Radial turbine assembly with ceramic matrix composite airfoils having dovetail retention

A radial turbine rotor, the rotor comprising:

• a hub extending around an axis and comprising metallic materials shaped to have a generally diminishing diameter from a forward end to an aft end, the hub formed to include dovetail shape channels that extend primarily in an axial direction,
• a plurality of turbine blades comprising ceramic matrix composite materials, each of the plurality of turbine blades shaped to include a dovetail root arranged in a corresponding one of the dovetail shape channels of the hub and an airfoil that extends radially-outward for interaction with hot gasses that flow over the radial turbine rotor during use, and
• a retainer including a retention ring and a shaft, the retention ring is configured to couple the plurality of turbine blades to the hub, the retention ring abuts the aft end of the hub and an aft face of the dovetail root of each of the plurality of turbine blades to block axial movement of the plurality of turbine blades relative to the hub, and the shaft is a one-piece component formed to include a protrusion and a body extending axially away from the protrusion along the axis,
• wherein a radial outer surface of the body engages radially-inwardly facing surfaces of each of the hub and the retention ring to couple the hub and the retention ring together for rotation about the axis and an axial face of the protrusion that faces toward the aft end of the hub engages an aft face of the retention ring that faces away from the aft end of the hub to locate the retention ring in position relative to the body of the shaft and the hub.