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 being integrally engaged with said rotation shaft ; - a first blade module comprising at least two blades , each blade 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 comprises a plurality of elongate engagement elements having a substantially rectangular cross-section; each elongate engagement element being coupled to the cavity of a respective blade ; wherein each blade 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 comprises a sandwich structure ; said sandwich structure comprising: - a pair of tightening plates fitted onto said rotation shaft ; - a pair of coupling shims ; 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 and said pair of tightening plates . - 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 being integrally engaged with said rotation shaft ; - a first blade module comprising at least two blades , each blade 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 being integrally engaged with said rotation shaft ; - a first blade module comprising at least two blades , each blade 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 comprises a plurality of elongate engagement elements having a substantially rectangular cross-section; each elongate engagement element being coupled to the cavity of a respective blade ; wherein each blade 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 comprises a sandwich structure ; said sandwich structure comprising: - a pair of tightening plates fitted onto said rotation shaft ; - a pair of coupling shims ; - a pair of tightening plates fitted onto said rotation shaft ; - a pair of coupling shims ; 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 and said pair of tightening plates . <EOS>