotor through the FDG.
The primary engine structure is made from four frames: the Fan Intermediate Case (FIC), the Compressor Intermediate Case (CIC), the Turbine Intermediate Case (TIC) and the Turbine Exhaust Case (TEC). The engine cases form the primary structure of the engine when bolted together and function as a support for all of the inner parts through struts and bearings. The engine has five bearing compartments and seven bearings.
The engine includes a Main Gear Box (MGB) installed on the core, that supplies torque to turn the aircraft accessories. There is also an angle gearbox which transmits torque from the high pressure rotor to the main gearbox and accessories. During engine start, the torque is sent in the opposite direction.
** ON A/C NOT FOR ALL The PW1130G engine is an axial-flow turbofan with a twin-spool low and high pressure rotor system. The engine is electronically controlled by the Full Authority Digital Engine Control (FADEC). The fan in the low pressure rotor system operates at a lower speed than the rest of the low pressure rotor system. The torque supplied to the fan is through a driveshaft, but turning at a lower speed through a Fan Drive Gearbox (FDG). The FDG is a planetary gear system in a star configuration. Also, the fan case includes the forward mount location for the nacelle cowling hardware.
Engine - GeneralDownstream from the fan, there are two isolated airstreams. The primary airstream moves through the engine core to make high temperature, pressurized gasses that supply a propulsive force to the aircraft. The secondary (or outer) airstream is mechanically compressed by the fan on entry to the engine and is exhausted through the Structural Guide Vanes (SGV) to make the thrust.
The primary airstream goes into the compressor section which includes a three stage Low Pressure Compressor (LPC) and an eight stage High Pressure Compressor (HPC). The LPC and the HPC compress the air before it moves into the diffuser and annular combustor.
Expanded gas pressure from the combustor is sent through vanes to the turbine section to turn the two stage High Pressure Turbine (HPT). The torque made by the HPT turns the HPC which share a high pressure rotor. The remaining pressurized gas moves to the three stage Low Pressure Turbine (LPT). The torque made by the LPT turns the LPC and the FDG which share a low pressure rotor. The low pressure rotor connects the fan rotor through the FDG.
The primary engine structure is made from four frames: the Fan Intermediate Case (FIC), the Compressor Intermediate Case (CIC), the Turbine Intermediate Case (TIC) and the Turbine Exhaust Case (TEC). The engine cases form the primary structure of the engine when bolted together and function as a support for all of the inner parts through struts and bearings. The engine has five bearing compartments and seven bearings.
The engine includes a Main Gear Box (MGB) installed on the core, that supplies torque to turn the aircraft accessories. There is also an angle gearbox which transmits torque from the high pressure rotor to the main gearbox and accessories. During engine start, the torque is sent in the opposite direction.
2. Description
A. Engine modules:
- Reduction gear and shaft section (Ref. AMM D/O 72-10-00-00)
- Air inlet section (Ref. AMM D/O 72-20-00-00)
- Compressor section (Ref. AMM D/O 72-30-00-00)
- Combustion section (Ref. AMM D/O 72-40-00-00)
- Turbine section (Ref. AMM D/O 72-50-00-00)
- Accessory drives (Ref. AMM D/O 72-60-00-00).
- The fan rotor module has a low pressure ratio fan rotor located at the forward end of the engine. The fan rotor includes 20 fan blades with fan blade fairings located between each fan blade root platform to keep a smooth airflow between the blades. The fan rotor is supplied torque, but at a decreased speed, through the FDG connected to the fan rotor by a gearbox front shaft. The function of the fan rotor is to supply the primary source of engine thrust through the initial compression of ambient air. Compressed air that leaves the fan rotor is divided by the FIC and flows through both the fan nozzle (secondary flow) and the LPC to the core of the engine (primary flow).
- The fan rotor is housed in the fan case assembly. The function of the fan case assembly is to contain and make the fan airflow straight, to give protection and containment for a fan blade failure and to supply structural attachment points between the inlet cowl and the core engine. The inner case has acoustic liners to decrease noise at the front and rear of the case, a rubstrip liner for the fan blades and a liner which supplies protection from ice. At the rear of the fan case assembly is an aluminum support ring which has a ’V’ groove that supplies alignment and functions as a support for the thrust reverser doors. The fan case assembly also includes 48 SGVs. They are located at the rear of the fan case and extend diagonally forward to the FIC to function as a support for the fan case and make the bypass air straight.
- For more information on the fan rotor and fan case (Ref. AMM D/O 72-11-00-00) and (Ref. AMM D/O 72-21-00-00).
- The FDG is a planetary gear unit in a star arrangement that decreases the fan shaft speed from the LPT shaft. The FDG gets the torque from the LPT and uses it to turn a sun gear. This sun gear then turns five planet gears against an outer ring gear set which is connected to the gearbox front shaft. The gearbox front shaft is connected to the fan rotor.
