VARIABLE CAPACITY TURBINE

摘要

Disclosed is a turbine comprising a turbine wheel, a turbine scroll passage defined in a turbine casing around the turbine wheel for introduction of gas to the turbine wheel, and an axial central passage defined in the turbine casing for ejection of gas from the turbine wheel, wherein: a plurality of variable nozzles are arranged outside of a throat section having a locally minimum cross section which is defined in the turbine casing around the turbine wheel. The variable nozzles may be defined by fixed vanes and moveable vanes which cooperate with each other in such a manner that each of the moveable vanes and the corresponding fixed vane define a substantially smooth and continuous airfoil. The moveable vanes may be pivotally supported by a back plate of the casing while the fixed vanes may be integrally provided with a fixed vane member having a disk portion which defines a surface opposing the inner surface of the back plate. The moveable vanes may rotate along and between these mutually opposing surfaces for varying the cross section of the nozzles defined between the fixed vanes and the moveable vanes.