A hydrodynamic turbine comprising: - an electric energy generator; - a rotor; - a rotation shaft, said rotation shaft having a first end and a second end; - said first end of said rotation shaft being engaged with said rotor; - said second end of said rotation shaft being coupled to said electric energy generator; wherein said rotor comprises: - a first connection system and a second connection system, each connection system (41, 42) being integrally engaged with said rotation shaft; - a first blade module comprising at least two blades (51a, 51b), each blade (51a, 51b) comprising an inner cavity having a substantially rectangular cross-section and being equipped with a first end and a second end; wherein each of the first and second connection systems (41, 42) comprises a plurality of elongate engagement elements (84, 92) having a substantially rectangular cross-section; each elongate engagement element (84, 92) being coupled to the cavity of a respective blade (51a, 51b); wherein each blade (51a, 51b) of said first blade module is coupled, at a first end thereof, to said first connection system and, at a second end thereof, to said second connection system wherein at least one of said first and second connection systems (41, 42) comprises a sandwich structure; said sandwich structure comprising: - a pair of tightening plates (81a, 81b) fitted onto said rotation shaft; - a pair of coupling shims (82a, 82b); wherein each elongate engagement element is a rectangular shim; wherein said rectangular shim is inserted into said inner cavity at a respective end of a respective blade; wherein said end of a respective blade and said rectangular shim are interposed between said pair of coupling shims (82a, 82b) and said pair of tightening plates (81a, 81b). - an electric energy generator; - a rotor; - a rotation shaft, said rotation shaft having a first end and a second end; - said first end of said rotation shaft being engaged with said rotor; - said second end of said rotation shaft being coupled to said electric energy generator; - said first end of said rotation shaft being engaged with said rotor; - said second end of said rotation shaft being coupled to said electric energy generator; wherein said rotor comprises: - a first connection system and a second connection system, each connection system (41, 42) being integrally engaged with said rotation shaft; - a first blade module comprising at least two blades (51a, 51b), each blade (51a, 51b) comprising an inner cavity having a substantially rectangular cross-section and being equipped with a first end and a second end; - a first connection system and a second connection system, each connection system (41, 42) being integrally engaged with said rotation shaft; - a first blade module comprising at least two blades (51a, 51b), each blade (51a, 51b) comprising an inner cavity having a substantially rectangular cross-section and being equipped with a first end and a second end; wherein each of the first and second connection systems (41, 42) comprises a plurality of elongate engagement elements (84, 92) having a substantially rectangular cross-section; each elongate engagement element (84, 92) being coupled to the cavity of a respective blade (51a, 51b); wherein each blade (51a, 51b) of said first blade module is coupled, at a first end thereof, to said first connection system and, at a second end thereof, to said second connection system wherein at least one of said first and second connection systems (41, 42) comprises a sandwich structure; said sandwich structure comprising: - a pair of tightening plates (81a, 81b) fitted onto said rotation shaft; - a pair of coupling shims (82a, 82b); - a pair of tightening plates (81a, 81b) fitted onto said rotation shaft; - a pair of coupling shims (82a, 82b); wherein each elongate engagement element is a rectangular shim; wherein said rectangular shim is inserted into said inner cavity at a respective end of a respective blade; wherein said end of a respective blade and said rectangular shim are interposed between said pair of coupling shims (82a, 82b) and said pair of tightening plates (81a, 81b).