Patent ID: 8128341

Claim:
A steam turbine with a casing, comprising: a rotatably mounted turbine shaft arranged inside the casing and along a rotational axis of the turbine, the turbine shaft having a thrust compensating piston, wherein a flow passage is formed between the casing and the turbine shaft; a cooling line arranged within the rotor shaft that guides cooling steam in the direction of the rotational axis; an inflow line connected to the cooling line on one side, that admits an inflow of cooling steam from the flow passage into the cooling line; an outflow line connected to the other side of the cooling line, that guides cooling steam onto a generated surface of the thrust compensating piston; and a return line arranged within the casing that returns a mixture of steam to the flow passage, wherein the steam mixture is formed from cooling steam which flows out of the outflow line, and a portion of a compensating piston leakage steam that flows between the casing and the turbine shaft in the direction of the thrust compensating piston.