Turbomachine having a compensating piston

Abstract

A turbomachine including a compensating piston that is sealed by means of a seal with respect to a stator is provided. Conventional compensating pistons consume significant amounts of process fluid, which can cause a considerable loss of efficiency. The turbomachine provides the solution in that the stator partially carrying the seal is designed to be axially moveable in the housing such that the permeability of the seal can be changed in this way.

1 .- 6 . (canceled) 
     
     
         7 . A turbomachine, comprising:
 a balance piston,   wherein the balance piston includes a shaft step on a rotor, which extends along a machine axis, and a seal seals a gap between the rotor and a stator so that a cavity, which is adjacent to a first side of the seal and is filled with process fluid during operation may have a pressure which by a differential pressure across the seal, differs from that on the other side of the seal,   wherein the shaft step is adjacent to the cavity,   wherein the stator is designed with guided movement capability in such a way that the gap may be increased and decreased, and   wherein a balance line opens into the cavity, by means of which process fluid may be fed to the cavity or may be drained from the cavity.   
     
     
         8 . The turbomachine as claimed in  claim 7 , wherein a surface of the stator is adjacent to the cavity and is designed in such a way that, depending upon the pressure in the cavity, it is displaced in such a way that the gap increases or decreases. 
     
     
         9 . The turbomachine as claimed in  claims 7 , wherein the stator comprises an elastic element which, depending upon a position of the stator, creates a restoring force. 
     
     
         10 . The turbomachine as claimed in  claim 7 , wherein the gap does not extend parallel to the machine axis. 
     
     
         11 . The turbomachine as claimed in  claim 9 , wherein a control valve is in the balance line, by means of which feeding the process fluid or draining of process fluid may be adjusted. 
     
     
         12 . The turbomachine as claimed in  claim 11 , wherein the position of the stator may be adjusted in axial movability by means of the control valve during operation.