Centrifugal compressor

Abstract

A centrifugal compressor is equipped with a resin housing, that is made in a manner such that compression efficiency is not lost and merits such as weight and cost reduction are not cancelled out. The turbo charger housing comprises a volute section, a channel formation section, and an impeller that is fixed in the center of the channel formation section to a rotating shaft. An annular shroud is disposed in a recess formed on the inner wall of the channel formation section. The annular shroud forms the outer walls of a channel and a diffuser for compressed gas. The edge of the annular shroud spaced from a partition wall, which forms a portion of a bearing housing. If the resin housing undergoes thermal deformation, the dimensions of a gap between the annular shroud and the curved profile of a blade is maintained.

Description

TECHNICAL FIELD[0001]The present invention relates to a centrifugal compressor provided with a housing made of resin which is used in a turbocharger or the like.BACKGROUND ART[0002]A turbocharger installed in a vehicle or the like, drives a compressor by a exhaust turbine which is driven by energy of exhaust gas, compresses intake air in the compressor and supplies the compressed air to an engine. This type of turbocharger is provided with a bearing housing between a turbine housing of the exhaust turbine and a compressor housing for a turbo compressor. The bearing housing movably supports the rotating shaft rotatably. On the rotating shaft arranged through the bearing housing, an impeller of the turbo compressor and a wheel of the exhaust turbine are fixed.[0003]The bearing housing houses a bearing mechanism for movably supporting the rotating shaft rotatably. Between the bearing housing and the compressor housing, a seal wall is interposed to form a flow path for gas which is encl...

AI Technical Summary

Benefits of technology

[0031]According to the centrifugal compressor of the present invention, the centrifugal compressor is provided with: an impeller which includes a plurality of blades fixed radially to a rotating shaft; a resin housing which is arranged around the impeller and which is made of resin. Between the impeller and the resin housing, a flow path for a gas to be compressed is formed by an outer periphery of the impeller and an inner wall of a path forming section of the resin housing, the gas flowing in the flow path from an axial direction to a radial direction of the impeller. The inner wall of the path forming section of the resin housing is carved to form a depression in which an annular shroud is provided, the annular shroud being made of one of a metal and a ceramic material and forming an outer surface of the flow path where the impeller is arranged and an outer surface of a diffuser which is arranged on an outlet side of the flow path. The annular shroud is fixed to a wall facing the annular shroud at the diffuser.

[0032]Therefore, the clearance between the annular shroud and the curved profile of the blade can be kept at a set dimension, thereby maintaining a high compression efficiency, and by providing the annular shroud, there is no need to make the resin housing thicker or to provide a reinforcement rib in the resin housing and thus, the benefits such as a lighter weight or cost reduction of the resin housing can be obtained.

Problems solved by technology

By this, the clearance T becomes wider and the gas leaks from the wider clearance T, resulting in a decrease in compression efficiency.

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