- There are journal bearings at each planet gear position. With these bearings, the cylindrical surfaces of the gear inner diameters turn against their mating pivots. The gears are housed in a carrier which is attached at the rear to the FIC by inner and outer assemblies. Pins through the inner carrier function as a radial support.
- The journal bearings, FDG gears and inner pins are lubricated with pressure oil from an oil manifold at the rear of the FDG. Oil from the journal oil shuttle valve goes through the oil manifold, journal bearing oil supply tubes and journal bearing oil filters to the journal bearings. The Variable Oil Reduction Valve (VORV) controls the flow of oil through the VORV oil manifold to the gear oil filters and nozzles and then to the FDG gears and the inner pins.
- A windmill pump, which turns at fan speed, is located in the compartment. The gravity valve in the front of the assembly changes the flow of oil during flight conditions. During normal engine operation (when main oil pump pressure supplies the FDG bearings sufficiently), the gravity valve lets oil from the compartment auxiliary reservoir be sent by the windmill pump to the main oil tank through the journal oil shuttle valve. During windmill conditions, the gravity valve lets oil from the sump go through the windmill pump to the journal bearings through the journal oil shuttle valve. During zero and negative G conditions, the gravity valve lets oil from the auxiliary reservoir go through the windmill pump to the journal bearings through the journal oil shuttle valve.
- For more information on the FDG (Ref. AMM D/O 72-15-00-00).
- The FIC is made from titanium and located between the fan case and the LPC. It gives an aerodynamic flow path between the fan rotor and the LPC and also functions as a support between the fan case and the engine core through its connection to the FEGVs. The FIC houses the FDG and the No. 2 bearing. The No. 2 bearing functions as a support axially and radially for the LPC and the fan input coupling which supply torque to the FDG. There are eight hollow struts that are supports and supply a passage through the airflow for oil, air and electrical components.
- For more information on the FIC (Ref. AMM D/O 72-22-00-00).
- The LPC is located aft of the FIC. The three stage LPC initially compresses the fan air on the path to the core of the engine (primary flow). The LPC rotor is supplied torque by the LPT.
- The LPC rotor hub is attached to the LPT shaft which connects the LPC to the fan rotor through the fan input coupling and FDG. The FDG lets the LPC turn at a higher speed than the fan rotor for increased efficiency.
- At the inlet to the LPC, there is one stage of Variable Inlet Guide Vanes (VIGV). The remaining part of the LPC has three Integrally Bladed Rotors (IBR) and two stator stages. To increase the range of operation and to reject dirt from the LPC airstream, there is an annular LPC (Stage 2.5) bleed valve at the rear of the LPC.
- For more information on the LPC (Ref. AMM D/O 72-31-00-00).
- The CIC functions as the support between the LPC and the HPC. The case includes nine aerodynamic struts, two primary engine mounts and a redundant engine mount. The CIC also transmits the thrust loads from the engine at two thrust mounts. The module includes a fire containment ring that supplies protection for the LPC structure from the core nacelle fire zone and functions as a support for the thrust reverser inner cowl.
- The CIC also houses the No. 3 bearing compartment. The No. 3 bearing functions as a radial and axial support at the front of the HPC. A pressurized layer of oil supplied to the circumference of the No. 3 bearing assembly support absorbs rotor radial movement and decreases vibration. The compartment includes carbon face seals at the front and the rear, and labyrinth seals to control the flow of oil and air in the compartment. Forward of the No. 3 bearing is the No. 3 bearing bevel gear which engages a gearbox drive bevel gear to supply torque between the HPC and the angle gearbox.
- For more information on the CIC (Ref. AMM D/O 72-34-00-00).
- The HPC increases the speed, pressure and temperature of the primary gaspath air and supplies this air to the diffuser and combustor. There are eight stages to the HPC. The VIGVs (part of the CIC) and the first three stages of vanes in the HPC are variable. The 4th to 7th stage stators are fixed (cantilevered) and seal against the adjacent rotor abrasive. Knife edge seals on the rotors seal against the stator vanes. The rotor stages are held together with a rotor shaft. This shaft connects the front hub with the rear hub and extends rearward to the HPT. The HPC is held radially and axially at the front by the No. 3 bearing. It is held radially at the rear by the No. 4 bearing. The outer case wall is made of the front case set between the CIC and the diffuser case. The outer air seals make the inner case wall. The HPT supplies torque to the HPC. A rotor nut at the rear hub holds the HPC rotor assembly together. The compressor supplies air to the customer bleed system and other engine systems. The front six stages of the rotor are decreased in temperature by bleed air. The rear two stages of the compressor are compartmentalized from the front by a ring on the rotor shaft. The rear rotor compartment temperature is controlled by airflow slots in the spacer and the rotor tube assembly.
- For more information on the HPC (Ref. AMM D/O 72-35-00-00).
- The diffuser case, combustion chamber and turbine nozzle supply the hot exhaust gasses of internal combustion to the turbine modules. The diffuser also functions as a structural support for the HPC and HPT cases.
