Abstract: A device and method for axially displacing at least one turbine rotor relative to at least one corresponding turbine stator in a multistage axial turbine is disclosed. The turbine shaft is provided with a split design and has a first axially displaceable shaft half, which is connected via a turbine disc to the turbine rotor and via a torque coupling to the second shaft half. By axially displacing the turbine rotor relative to the turbine stator and by controlling this axial displacement, the operation of the turbine is held in its possible optimum of efficiency.

Abstract: A rotor shaft provided with a fan is rotatably supported by pneumatic bearings for the purpose of high speed rotation with low noise. The rotor shaft provided with the fan can also be supported at one end by a resilient bearing so as to provide high speed rotation even if the concentricity of the bearings is low.