An electromechanical system comprising: - an electric machine (108, 208), - a rotating apparatus (109, 209) being a turbo-compressor, and - a joint element (101, 201) configured to mechanically connect the electric machine to the rotating apparatus, wherein the joint element comprises: - a coupling element (102, 202) connecting a shaft of the electric machine to a shaft of the rotating apparatus in a torque transferring way, and - a tubular portion (103, 203) surrounding the coupling element, wherein: - a first rim of the tubular portion comprises a seal (104, 204) for arranging a first hermetic joint between the first rim of the tubular portion and an outer surface of the electric machine, - a second rim of the tubular portion comprises a seal (105, 205) for arranging a second hermetic joint between the second rim of the tubular portion and an outer surface of the rotating apparatus, and - the tubular portion comprises an opening (106, 206) and a lid (107, 207) for hermetically closing the opening, the opening providing access to the coupling element from outside the tubular portion. characterized in that the electromechanical system comprises a piping (110, 210) configured to guide a part of an input flow of the turbo-compressor to flow through an airgap of the electric machine. - an electric machine (108, 208), - a rotating apparatus (109, 209) being a turbo-compressor, and - a joint element (101, 201) configured to mechanically connect the electric machine to the rotating apparatus, wherein the joint element comprises: - a coupling element (102, 202) connecting a shaft of the electric machine to a shaft of the rotating apparatus in a torque transferring way, and - a tubular portion (103, 203) surrounding the coupling element, - a coupling element (102, 202) connecting a shaft of the electric machine to a shaft of the rotating apparatus in a torque transferring way, and - a tubular portion (103, 203) surrounding the coupling element, wherein: - a first rim of the tubular portion comprises a seal (104, 204) for arranging a first hermetic joint between the first rim of the tubular portion and an outer surface of the electric machine, - a second rim of the tubular portion comprises a seal (105, 205) for arranging a second hermetic joint between the second rim of the tubular portion and an outer surface of the rotating apparatus, and - the tubular portion comprises an opening (106, 206) and a lid (107, 207) for hermetically closing the opening, the opening providing access to the coupling element from outside the tubular portion. - a first rim of the tubular portion comprises a seal (104, 204) for arranging a first hermetic joint between the first rim of the tubular portion and an outer surface of the electric machine, - a second rim of the tubular portion comprises a seal (105, 205) for arranging a second hermetic joint between the second rim of the tubular portion and an outer surface of the rotating apparatus, and - the tubular portion comprises an opening (106, 206) and a lid (107, 207) for hermetically closing the opening, the opening providing access to the coupling element from outside the tubular portion. characterized in that the electromechanical system comprises a piping (110, 210) configured to guide a part of an input flow of the turbo-compressor to flow through an airgap of the electric machine.