Propeller, engine cooling device comprising such a propeller, and mould for producing said propeller

An injection mold of a propeller (1) comprising an outer shell (4), an inner hub (2), blades (3) extending radially between said hub (2) and said shell (4), said shell (4) having two flanks (41, 42) connected by an elbow piece and comprising a polymer material reinforced by a fibrous reinforcement and being integral, unitary, and one-piece, the blades (3) extending from the hub (2) to the shell (4), wherein one of the two flanks (41, 42) has an outer surface and inner surface each being planar and extending axially and the other of the two flanks has an inner surface and an outer surface being planar and extending radially, the injection mold comprising an area corresponding to the hub (2), an area corresponding to each of the blades (3) and an area corresponding to the shell (4), the area corresponding to the shell (4) having in a first half of a length, but not an entire length, of at least one of the two flanks (41, 42) from the elbow piece to its free end a thickness (e1, e2) is gradually reduced and wherein a remainder of the length from the first half of the length to the free end of the at least one of the two flanks (41, 42) a thickness is substantially uniform, wherein a reduction in thickness (e1, e2) in the shell (4) is from 30% to 50% between a thickness of the shell (4) in a region of the elbow piece and a thickness of the shell (4) in a region of the free end.