Abstract: A turbo-generator machine for producing a supply of cooled air and a supply of electric power has a permanent magnet generator fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is supplied thereto. Magnetic bearings support the shaft radially for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. Power for the magnetic bearings is supplied by the turbo-generator during operation. Generator air gap is sized in coordination with the magnetic bearing air gap, and the generator stator and shaft are sized to minimize leakage flux from the generator to minimize interaction between the permanent magnet rotor and the magnetic bearings.

Abstract: A turbo-generator machine for producing a supply of cooled air and a supply of electric power has a permanent magnet generator fixed to a shaft which is driven by a turbine rotor, the turbine serving to expand air which is supplied thereto. Magnetic bearings support the shaft radially for rotation about a precisely established axis while a magnetic thrust bearing keeps the shaft in a precisely fixed axial position. Power for the magnetic bearings is supplied by the turbo-generator during operation. Generator air gap is sized in coordination with the magnetic bearing air gap, and the generator stator and shaft are sized to minimize leakage flux from the generator to minimize interaction between the permanent magnet rotor and the magnetic bearings.