Turbocharger with a shaft comprising a free portion

Abstract

A turbocharger includes a compressor and a compressor housing (1) surrounding the compressor, a turbine and a turbine housing (2) surrounding the turbine. The compressor housing (1) includes an inlet and an outlet for the air (4) entering a combustion chamber of an engine. The turbine housing (2) includes an inlet and an outlet for the exhaust gases (5), a shaft (3) linking the turbine and the compressor, at least one bearing for supporting and guiding the rotation of the shaft (3). The turbocharger includes attachment means (6, 7a, 7b) for attaching the turbine housing (2) to the compressor housing (1). The shaft (3) includes a free portion (8) between the two housings (1, 2), the attachment means (6, 7a, 7b) being suitable for allowing the passage of a flow of air circulating along the free portion (8) and around the turbine housing (2) and compressor housing (1).

1 . A turbocharger comprising a compressor and a compressor casing ( 1 ) that encloses said compressor, a turbine and a turbine casing ( 2 ) that encloses said turbine, said compressor casing ( 1 ) comprising an inlet and an outlet for the air ( 4 ) admitted to a combustion chamber of an engine, said turbine casing ( 2 ) comprising an inlet and an outlet for the exhaust gases ( 5 ), a shaft ( 3 ) connecting said turbine and said compressor, at least one bearing ( 9   a,    9   b ) for supporting and guiding in rotation said shaft ( 3 ), said turbocharger comprising means ( 6 ,  7   a,    7   b ) for securing the compressor casing ( 1 ) to the turbine casing ( 2 ), characterized in that said shaft ( 3 ) comprises a free portion ( 8 ) between the two casings ( 1 ,  2 ), said securing means ( 6 ,  7   a,    7   b ) being suitable for permitting the passage of a flow of air flowing along said free portion ( 8 ) and around said compressor casing ( 1 ) and turbine casing ( 2 ). 
     
     
         2 . The turbocharger as claimed in  claim 1 , in which the free portion ( 8 ) of the shaft ( 3 ) comprises air deflection means ( 10 ), said air deflection means ( 10 ) being suitable for generating a flow of air when said shaft ( 3 ) is rotating. 
     
     
         3 . The turbocharger as claimed in  claim 2 , in which the air deflection means ( 10 ) are suitable for generating a flow of air flowing in the direction from the compressor casing ( 1 ) to the turbine casing ( 2 ). 
     
     
         4 . The turbocharger as claimed in  claim 2 , in which the air deflection means comprise blades ( 10 ) attached to said shaft ( 3 ). 
     
     
         5 . The turbocharger as claimed in  claim 1 , in which a protective shell ( 12 ) is secured around said compressor casing ( 1 ), said turbine casing ( 2 ) and said free portion ( 8 ) of the shaft ( 3 ). 
     
     
         6 . The turbocharger as claimed in  claim 1 , in which the means for securing the compressor casing ( 1 ) to the turbine casing ( 2 ) comprise a plurality of bars ( 6 ). 
     
     
         7 . The turbocharger as claimed in  claim 1 , comprising a first bearing housing ( 9   a ) located between the compressor casing ( 1 ) and the free portion ( 8 ) of the shaft, and a second bearing housing ( 9   b ) located between the turbine casing ( 2 ) and the free portion of the shaft ( 8 ). 
     
     
         8 . A vehicle, characterized in that it comprises an internal combustion engine connected to a turbocharger as claimed in  claim 1 .