Abstract: A connection arrangement comprising a shaft having an axial through hole, a tie rod located inside the axial through hole, an impeller comprising a solid hub, a plurality of blades, and an integral stub protruding axially from the solid hub; at an end of the tie rod there is an integral body having a shape radially protruding from the tie rod; the stub has a cavity for receiving the body and an axial hole for inserting the body into the cavity; the stub axial hole has a shape corresponding to the shape of the body; the cavity is so sized and shaped as to allow rotation of the body inside the cavity and trapping of the body in the cavity once rotated; the shaft and the impeller are coupled together by a coupling.

Abstract: A connection arrangement comprising a shaft having an axial through hole, a tie rod located inside the axial through hole, an impeller comprising a solid hub, a plurality of blades, and an integral stub protruding axially from the solid hub; at an end of the tie rod there is an integral body having a shape radially protruding from the tie rod; the stub has a cavity for receiving the body and an axial hole for inserting the body into the cavity; the stub axial hole has a shape corresponding to the shape of the body; the cavity is so sized and shaped as to allow rotation of the body inside the cavity and trapping of the body in the cavity once rotated; the shaft and the impeller are coupled together by a coupling.