Abstract: A device for providing a "soft shaft" interconnection between a prime mover and a driven machine, such as a turbine and an electric generator in a wind power plant, wherein the shafts of the two machines are coaxially aligned and are interconnected by a gearing, operatively connected to a hydraulic fluid pump/motor unit fitted between a high pressure accumulator and a low pressure accumulator in a hydraulic circuit so that the hydraulic circuit provides a predetermined torque dependency for the shaft interconnection. The gearing may be enclosed in a housing adapted to rotate about the shafts, the hydraulic unit being driven by the movements of the housing. Alternatively the hydraulic unit may be operated by a gear wheel meshing with a gear wheel, journalled in a stationary gearing housing.