Turbocharger

A turbocharger comprising:

• a turbine rotor;
• a housing having defined therein a turbine housing portion in which the turbine rotor rotated by exhaust gas is disposed, the housing further having defined therein an exhaust gas inlet, an exhaust gas outlet and a bearing housing portion which is integrally formed on the turbine housing portion;
• a shaft rotatably supported on the bearing housing portion via a bearing, the turbine rotor being fixed to a first end of the shaft;
• a compressor rotor fixed to a second end of the shaft, the compressor rotor being disposed in a compressor housing fixed to the bearing housing portion;
• a bypass passage formed on the turbine housing portion so as to communicatively connect the exhaust gas inlet and the exhaust gas outlet while bypassing the turbine rotor;
• a waste gate valve disposed in the bypass passage and operatively positioned to open or close the bypass passage in response to a boost pressure;
• and
• a nozzle member, which is detachable from the housing, fixedly positioned with the exhaust gas outlet of the housing such that a first end of the nozzle member is adjacent to the turbine rotor while maintaining a predetermined clearance therefrom and a second end of the nozzle member defines an opening of an exhaust gas outlet side of the bypass passage oriented along a direction of the main flow of the exhaust gas discharged from the turbine rotor, wherein
• the shaft is formed with a diameter that increases from the second end to the first end, and
• the first end of the nozzle member is further formed with a shape corresponding to and opposingly positioned with outer circumferential portions of the turbine rotor so as to maintain the predetermined clearance therewith.