RADIAL TURBINE SCROLL STRUCTURE

A structure of a radial turbine scroll avoids a gas flow heading from a radially outer side toward a radially inner side in the vicinity of a tongue portion so as to restrain turbine performance from deteriorating and also reduces, to a maximum, thermal stress caused by the formation of the tongue portion. In the structure of a radial turbine scroll, an operating gas is led to flow in the radial direction from a spiral scroll formed in a turbine casing into turbine moving blades of a turbine rotor, which is positioned on the inner side of the scroll, so as to act on the turbine moving blades, and then led to flow outside in an axial direction, thereby rotatively driving the turbine rotor, wherein the scroll 4 has a partition plate 20 formed to have a length of a certain range on a line of a tongue portion formed on the inner periphery of a gas inlet portion or has a reduced height between scroll side walls at an outlet portion of a tongue portion 21 formed on the inner periphery of a gas inlet portion of the scroll, thereby avoiding a gas flow heading from the radially outer side to the radially inner side in the vicinity of the tongue portion.