Abstract: A multiple vane, variable pitch, fluid active or reactive device to move or be moved by a fluid including first and second wheels each rotatable about its axis and the axes disposed in selected parallel offset relation. Aperatures provided in the first wheel receive rotatable vane shafts. A vane is provided on each shaft and a distal end of each shaft extends through the aperture. Follower members are connected to the distal ends of the shaft and extend generally parallel to the chord line of the vanes to control the pitch angle of the vanes. The second wheel is inset a selected distance from the first wheel and provides cams that extend outwardly from the second wheel to engage the follower members of the first wheel. A drive member is provided so that a rotational force applied to either wheel is transferred by a gear drive to the other wheel.