DOC AIRBUS | AMM A320FENGINE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The engine is a dual-rotor, variable stator, high bypass ratio turbo fan power plant.
The 9 stage high pressure compressor is driven by 1 stage high pressure turbine, and the integrated front fan and booster is driven by 4 stage low pressure turbine. An annular combustor converts fuel and compressor discharge air into energy to provide engine thrust part through primary exhaust and to drive the turbines. The accessory drive system extracts energy from the high pressure rotor to drive the engine accessories and the engine mounted aircraft accessories. Reverse thrust for braking the aircraft after landing is supplied by an integrated system which acts on the fan discharge airflow (Ref. 78-00-00).
** ON A/C NOT FOR ALL The engine is a dual-rotor, variable stator, high bypass ratio turbo fan power plant.
Engine-LHThe 9 stage high pressure compressor is driven by 1 stage high pressure turbine, and the integrated front fan and booster is driven by 4 stage low pressure turbine. An annular combustor converts fuel and compressor discharge air into energy to provide engine thrust part through primary exhaust and to drive the turbines. The accessory drive system extracts energy from the high pressure rotor to drive the engine accessories and the engine mounted aircraft accessories. Reverse thrust for braking the aircraft after landing is supplied by an integrated system which acts on the fan discharge airflow (Ref. 78-00-00).
2. Engine Modules
The principal modules of the engine are fan and booster, high pressure compressor, combustor chamber, high pressure turbine, low pressure turbine and accessory drive gearbox. Detailed descriptions of the components of each section are given in corresponding sections of this document.
The description of each engine module is as follows:
The principal modules of the engine are fan and booster, high pressure compressor, combustor chamber, high pressure turbine, low pressure turbine and accessory drive gearbox. Detailed descriptions of the components of each section are given in corresponding sections of this document.
The description of each engine module is as follows:
A. Fan/Booster Rotor
The fan rotor consists of one full diameter booster for the secondary flow single stage fan and a smaller 3 stage booster for the core engine flow.
The fan and the booster are mounted on a common internal concentric shaft driven by the fan pressure turbine. Two bearings support the fan assembly in the frame.
The fan rotor consists of one full diameter booster for the secondary flow single stage fan and a smaller 3 stage booster for the core engine flow.
The fan and the booster are mounted on a common internal concentric shaft driven by the fan pressure turbine. Two bearings support the fan assembly in the frame.
B. Fan/Booster Stator
Fixed stator vanes are provided for both, the fan and booster rotor. The fan casing, in which the stator is mounted has provision for blade containment forward of and in the plan of the fan rotor. The casing is supported by the fan frame and supports the accessory drive gearbox.
Fixed stator vanes are provided for both, the fan and booster rotor. The fan casing, in which the stator is mounted has provision for blade containment forward of and in the plan of the fan rotor. The casing is supported by the fan frame and supports the accessory drive gearbox.
C. Fan Frame
The fan frame is one of the major structural and aerodynamic components of the engine. Aerodynamically the fan frame forms the inner and outer flow passage of the fan airstream as well as the core airstream.
Structurally, it carries air intake cowl loads, supports the fan casing, the two fan bearings and the core engine forward bearing; it contains the forward engine mount, it houses the accessory drive power take off gearbox and radial drive shaft; it contains the variable bypass valves between the booster and high pressure compressor; it supports the transfer and accessory gearboxes; and provides the mounting surfaces for fan-stream acoustic panels.
The fan frame also serves as the forward support for the compressor.
The fan frame is one of the major structural and aerodynamic components of the engine. Aerodynamically the fan frame forms the inner and outer flow passage of the fan airstream as well as the core airstream.
Structurally, it carries air intake cowl loads, supports the fan casing, the two fan bearings and the core engine forward bearing; it contains the forward engine mount, it houses the accessory drive power take off gearbox and radial drive shaft; it contains the variable bypass valves between the booster and high pressure compressor; it supports the transfer and accessory gearboxes; and provides the mounting surfaces for fan-stream acoustic panels.
The fan frame also serves as the forward support for the compressor.
D. Compressor Rotor
The compressor is a nine stage axial flow assembly. The rotor consists of the stage 1 and 2 discs which form a spool, a separately attached stage 3 disc and a spool containing stage 4 - 9 discs. Stage 1, 2 and 3 have axial dovetail slots and stage 4 - 9 blades are retained in circumferential slots. All blades are individually repleacable without spool disassembly.
The compressor is a nine stage axial flow assembly. The rotor consists of the stage 1 and 2 discs which form a spool, a separately attached stage 3 disc and a spool containing stage 4 - 9 discs. Stage 1, 2 and 3 have axial dovetail slots and stage 4 - 9 blades are retained in circumferential slots. All blades are individually repleacable without spool disassembly.
E. Compressor Stator
All 9 stages of the compressor stator are shrouded. The Inlet Guide Vanes (IGV) and the first 3 stages of the compressor are variable. The casing is composed of two semi cylindrical halves, permitting a quick access to the core engine compressor.
All 9 stages of the compressor stator are shrouded. The Inlet Guide Vanes (IGV) and the first 3 stages of the compressor are variable. The casing is composed of two semi cylindrical halves, permitting a quick access to the core engine compressor.
