| 摘要 |
<p>A turbocharger comprising a turbine for extracting energy from exhaust gas flowing through an exhaust gas passage, a compressor for pressurising air flowing through an air passage, a rotor shaft 3 connecting the turbine 5 to the compressor, a bearing supporting the shaft at the turbine end thereof, and a two part seal axially located between the bearing and the turbine to seal the bearing against hot exhaust gases. The first part of the seal 1 is a mechanical seal which extends between a housing 7 surrounding the shaft and the shaft. The second part of the seal is an air seal axially located between the mechanical seal and the turbine. The air seal includes an air swirler through which, in use, pressurised sealing air is injected through injection holes 8 radially inwardly to fill an annular gap which extends circumferentially around the shaft and extends axially between the mechanical seal and the exhaust gas passage. The swirler swirls the sealing air in the direction of rotation of the shaft.</p> |
