Compressor housing for turbocharger

Abstract

A compressor impeller 2 has a plurality of long blades 2 a and short blades 2 b alternately arranged in a circumferential direction, and an inner surface of a compressor housing 10 is provided with an annular groove 12 which surrounds vicinities of leading edge tip portions of the short blades 2 b in a circumferential direction and is concave outward so as not to communicate with a suction port of a compressor.

1 . A compressor housing for a turbocharger for rotationally driving a turbine impeller using exhaust gas of an internal combustion engine and transmitting the rotation force to a compressor impeller to be rotationally driven so that air or air-fuel mixture is compressed and supplied to the internal combustion engine,
 wherein the compressor impeller has a plurality of long blades and short blades alternately arranged in a circumferential direction, and   wherein an inner surface of the compressor housing is provided with an annular groove which surrounds vicinities of leading edge tip portions of the short blades in a circumferential direction and is concave outward so as not to communicate with a suction port of a compressor.   
     
     
         2 . The compressor housing for the turbocharger according to  claim 1 ,
 wherein an axial center of the annular groove is located within 5 mm from the leading edge tip portions of the short blades in an axial direction on an upstream or downstream side thereof, an axial groove width is no less than 2.5 mm and no more than 10 mm, and a maximum diameter of the annular groove is less than 1.2 times a diameter of each leading edge tip portion of the short blades.   
     
     
         3 . The compressor housing for the turbocharger according to  claim 1 ,
 wherein the annular groove extends outward from the inner surface of the compressor housing so as to be perpendicular or inclined with respect to a rotary shaft of a compressor.