The LM6000 turbine rear frame (TRF) is one piece-casting that provides the gas turbine exhaust flow path and the supporting extructure for the D and E sump, the low pressure turbine rotor thrust balance assembly, the low pressure turbine rotor shaft, and the aft drive adapter.
In the turbine rear frame, fourteen radial struts function as outlet guide vanes to straighten the exhaust airflow into the exhaust diffuser for enhanced performance. Lubrication oil supply and scavange lines for the D and E sump and the low pressure turbine rotor speed sensors(XNSD-A and XNSD-B) are routed through the struts.
The low pressure turbine rotor thrust balance system is designed to maintain the axial thrust loading on the No 1B thrust bearing within designed limits. The balance piston static seal is mounted to the turbine rear frame hub. Stage 11 high pressure compressor bleed air is routed through the three turbine rear frame struts to generate the required axial loading through the rotor thrust balance system.
Below, schematic of the GE LM6000 machine, showing the turbine rear frame
