DOC AIRBUS | AMM A320FFAN AND BOOSTER ASSEMBLY - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
Fan and Booster AssemblyA. Fan and booster assembly
(1) The fan and booster assembly consists of a single-stage fan rotor and a 4-stage axial booster, cantilever-mounted at the rear of the fan disk.
(2) The fan and booster assembly consists of the following sections:
(a) The fan section. It consists of:
- spinner rear and front cones,
- fan disk,
- fan blades.
(b) The booster section. It consists of:
- booster rotor which is a spool with 4 stages of blades,
- booster stator which contains 5 stages of vane assemblies.
2. Description
A. Spinner Front Cone
The spinner front cone is made of composite material. Its design precludes the need for an engine nose anti-icing system. The front cone is bolted to the rear cone.
The spinner front cone is made of composite material. Its design precludes the need for an engine nose anti-icing system. The front cone is bolted to the rear cone.
B. Spinner Rear Cone
The spinner rear cone is made of aluminum alloy. Its rear flange is bolted to the fan disk and is part of the fan blades retention system.
The outer rim of rear flange is provided with tapped holes for trim balance bolts. The front flange provides for attachment of the spinner front cone.
The spinner rear cone is made of aluminum alloy. Its rear flange is bolted to the fan disk and is part of the fan blades retention system.
The outer rim of rear flange is provided with tapped holes for trim balance bolts. The front flange provides for attachment of the spinner front cone.
C. Fan Disk
The fan disk is a titanium alloy forging. Its inner rear flange provides attachment for the fan shaft and its outer rear flange is bolted to the booster rotor. The outer front flange provides attachment for the spinner rear cone. The disk outer rim has 36 recesses designed for fan blade retention.
The fan disk is a titanium alloy forging. Its inner rear flange provides attachment for the fan shaft and its outer rear flange is bolted to the booster rotor. The outer front flange provides attachment for the spinner rear cone. The disk outer rim has 36 recesses designed for fan blade retention.
D. Fan Blades
There are 36 titanium alloy, mid-span shrouded fan blades approximately 23 in. (0.58 m) long. Each of the blades has a dovetail base that engages in disk rim recess.
Blades are individually retained by a spacer that limits radial movement.
A retainer lug, machined at the rear end of each blade root, engages the forward flange of the booster spool and limits the forward and rearward axial movements.
There are 36 titanium alloy, mid-span shrouded fan blades approximately 23 in. (0.58 m) long. Each of the blades has a dovetail base that engages in disk rim recess.
Blades are individually retained by a spacer that limits radial movement.
A retainer lug, machined at the rear end of each blade root, engages the forward flange of the booster spool and limits the forward and rearward axial movements.
E. Booster Rotor
The booster rotor consists of the booster spool and 4 stages of blades.
The booster rotor consists of the booster spool and 4 stages of blades.
(1) The booster spool is forged and machined from titanium and is cantilever-mounted on the rear of the fan disk. The inner front flange, bolted to the fan disk, acts as a stop for the fan blade spacers and blades. The 4-stage spool has circumferential slots that retain the stages 2, 3, 4 and 5 rotor blades, locking lugs and balance weights. Stage 2 has 64 blades, stages 3 and 4 have 70 blades and stage 5 has 68 blades. Rotating air seal serrations are machined between each stage on the outer diameter of spool. A forward rotating air seal, integral with the front web of the booster spool, provides (partial) sealing between the fan rotor stage and the inner shroud of booster stator stage 1 and (partial) pressurization of the engine forward sump.
(2) The booster blades are approximately 3.5 to 4.2 in. (89 to 107 mm) long and serve primarily to supercharge the compressor. Blades are held in the dovetail slots by locking lugs.
F. Booster Vane Assemblies
(1) The stacked vane assemblies are cantilever-mounted on the fan frame front face. The entire assembly is composed of 5 stages of similar design. Each vane assembly consists of:
(a) An outer shroud which, depending on its assembly location, is fitted with one or 2 mounting flanges at its ends. The outer shroud inner face of stages 1, 3, 4 and 5 vanes assemblies is lined with an abradable material facing, respectively, the 2, 3, 4 and 5 rotor blades.
(b) An inner shroud, whose inner face is lined with abradable material facing the seal serrations machined on the booster spool.
(c) Individual vanes of the stage 1 and stage 5 vane assemblies are welded to the outer shroud. Individual vanes of the stages 2, 3 and 4 vane assemblies are bolted to the outer shroud.
(d) Stator vanes are retained on the inner shroud by the abradable material. Stage one vane assembly has 100 vanes, stage 2 vane assembly has 122 vanes, stage 3 vane assembly has 122 vanes, stage 4 vane assembly has 116 vanes and stage 5 vane assembly has 96 vanes.
(2) The outer shroud rear flange of stage 5 vane assembly is bolted to the front face of the fan frame. The inner shroud rear flange is rabbeted to form an interference fit with a corresponding flange on the fan frame.
(3) The outer shroud of booster stage 3 and of stage 5 vane assemblies has an orifice at the 3:30 o'clock position to permit the borescope inspection of the booster mid and rear stages rotor blades (full view) and of the related vane assemblies (partial view only). These borescope orifices are designed SO3 and SO5, respectively in the chapter which follows.