Compressor

Abstract

A compressor includes an impeller including blades extending along a shroud. Each of the blades includes a leading edge, a trailing edge, and a tip edge connecting the leading edge and the trailing edge and opposing the shroud. The tip edge has a central curve extending along a center of a thickness of the tip edge from the leading edge to the trailing edge. The central curve has a tangential line touching a contact in the central curve. The tangential line has a tip edge inclination angle made by the rotation axis and the tangential line viewed in a reference direction which passes the contact and which is perpendicular to the rotation axis. The tip edge inclination angle increases as the contact approaches a first maximum inclination point in the central curve. The first maximum inclination point is separated from both the leading edge and the trailing edge.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2016-083764, filed Apr. 19, 2016, entitled “Compressor.” The contents of this application are incorporated herein by reference in their entirety.BACKGROUND1. Field[0002]The present disclosure relates to a compressor.2. Description of the Related Art[0003]Hitherto, in a case in which a fixed diffuser is disposed downstream of a compressor that compresses an intake flowing in an intake passage of an internal-combustion engine, the air compressed in the compressor impeller generates a nozzle wake (a pressure fluctuation) when passing through the fixed diffuser. With the above, the compressor impeller positioned upstream receives exciting force caused by the nozzle wake and a phenomenon in which the blades of the compressor impeller vibrate occurs.[0004]Responding to the above, from the viewpoint of securing blade strength against the blade vibrat...

AI Technical Summary

Benefits of technology

The patent text discusses a compressor with a blade that has a semi-elliptic cylindrical shape at the trailing edge. This design helps improve the efficiency of supercharging by preventing the fluid from separating at that point.

Problems solved by technology

However, there is a trade-off relationship between the blade strength and the aerodynamic performance of the compressor impeller.

Loss is caused by the thickness of the blade creating a limit to the above adjustment.

Meanwhile, cutting off (cutback) of the trailing edge of the blade of the compressor impeller has been performed; however, in such a case, the compressed air flowing out from the compressor impeller flows into the fixed diffuser in an unstable state.

Accordingly, as a result of decrease in the static pressure efficiency at the compressor impeller outlet, a problem of decrease in supercharging efficiency occurs.

Images