The low pressure turbine rotor assembly drives the low pressure compressor through the low pressure turbine mid-shaft or from an aft drive adapter on the rear of the low pressure turbine rotor. The low pressure turbine rotor consists of 5 stages of bladed disks and a shaft sub-assembly. The rotor is supported by No 6R and the No 7R bearings and the D and E sump of the turbine rear frame.
Each low pressure turbine rotor stage consists of a bladed disk subassembly which is comprised of a disk, turbine blades, and blade retainers, interstage air seals, assembly bolts, and balance weights. Integral flanges on each disk provide assembly bolt holes in a low-stress area of the disk. Blade retainers hold the turbine blades in the axial dovetail slots.
The turbine shaft assembly is a torque cone coupled to the mid-shaft through a spline and is bolted to the stage 2 and stage 3 turbine disk flanges. It also provides the journal for the D and E-sump air/oil seal and No 6R and No 7R bearing interfaces. The rotating protion of the balance piston system mounts on the shaft aft of the No 7R bearing seals. Additionally, the aft shaft spline provides for driving the output load from the rear through the aft drive adapter.