
Typically subsea rotors have considerably smaller rotor diameters than wind turbines of the same nominal power. This is based on the fact that, in connection with the roughly 850fold higher density of water compared to air, high forces are applied on the complete system even at low flow velocities. A straightforward and very robust way of transforming the rotor input power into power to drive a fast turning generator is based on the application of a continuous variable hydrostatic transmission as a hydraulic converter. In this case the rotor rotation is transferred to a low speed high volume displacement device which generates a hydraulic flow. This flow is driving with high efficiency a variable high speed axial piston motor coupled with a generator.






