Abstract: A wheel intended to work with a fluid includes wing-shaped components (2) arranged around a central shaft (1) generally perpendicular to the direction of relative movement of the fluid (5). The wing-shaped components are articulated along pivoting axes (3) parallel to the central shaft and their orientation during the rotation around the central shaft is determined by a control mechanism (6,7,10, 11 and 16) made so that, in each angular position of the wheel, the planes (12) aligned along the pivoting axes of the wings and perpendicular to the main planes of the latter intersect approximately along the same straight line (13) located on the outside of the trajectory cylinder of the axes of the wings (4). The control mechanism has, for this purpose, an annular part (6) with an axis of rotation (8) parallel to but distinct from that of the central shaft (1) and adjustment parts (10) sliding on rods (9) mounted tangentially to annular part (6).