Patent ID: 6608418
Filing Date: 2003-08-19
Classification: F01D,F05D,F16C,H02K,Y02T

Abstract:
A turbo-generator, comprising:a housing; a shaft disposed in the housing and having a central axis; a permanent magnet generator mounted on the shaft; a turbine mounted on the shaft in axially spaced relation with the permanent magnet generator and having inlet means for receiving gas, the turbine being driven by the gas and acting through the shaft to drive the permanent magnet generator, the gas received by the turbine expanding therein, being cooled as a result of expanding and being exhausted as a chilled gas by the turbine; a collar fixed to the shaft, the collar being made of a non-permanent-magnetic material having high magnetic saturation; axially spaced bearings for radially supporting the shaft for rotation in the housing, each of the bearings comprising a plurality of electromagnets mounted within the housing and spaced angularly around the collar, the electromagnets comprising selectively energizable electrical coils for producing magnetic forces suspending the shaft radially within the housing; radial position sensors for sensing the radial position of the axis of the shaft; a magnetic bearing controller responsive to the radial position sensors for varying the energization of the coils to keep the axis of the shaft in coincidence with a predetermined axis; an additional bearing for maintaining the shaft in a predetermined axial position in the housing, the additional bearing comprising axially spaced and axially opposing electromagnets mounted within the housing and positioned substantially coaxial with the shaft; a disc rigid with and projecting radially from the shaft and located between the axially opposing electromagnets, the axially opposing electromagnets comprising selectively energizable electrical coils for producing magnetic forces acting in axially opposing relation on the disc; an axial position sensor for detecting the axial position of the shaft; and wherein the magnetic bearing controller is responsive to the axial position sensor for varying the energization of the coils of the axially opposing electromagnets to keep the shaft in a predetermined axial position.