Patent ID: 6345503
Filing Date: 2002-02-12
Classification: F02B,F04D,F05B,Y02T

Abstract:
A method of configuring a compressor in a turbocharger for use in an internal combustion engine, comprising the steps of:providing a multi-stage compressor including a first compressor wheel carried by a shaft, a first inlet associated with said first compressor wheel, a radially extending first outlet associated with said first compressor wheel, a second compressor wheel carried by said shaft, a second inlet associated with said second compressor wheel, and a radially extending second outlet associated with said second compressor wheel, said first compressor wheel being made of a first material, said second compressor wheel being made of a second material; fluidly interconnecting in series said first outlet associated with said first compressor wheel with said second inlet associated with said second compressor wheel using an interstage duct; selecting a total pressure ratio to be provided by said multi-stage compressor; ascertaining a first pressure ratio provided by said first compressor wheel at an operating speed; sizing said second compressor wheel to provide a second pressure ratio, dependent upon said total pressure ratio and said first pressure ratio; determining a stress on said second compressor wheel at said operating speed; determining a temperature within said interstage duct at said operating speed, and selecting said second material from which said second compressor wheel is made, dependent upon each of said stress determining step and said temperature determining step, said second material being denser than and capable of operating at higher temperatures than said first material.