F. Combustor
A step diffuser is incorporated upstream of the combustor for reduction of the combustor sensitivity to the compressor velocity profile. The combustor can be replaced without disturbing the fuel nozzles. The combustor casing provides structural support for the combustor, the compressor Outlet Guide Vanes (OGV) the High Pressure (HP) stator and shrouds, and the seals for Compressor Discharge Pressure (CDP).
A step diffuser is incorporated upstream of the combustor for reduction of the combustor sensitivity to the compressor velocity profile. The combustor can be replaced without disturbing the fuel nozzles. The combustor casing provides structural support for the combustor, the compressor Outlet Guide Vanes (OGV) the High Pressure (HP) stator and shrouds, and the seals for Compressor Discharge Pressure (CDP).
G. High Pressure Turbine
The High Pressure Turbine (HPT) is an air cooled single stage high energy turbine. Rotor blades are individually replaceable without the need for rotor disassembly or rebalancing.
The High Pressure Turbine (HPT) is an air cooled single stage high energy turbine. Rotor blades are individually replaceable without the need for rotor disassembly or rebalancing.
H. Low Pressure Turbine
The Low Pressure Turbine (LPT) consists of 4 and half stages of blades and vanes. The first stage nozzle vane is cooled and provides cooling air for the high pressure and low pressure turbine discs.
The LPT drives the fan rotor through the inner concentric shaft and is aerodynamically coupled to the high pressure system. The LPT casing is a 360 degrees design to provide structural continuity.
The Low Pressure Turbine (LPT) consists of 4 and half stages of blades and vanes. The first stage nozzle vane is cooled and provides cooling air for the high pressure and low pressure turbine discs.
The LPT drives the fan rotor through the inner concentric shaft and is aerodynamically coupled to the high pressure system. The LPT casing is a 360 degrees design to provide structural continuity.
I. Turbine Frame
The turbine frame is located aft of the LPT. It contains the aft LPT bearing, and supports the primary exhaust system. It contains the engine rear mount fitting.
The turbine frame is located aft of the LPT. It contains the aft LPT bearing, and supports the primary exhaust system. It contains the engine rear mount fitting.
J. Accessories and Accessory Drives
Engine and aircraft accessories are mounted on the accessory gearbox which is located on the outside of the lower part of the casing and driven through a radial shaft at 6 o'clock position. Power for the engine and aircraft accessories is extracted from the HPC rotor shaft through an inlet gearbox and the radial drive shaft. Quick Attach-Detach (QAD) accessory mounting flanges are provided for the engine accessories.
Engine and aircraft accessories are mounted on the accessory gearbox which is located on the outside of the lower part of the casing and driven through a radial shaft at 6 o'clock position. Power for the engine and aircraft accessories is extracted from the HPC rotor shaft through an inlet gearbox and the radial drive shaft. Quick Attach-Detach (QAD) accessory mounting flanges are provided for the engine accessories.
3. Bearings and Seals
A. Bearings
The engine rotors are supported by bearings installed in the sump cavities provided by the two frames. The forward sump is in the fan frame and is the location of bearings No. 1, No. 2 (fan/booster shaft) and No. 3 (HP shaft forward part).
The aft sump is in the turbine rear frame where are bearings No. 4 (HP shaft aft part) and No. 5 (LP shaft aft part).
The engine rotors are supported by bearings installed in the sump cavities provided by the two frames. The forward sump is in the fan frame and is the location of bearings No. 1, No. 2 (fan/booster shaft) and No. 3 (HP shaft forward part).
The aft sump is in the turbine rear frame where are bearings No. 4 (HP shaft aft part) and No. 5 (LP shaft aft part).
B. Oil Distribution
The bearings must be lubricated and oil is distributed to these components by nozzles. However, as the oil must be retained within the engine, seals of various types are provided to confine the oil and direct its recirculation.
The bearings must be lubricated and oil is distributed to these components by nozzles. However, as the oil must be retained within the engine, seals of various types are provided to confine the oil and direct its recirculation.
C. Seals Arrangement
The arrangement of oil and air seals, the provisions for oil supply, oil scavenge, seal pressurization, sump vent subsystems constitute a dry sump system.
Engine sumps are vented to ambient pressure through the center vent tube which is contained in the LP shaft.
The arrangement of oil and air seals, the provisions for oil supply, oil scavenge, seal pressurization, sump vent subsystems constitute a dry sump system.
Engine sumps are vented to ambient pressure through the center vent tube which is contained in the LP shaft.
D. Bearing Functions
Bearings provide reduced rolling friction, support the rotors axially and radially within the engine structure, and position the rotors relative to the stators. The bearing must control the forces of gravity weight, aerodynamic loads of pumping and turbine driving, and gyroscopic loads due to aircraft maneuvers.
Bearings provide reduced rolling friction, support the rotors axially and radially within the engine structure, and position the rotors relative to the stators. The bearing must control the forces of gravity weight, aerodynamic loads of pumping and turbine driving, and gyroscopic loads due to aircraft maneuvers.