DOC AIRBUS | AMM A320FNO.1 AND NO.2 BEARING SUPPORT MODULE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The No. 1 and No. 2 bearing support module is attached to the fan frame front face with bolts and it supports the fan and booster rotor assemblies.
The bearing support module is made up of the following major parts:
** ON A/C NOT FOR ALL The No. 1 and No. 2 bearing support module is attached to the fan frame front face with bolts and it supports the fan and booster rotor assemblies.
Bearing Support Module No. 1 and No. 2The bearing support module is made up of the following major parts:
- No. 1 bearing support
- No. 1 roller bearing
- No. 2 bearing support
- No. 2 ball bearing
- Oil manifold assembly
- External piping
- Fan shaft
- Forward stationary air/oil seal.
2. System Description
A. No. 1 and No. 2 Bearing Supports
The No. 1 and No. 2 bearing support assembly module is attached to the fan frame hub and consists of a Low Pressure Compressor (LPC) shaft, two bearing supports, two bearings (front roller bearing and rear ball bearing), a load reduction device, a lubrication system, a front sealing system and the speed sensor wheel.
The No. 1 and No. 2 bearing supports are titanium weldment.
The No. 2 bearing support is fitted to the fan frame hub by 37 screws.
The No. 1 bearing support is fitted to the No. 2 bearing support by 20 fuse bolts.
The No. 1 and No. 2 bearing supports function is to provide structural support of the LPC shaft.
The No. 1 and No. 2 bearing support assembly module is attached to the fan frame hub and consists of a Low Pressure Compressor (LPC) shaft, two bearing supports, two bearings (front roller bearing and rear ball bearing), a load reduction device, a lubrication system, a front sealing system and the speed sensor wheel.
The No. 1 and No. 2 bearing supports are titanium weldment.
The No. 2 bearing support is fitted to the fan frame hub by 37 screws.
The No. 1 bearing support is fitted to the No. 2 bearing support by 20 fuse bolts.
The No. 1 and No. 2 bearing supports function is to provide structural support of the LPC shaft.
B. Load Reduction Device
There is a protection device on the No. 1 and No. 2 bearing support assembly to protect the aircraft in case of heavy vibration in case of Foreign Object Damage (FOD) or Fan Blade Out (FBO). The protection device consists of 20 fuse bolts that holds the No. 1 bearing support on the No. 2 bearing support and the fuse pins, locking the load reduction device with fan shaft bushing.
In case of overload, the fuse bolts and/or the fuse pins brakes under radial effort or shaft eccentric rotation, so that the high unbalance loads of the rotor is not transmit to the structure. The engine shuts down, without risk of high energy debris release.
There is a protection device on the No. 1 and No. 2 bearing support assembly to protect the aircraft in case of heavy vibration in case of Foreign Object Damage (FOD) or Fan Blade Out (FBO). The protection device consists of 20 fuse bolts that holds the No. 1 bearing support on the No. 2 bearing support and the fuse pins, locking the load reduction device with fan shaft bushing.
In case of overload, the fuse bolts and/or the fuse pins brakes under radial effort or shaft eccentric rotation, so that the high unbalance loads of the rotor is not transmit to the structure. The engine shuts down, without risk of high energy debris release.
C. No. 1 Roller Bearing
The No. 1 roller bearing is located inside the forward sump, at the front of the No. 1 and No. 2 bearing support assembly.
The function of the No. 1 roller bearing is to provide radial support to the fan and booster module. It is composed of 42 rollers, an outer race housing with squirrel cage shape to allow the radial flexibility needed for the squeeze film and an inner race made of high strength steel.
The squeeze film is a thin oil stream between the No. 1 bearing support housing and the No. 1 bearing support in order to damp the low pressure shaft vibrations.
The housing is attached to the No. 1 bearing support with the eight bolts.
The inner race is attached to the LPC shaft.
The No. 1 roller bearing is located inside the forward sump, at the front of the No. 1 and No. 2 bearing support assembly.
The function of the No. 1 roller bearing is to provide radial support to the fan and booster module. It is composed of 42 rollers, an outer race housing with squirrel cage shape to allow the radial flexibility needed for the squeeze film and an inner race made of high strength steel.
The squeeze film is a thin oil stream between the No. 1 bearing support housing and the No. 1 bearing support in order to damp the low pressure shaft vibrations.
The housing is attached to the No. 1 bearing support with the eight bolts.
The inner race is attached to the LPC shaft.
D. No. 2 Ball Bearing
The No. 2 ball bearing is located inside the forward sump, at the rear of the No. 1 and No. 2 bearing support assembly.
The function of the No. 2 ball bearing is to provide radial and axial support to the fan and booster module rotor. It has 20 balls, an inner race and an outer race. It is made of high strength steel.
The inner race is attached to the load reduction device disk.
The No. 2 ball bearing is located inside the forward sump, at the rear of the No. 1 and No. 2 bearing support assembly.
The function of the No. 2 ball bearing is to provide radial and axial support to the fan and booster module rotor. It has 20 balls, an inner race and an outer race. It is made of high strength steel.
The inner race is attached to the load reduction device disk.
E. LPC Shaft
The LPC shaft is made up of steel alloy.
Its main function is to transmit the Low Pressure Turbine (LPT) torque to the fan and booster module. It attaches both the No. 1 and No. 2 bearings and provides sealing to the sump.
The LPT shaft is attached with 24 oil separator ducts. The oil separator ducts are mounted between the No. 1 and No. 2 bearings. They remove the oil from the engine forward air sump before it is vented to the atmosphere through the Center Vent Tube (CVT).
The LPC shaft is attached to the fan disk with the splines and locked with a slotted nut through a LPC shim (D 48). The LPC shim compensate the assembly tolerances between No. 1 and No. 2 bearing assembly and the LPC spool assembly to avoid the strength at the junction of the two modules through the fan disk.
The slotted nut is locked in rotation by a sealing cover to the LPC shaft, which is locked by a retainer ring.
The LPC shaft is attached to the LPT shaft with a slotted nut through a shim and locked in rotation by a retainer ring.
The LPC shaft is made up of steel alloy.
Its main function is to transmit the Low Pressure Turbine (LPT) torque to the fan and booster module. It attaches both the No. 1 and No. 2 bearings and provides sealing to the sump.
The LPT shaft is attached with 24 oil separator ducts. The oil separator ducts are mounted between the No. 1 and No. 2 bearings. They remove the oil from the engine forward air sump before it is vented to the atmosphere through the Center Vent Tube (CVT).
The LPC shaft is attached to the fan disk with the splines and locked with a slotted nut through a LPC shim (D 48). The LPC shim compensate the assembly tolerances between No. 1 and No. 2 bearing assembly and the LPC spool assembly to avoid the strength at the junction of the two modules through the fan disk.
The slotted nut is locked in rotation by a sealing cover to the LPC shaft, which is locked by a retainer ring.
The LPC shaft is attached to the LPT shaft with a slotted nut through a shim and locked in rotation by a retainer ring.