DOC AIRBUS | AMM A320FLPT SHAFT - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
Low Pressure Turbine Shaft AssemblyA. Low pressure turbine shaft
(1) The low pressure turbine (LPT) shaft module connects the fan shaft with the LPT rotor. It is composed of the LPT shaft, center vent tube and center vent tube rear extension duct. The aft end of the LPT shaft is supported by the No. 5 bearing ; its forward end is coupled with the fan shaft. The LPT shaft has 2 functions : coupling the fan/booster rotor with the LPT rotor and providing for high pressure turbine rear support through the No. 4 bearing. In addition, the LPT shaft houses the center vent tube of the forward and aft engine sumps.
(2) The LPT shaft module consists of the following major parts :
(a) LPT shaft.
(b) No. 4 roller bearing.
(c) No. 5 roller bearing.
2. Description
A. Low pressure Turbine Shaft
(1) The LPT shaft is made of steel alloy. It is located concentrically in the high pressure rotor system. Its forward end is provided with outer splines for coupling with the fan shaft. It is axially retained by a shoulder and a coupling nut. At the aft end of the shaft, the No. 4 and 5 bearings are located axially on both sides of an integral hub.
On the rear face, the hub supports 2 rotating air/oil seals which control the air circulation through the LPT rotor and the sump pressurizing air. On the front face, the hub supports the turbine rotor support.
On the rear face, the hub supports 2 rotating air/oil seals which control the air circulation through the LPT rotor and the sump pressurizing air. On the front face, the hub supports the turbine rotor support.
(2) The center vent tube is made of composite material. It is installed inside the LPT shaft. Its forward end is inserted in the LPT shaft plug and its aft end is supported by the LPT shaft hub. It is maintained coaxial in the LPT shaft through 2 inner locating diameters: one at the front end of the LPT shaft; the other at the rear end of the shaft.
(3) The center vent tube rear extension duct is installed at the aft end of the center vent tube. Its relative angular position is maintained by locating pins, and axial retention is provided by an inner nut threaded into the center vent tube. A centrifugal air/oil separator is retained by a nut against a central shoulder on the duct. Its relative angular position is maintained by slots at its front end.
B. No. 4 Bearing
The no. 4 bearing, which takes the high pressure turbine (HPT) rotor radial loads, is a roller bearing installed between the HPT rear shaft and the LPT shaft. The bearing outer race is housed in the HPT rear shaft bore, and its inner race is bolted to the front face of the LPT shaft integral hub. The inner race has a shoulder which would act as an emergency bearing in case of roller failure. The inner race front end is provided with a sump air seal.
The no. 4 bearing, which takes the high pressure turbine (HPT) rotor radial loads, is a roller bearing installed between the HPT rear shaft and the LPT shaft. The bearing outer race is housed in the HPT rear shaft bore, and its inner race is bolted to the front face of the LPT shaft integral hub. The inner race has a shoulder which would act as an emergency bearing in case of roller failure. The inner race front end is provided with a sump air seal.
C. No. 5 Bearing
The No. 5 Bearing supports the LPT rotor aft end inside the turbine frame and takes the radial loads. The bearing outer race is mounted in the turbine frame and its inner race is mounted at the rear of the LPT shaft integral hub. Axial retention is provided by a retainer nut.
Retainer nut relative position is maintained by rivet.
The No. 5 Bearing supports the LPT rotor aft end inside the turbine frame and takes the radial loads. The bearing outer race is mounted in the turbine frame and its inner race is mounted at the rear of the LPT shaft integral hub. Axial retention is provided by a retainer nut.
Retainer nut relative position is maintained by rivet.