DOC AIRBUS | AMM A320FLPT ROTOR AND STATOR MODULE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The Low Pressure turbine (LPT) is a seven stage axial flow turbine. The LPT rotor and stator module is located between the LPT stage 1 nozzle module (Ref. AMM D/O 72-56-00-00), the LPT shaft module and the Turbine Rear Frame (TRF) module (Ref. AMM D/O 72-59-00-00).
The major parts of the LPT rotor and stator module are:
** ON A/C NOT FOR ALL The Low Pressure turbine (LPT) is a seven stage axial flow turbine. The LPT rotor and stator module is located between the LPT stage 1 nozzle module (Ref. AMM D/O 72-56-00-00), the LPT shaft module and the Turbine Rear Frame (TRF) module (Ref. AMM D/O 72-59-00-00).
The major parts of the LPT rotor and stator module are:
- LPT stator assembly
- LPT rotor assembly
- No. 5 roller bearing.
2. System Description
A. LPT Stator
The LPT stator consists of six stages nozzles (stage 2 to 7 and stage 1 are covered in LPT stage 1 nozzle module (Ref. AMM D/O 72-56-00-00), six stages air seals (stage 1 to 6 and stage 7 are part of the TRF module) (Ref. AMM D/O 72-59-00-00) and LPT case with the cooling tubes and manifolds assembly.
The LPT stator consists of six stages nozzles (stage 2 to 7 and stage 1 are covered in LPT stage 1 nozzle module (Ref. AMM D/O 72-56-00-00), six stages air seals (stage 1 to 6 and stage 7 are part of the TRF module) (Ref. AMM D/O 72-59-00-00) and LPT case with the cooling tubes and manifolds assembly.
(1) Nozzle
The function of the nozzle is to convert the velocity increase into the pressure rise. The nozzle is attached to the LPT case with the retainer ring. The stages 2 to 7 nozzles are made of nickel based alloy. The shim is placed between the nozzle and the LPT case to prevent the wear due to nozzle fretting on the LPT case.
The function of the nozzle is to convert the velocity increase into the pressure rise. The nozzle is attached to the LPT case with the retainer ring. The stages 2 to 7 nozzles are made of nickel based alloy. The shim is placed between the nozzle and the LPT case to prevent the wear due to nozzle fretting on the LPT case.
(2) Shroud
The shroud supports an abradable for the inter-stage sealing and provide the retention for the blades. It is attached in axial position with a clamp. The shroud holds the LPT nozzle in axial position with the retainer ring. The shim is placed between the shroud and the LPT case to prevent the wear due to nozzle fretting on the LPT case. The functions of the shrouds are defined in paragraph 2.C.
The number of shrouds in different stages are as follows:
The shroud supports an abradable for the inter-stage sealing and provide the retention for the blades. It is attached in axial position with a clamp. The shroud holds the LPT nozzle in axial position with the retainer ring. The shim is placed between the shroud and the LPT case to prevent the wear due to nozzle fretting on the LPT case. The functions of the shrouds are defined in paragraph 2.C.
The number of shrouds in different stages are as follows:
- The stage 1 has 26 shrouds.
- The stages 2 to 5 have 26 nozzles and 26 shrouds (with six vanes airfoil on each segment and one borescope nozzle segment on each stage).
- The stage 6 has 21 shrouds and 21 nozzles (with five vane airfoil on the segment and one borescope nozzle segment).
- The stage 7 has 21 nozzles (with five vane airfoil on the segment and one borescope nozzle segment).
(3) LPT Case
The LPT case provide redundant radial support to the nozzles and shrouds. The Low Pressure Turbine Active Clearance Control (LPTACC) is supported with the brackets which are attached to the LPT case. The LPT case is made of nickel alloy. It has five borescope holes located at 4 o'clock position, aft looking forward.
The LPT case is assembled:
The LPT case provide redundant radial support to the nozzles and shrouds. The Low Pressure Turbine Active Clearance Control (LPTACC) is supported with the brackets which are attached to the LPT case. The LPT case is made of nickel alloy. It has five borescope holes located at 4 o'clock position, aft looking forward.
The LPT case is assembled:
- To the Turbine Center Frame (TCF) module (Ref. AMM D/O 72-54-00-00) with the 88 studs and nuts.
- To the TRF module with the 88 studs and nuts.
(4) Insulation Plate
An insulation plate is placed between the LPT case and the nozzles to provide the thermal protection to the LPT case. A heat shield is placed between the shroud and the LPT case to provide the thermal protection to the LPT case from hot gases.
An insulation plate is placed between the LPT case and the nozzles to provide the thermal protection to the LPT case. A heat shield is placed between the shroud and the LPT case to provide the thermal protection to the LPT case from hot gases.
B. LPT Rotor
The LPT rotor consists of seven stage blades, six stage dampers, five stage disks, a spool, a cone torque, No. 5 roller bearing and ring seals. Each stage has 147 blades. The stages 1 to 6 have 147 dampers. The stage 7 has no dampers.
The LPT rotor consists of seven stage blades, six stage dampers, five stage disks, a spool, a cone torque, No. 5 roller bearing and ring seals. Each stage has 147 blades. The stages 1 to 6 have 147 dampers. The stage 7 has no dampers.
