Wellendichtungseinrichtung für Turbolader.

摘要

A shaft seal arrangement of a turbocharger (1) for an internal combustion engine having a throttle valve disposed upstream of a compressor of the turbocharger. First and second seal rings (12,13) are fitted on a cylindrical thrust spacer (11) fixed on a rotatable shaft (2) on which turbine and compressor wheels (4,3) are mounted. The seal rings (12,13) are spaced from each other and positioned between the compressor and bearings (6) for the shaft (2). An annular air chamber 14 between the seal rings (12,13) is supplied with atmospheric air through an air supply passage (15). The cross-sectional area of the air supply passage (15) is such that a pressure difference between the air chamber (14) and the bearing side is prevented from exceeding an experimental pressure difference value at which oil leak from the bearing side to the compressor side begins, thereby effectively avoiding oil leakage even in an engine operating condition in which the throttle valve is fully closed.