Patent ID: 8137081

Claim:
A compressor unit for underwater operation, comprising: a compressor comprising a compressor rotor and a plurality of compressor stages; an electric motor comprising a stator a motor rotor and a gastight casing with an inlet and an outlet, wherein the motor rotor comprises a first radial bearing and a second radial bearing, wherein each of the first and second radial bearings is arranged at the ends of the motor rotor, the compressor rotor comprises a third radial bearing and a fourth radial bearing, each of the third and fourth radial bearings being arranged at an end of the compressor rotor, a torque transmitting coupling arranged between the compressor rotor and the motor rotor that connects the compressor and motor rotors to form a common rotor which extends in the vertical direction, wherein the compressor is designed such that, during operation of the compressor at a nominal rating of the compressor, a pressure difference is established over each of the compressor stages, and wherein, as a result of the pressure differences over the plurality of compressor stages, a thrust ensues, and wherein the ensuing thrust corresponds essentially to a weight force of the common rotor, and the orientation of the thrust is selected such that the thrust compensates for a weight force of the common rotor.