A turbomachinery electric generator arrangement includes a rotary compressor, a generator having a rotary armature and a stator, a combustion chamber to which compressed gas is directed from the compressor, a rotary turbine to which combustion product is directed from the combustion chamber and a bearing arrangement supporting in rotation the rotary compressor, rotary armature and rotary turbine. Compressed gas for cooling components of the arrangement is directed from the rotary compressor, typically being tapped off from a subsidiary gas output upstream of a primary gas outlet. Bearing thermal shielding and modular construction of components are also features of the arrangement.