A wheel for a rotating flow machine, comprising a rotor (1) on which a plurality of blades (2) are arranged projecting radially from the rotor (1), with each blade (2) having a root (3) attached to the rotor (1) and a blade top (4). In addition, the wheel comprises a ring (5) arranged concentrically in relation to the rotor (1) outside the blade tops (4) in such a way that the ring (5) and the blades (2) overlap each other when the ring and the blades are viewed in a radial direction, which ring (5) is arranged to be caused to rotate by the blades (2) when the rotor (1) rotates. The extent (9) of the blades (2) in a radial direction and the internal dimension (10) of the ring (5) are matched to each other in such a way that there is a clearance (Δ) between each blade top (4) and the ring (5) in radial direction when the rotor (1) is not rotating.