(1) Blade
The function of the blade is to provide kinetic energy to airflow. The blades are radially and axially maintained by dovetail slots and blade retainer rings. The LPT stage 1 to 6 blades are made of nickel based alloy and the LPT stage 7 blades are made of titanium alloy.
The function of the blade is to provide kinetic energy to airflow. The blades are radially and axially maintained by dovetail slots and blade retainer rings. The LPT stage 1 to 6 blades are made of nickel based alloy and the LPT stage 7 blades are made of titanium alloy.
(2) Disk and Spool
The function of the disks and spool is to provide mechanical coupling for the LPT blades. The disks and spool are life limited part. The disks 1 to 5 and spool 1 to 6 are made of nickel based alloy and have dovetail slots for installation of blades.
The function of the disks and spool is to provide mechanical coupling for the LPT blades. The disks and spool are life limited part. The disks 1 to 5 and spool 1 to 6 are made of nickel based alloy and have dovetail slots for installation of blades.
(3) LPT Cone Torque
The LPT cone torque supported by the No. 5 bearing is attached between the stages 4 and 5 disks and the LPT shaft. There is a seal teeth ring bolted on the front flange of the LPT cone torque to make sure LPT forward sump sealing as described in (Ref. AMM D/O 72-56-00-00).
The LPT cone torque supported by the No. 5 bearing is attached between the stages 4 and 5 disks and the LPT shaft. There is a seal teeth ring bolted on the front flange of the LPT cone torque to make sure LPT forward sump sealing as described in (Ref. AMM D/O 72-56-00-00).
C. Inter-Stage Sealing between Rotors and Stators
The shrouds supports an abradable for the inter-stage sealing and contributes to the retention of the blades. It is installed axially by a clamp.
The abradable of the shroud and the LPT blade teeth make sure the inter-stage sealing of the outer part of LPT.
The abradable of the nozzles with the teeth of the rotating ring and of the spool, and the seal make sure the inter-stage sealing of the inner part of the LPT.
The shrouds supports an abradable for the inter-stage sealing and contributes to the retention of the blades. It is installed axially by a clamp.
The abradable of the shroud and the LPT blade teeth make sure the inter-stage sealing of the outer part of LPT.
The abradable of the nozzles with the teeth of the rotating ring and of the spool, and the seal make sure the inter-stage sealing of the inner part of the LPT.
D. No. 5 Roller Bearing
The No. 5 roller bearing is located inside the rear sump, between the No. 5 bearing support and the LPT cone torque. The function of the No. 5 roller bearing is to provide radial support to the LPT rotor and the TRF module. It is made of low alloy steel.
The No. 5 roller bearing is attached to LPT cone torque with the No. 5 bearing nut. The outer race is attached to the No. 5 bearing support and the oil inlet cover with the 20 bolts and nuts. The No. 5 roller bearing is lubricated by the No. 5 bearing oil nozzle.
The sealing makes sure the oil containment of the rear sump:
The No. 5 roller bearing is located inside the rear sump, between the No. 5 bearing support and the LPT cone torque. The function of the No. 5 roller bearing is to provide radial support to the LPT rotor and the TRF module. It is made of low alloy steel.
The No. 5 roller bearing is attached to LPT cone torque with the No. 5 bearing nut. The outer race is attached to the No. 5 bearing support and the oil inlet cover with the 20 bolts and nuts. The No. 5 roller bearing is lubricated by the No. 5 bearing oil nozzle.
The sealing makes sure the oil containment of the rear sump:
- The No. 5 bearing support teeth and abradable and the No. 5 bearing ring seal teeth and abradable make sure the sealing for the front of the rear sump.
- The oil inlet cover teeth, the rear rotating seal abradable and the No. 5 bearing segmented seal, make sure the sealing for the rear of the rear sump.
E. LPT Cooling
The parts of the LPT are cooled to protect them against high air flow temperature as follows:
The support seal, ring seal, support flange, flange rear, turbine center frame transition duct seal, rear plate and sealing plates make sure the sealing of the turbine cavity to contain the air for disks cooling.
The ring seal is part of the LPT rotor and stator assembly.
The support seal, support flange, flange rear, rear plate and sealing plates are part of LPT stage 1 nozzle assembly (Ref. AMM D/O 72-56-00-00).
The turbine center frame transition duct seal is part of turbine center frame (Ref. AMM D/O 72-54-00-00).
The parts of the LPT are cooled to protect them against high air flow temperature as follows:
- The LPT case is cooled by the LPTACC system.
- The LPT case front flange is cooled by air from HPC stage 4 bleed system.
- LPT stage 1 to 4 disks are cooled by air coming from HPC stage 4 bleed through the turbine center frame.
The support seal, ring seal, support flange, flange rear, turbine center frame transition duct seal, rear plate and sealing plates make sure the sealing of the turbine cavity to contain the air for disks cooling.
The ring seal is part of the LPT rotor and stator assembly.
The support seal, support flange, flange rear, rear plate and sealing plates are part of LPT stage 1 nozzle assembly (Ref. AMM D/O 72-56-00-00).
The turbine center frame transition duct seal is part of turbine center frame (Ref. AMM D/O 72-54-00-00).