The ECT has an integrated gearbox. That is, the turbine rotor is directly mounted on the high-speed (input) shaft of the gearbox, with no turbine-module bearings necessary. A steam and oil seal isolates the gearbox from the turbine module. The advantages of this construction over a conventional separate gearbox are as follows:
Elimination of high-speed couplings, along with its attendant balance and misalignment problems.
Elimination of two turbine bearings, as the gearbox input shaft bearings support the turbine rotor.
Elimination of one steam seal, as there is only one seal for the turbine module.
Compact arrangement, with minimum foot-print and weight.
This is essential for incidental power applications in existing plants, where space is always a severe constraint.
The elimination of so many critical parts enhances reliability and lowers the cost of the system.