US Patent 7481625 Radial-flow turbine wheel

A radial-flow turbine wheel is provided. The radial-flow turbine wheel includes a hub having an outer radius gradually increasing from a front end to a rear end, a rear periphery of the hub being radially extended in a plane generally perpendicular to a center axis, and a plurality of turbine blades formed around the hub at constant intervals. A plurality of slots is formed by inward cuts at the rear periphery of the hub between the turbine blades of the hub. The turbine wheel restrains creation and propagation of cracks due to thermal stress, as well as improving a turbine efficiency.