Variable geometry turbochargers.

摘要

A turbocharger includes a turbine (1) connected to a compressor (2) through a bearing casing (3) which defines an annular cooling passage (27). The turbine includes a housing (4) which defines a space accommodating a turbine wheel (24) and an inlet passage which communicates with the said space via an annular passage. A plurality of circumferentially spaced nozzle blades (9) are positioned in the said annular passage for guiding exhaust gases to the turbine wheel (24). The nozzle blades (9) are connected to one end of respective rotatable nozzle shafts (35) whose other end is connected to a common nozzle blade drive mechanism (37) which is operable to adjust the angle of all the nozzle blades (9) simultaneously. The nozzle shafts (35) are rotatably supported by the bearing casing (3) at positions adjacent the cooling fluid passage (27).