Subsea pressure booster

A subsea turbomachine for boosting pressure of a petroleum fluid flow from subsea petroleum production wells or systems, the subsea turbomachine comprising:

• an electric motor comprising a rotor and a stator, the rotor and the stator being disposed in a motor compartment;
• a pump or compressor, disposed in a pump or compressor compartment;
• a petroleum fluid inlet to and a petroleum fluid outlet from the pump or compressor compartment;
• a common pressure housing for the motor compartment and the compressor or pump compartment;
• a magnetic gear inside the common pressure housing for operative connection between the electric motor and the compressor or the pump;
• an electric motor shaft and one pump or compressor shaft;
• wherein an outer ring of the magnetic gear is connected to the electric motor shaft and an inner ring of the magnetic gear is connected to the one pump or compressor shaft, or opposite;
• wherein the electric motor shaft and the one pump or compressor shaft are suspended in bearings;
• and
• a partition inside the common pressure housing, arranged between the inner and outer magnetic gear rings so as to separate the motor compartment hermetically from the pump or compressor compartment, wherein the subsea turbomachine has no external barrier fluid system or supply.