Abstract: A shaft seal arrangement of a turbocharger for an internal combustion engine having a throttle valve disposed upstream of a compressor of the turbocharger. The shaft seal arrangement is comprised of first and second seal rings fitted on a cylindrical thrust spacer mounted on a rotatable shaft on which turbine and compresser wheels are mounted. The first and second rings are located spaced from each other and positioned between the compressor and bearings for the rotatable shaft. An annular air chamber is formed between the first and second seal rings and supplied with atmospheric air through an air supply passage.