- Compressed air flows from the exit of the HPC into the diffuser and combustor section. During entry, the airflow is made straight while the contour of the inner diffuser case lets the air expand before it moves to the combustion chamber. Metered fuel is supplied to the combustion chamber through 18 fuel nozzles and the fuel and air mixture is burned inside the combustion chamber. The HPT 1st stage vanes point the high temperature, high velocity gasses, out of the combustion chamber to supply the turbines and make thrust at the exhaust nozzle.
- For more information on the diffuser and combustor (Ref. AMM D/O 72-41-00-00) and (Ref. AMM D/O 72-42-00-00).
- The HPT module changes some of the high temperature, high velocity gas energy into torque. The 1st stage turbine vanes point the gasses out of the combustion chamber at an efficient angle which turns the HPT.
- The HPT module is a rotor system with two stages and 44 blades in each of the rotors. The rotor system is housed by the HPT case which contains the 26 Blade Outer Air Seals (BOAS) for each stage. Cool air flows through holes in the BOAS and into the gaspath. The HPT case is the containment structure for the turbine rotors and functions as structural support to the diffuser case and also houses the TIC.
- For more information on the HPT (Ref. AMM D/O 72-51-00-00).
- The TIC is housed in the HPT case and is made of an inner case, a turbine stator assembly and the No. 4 bearing assembly. The TIC is between the HPT and the LPT.
- The TIC assembly uses eight TIC rods as supports to connect the inner case to the HPT case through the hollow vanes in the TIC stator assembly. The TIC rods function as supports for the No. 4 bearing compartment. The TIC stator assembly has 16 hollow airfoils that turn the gaspath airflow to align with the LPT rotor. Pressure, scavenge and drain oil tubes from the No. 4 bearing compartment go through the hollow vanes and also a buffer air tube goes through into the No. 4 bearing compartment.
- For more information on the TIC (Ref. AMM D/O 72-52-00-00).
- The LPT is made of a three stage rotor, a turbine case assembly, two stator vane stages and an LPT driveshaft. The LPT provides the rotational force for the LPC and FDG. The energy from the hot combustion gasses is changed into torque by the LPT blade and rotor assemblies. There are 84 1st stage, 86 2nd stage solid nickel alloy shrouded blades and 78 3rd stage solid titanium aluminide alloy shrouded blades that have a fir tree to attach to each disk.
- For more information on the LPT (Ref. AMM D/O 72-53-00-00).
- The TEC assembly is a main structural part of the engine and attaches to the rear flange of the LPT. The TEC assembly functions as a support for the No. 5 and No. 6 bearing assemblies and has connection points for the aft engine mounts. There are bosses in the outer wall of the TEC for four Exhaust Gas Temperature (EGT) probes that extend into the gaspath.
- The TEC is a one-piece case welded structure with ten airfoil−contour vanes (struts) which hold two bearing housings at its inner flanges. The No. 6 bearing is an oil−damped type in which a layer of pressurized oil around the bearing outer race absorbs engine vibration. The scavenge oil tube and bearing pressure oil tube go through the bottom struts of the TEC to supply oil to the No. 5 and No. 6 bearings.
- For more information on the TEC (Ref. AMM D/O 72-54-00-00).
- The function of the MGB is to supply torque to the oil, fuel and hydraulic system components connected to the main gearbox. The main gearbox is supplied torque by the HPC and AGB.
- The MGB housing is installed below the HPC and contains ball and roller bearings, carbon seals and gear shafts which connect the different system components. The deoiler is an internal component of the main gearbox and removes oil from lubrication breather mixtures. There is an opening to turn the N2 system by hand so that the HPC and HPT rotors can be inspected. In the MGB, oil lubricates the ball and roller bearings and the gearshafts. The oil is supplied to the MGB housing from an external oil supply tube. Scavenge oil that exits the MGB is sent to the oil tank by the lubrication and scavenge pump. As much as possible, the MGB uses internal casting openings to supply oil to the different bearings and components and to supply fuel to different components. This makes many external tubes not necessary and decreases the risk of leakage.
- For more information on the MGB (Ref. AMM D/O 72-61-00-00).
- The AGB connects the CIC to the MGB through the layshaft of the AGB. The AGB housing is a support for the ball and roller bearings and gear shafts and contains a borescope opening and oil drain plugs.
- The AGB is connected to the CIC with four bolts to the CIC flange. During engine operation the torque from the HPC shaft is transmitted to the gearbox drive shaft and into the AGB. The AGB then transmits the torque with gear shafts through the layshaft to the MGB. Roller and ball bearings hold each gear shaft in the axial and radial positions. In the AGB, oil lubricates the ball and roller bearings and gearshafts. The oil is supplied from external oil supply tubes. Scavenge oil that exits the AGB housing is sent to the oil tank.
- For more information on the AGB (Ref. AMM D/O 72-62-00-00).