Abstract: A rotor wheel including a hub in the form of a thin-walled shell. Rotor blades are arranged in an annular pattern around the axis of the hub, each blade having at least one blade root formed with a hole. A pin extends through the hole in each blade root, and at least one retaining ring coaxial with the hub axis surrounds all the pins and absorbs radial forces produced by the blades on the pins when the rotor wheel rotates. The retaining rings and blades are fixed against axial and circumferential movement with respect to the hub. A segment between each pin and retaining ring distributes the forces of the pin to the retaining ring. The pins are mounted for radial movement with respect to the hub, and one of the mounting parts for said pins may be detachable from the hub. The hub may be dish shaped, and the pins secured at only one end to the peripheral wall of the hub, that wall having axial slots so that it may expand radially.