| 摘要 |
A seal system for a four cycle engine turbocharger includes dual phase seals for limiting leakage from lubricated rotor support bearings to a turbine and/or compressor wheel of a rotor operational over an extended speed range. The dual phase seal combines features of a labyrinth seal, effective in a higher portion of the turbocharger rotor speed range, with features of an auger seal, found to be effective in a lower portion of the rotor speed range. The dual phase seals each include an outer cylinder on the roto r between a bearing and an associated wheel, an inner cylinder carried by a rotor support and surrounding the outer cylinder with close clearance, auger seal grooving formed in one of the cylinders on a portion thereof toward the bearing, labyrinth seal grooving formed in one of the cylinders on a portion thereof toward the wheel, and a pressure air supply to the labyrinth seal at a pressure which is reduced at rotor speeds in a lower portion of the speed range. Air pressure is supplied from an output of the compressor wheel to th e labyrinth seal grooving for both the turbine and compressor ends of the roto r shaft. The dual phase seals operate without wear and provide cost effective and dependable rotor sealing at all rotor speeds without fragile or wearing parts, failure of which could causedamage to other components.
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