PURPOSE: To conform the operation range of an engine with a wide range by moving a surge line to the low flow side. CONSTITUTION: An annular chamber 8 is provided in a shroud part 3. A first communicating path 9 is provided for communicating the chamber 8 with the install position of an impeller 1 in the radial direction. A second communicating path 10 is provided for communicating the chamber 8 with the upstream position of the impeller 11 in the radial direction. With the second communicating path 10 as a boundary, the impeller side inner peripheral surface part 3b of the shroud part 3 is formed with a difference in level in such a manner as to have a larger diameter than the intake side inner peripheral surface part. Some of air sucked by the impeller 1 is circulated from the first communicating path 9 through the chamber 8 and the second communicating path 10. COPYRIGHT: (C)1994,JPO&Japio

Compressor housing of turbo charger

PURPOSE:To prevent the reduction of the air quantity and reduce noise by arranging a thin cylinder in a case, connecting a bell mouth to the suction port of the case, and setting the inner diameter of the case and the inner diameter of the straight small-diameter section of the bell mouth into a fixed relation. CONSTITUTION:A thin cylinder 6 has an outer diameter smaller than the inner diameter if a case 1 and the outer diameter of a rotor blade 5, and a space S1 is formed between the case 1 and the thin cylinder 6. A bell mouth 8 has a flared shape, a small-diameter section 8b is formed into a straight pipe shape smaller than the inner diameter of the thin cylinder 6, and a space S2 is formed between the small-diameter section 8b and the thin cylinder 6. The inner diameter D1 of the case 1 and the inner diameter D2 of the small-diameter section 8b are set into a relation 0.5 D1<=D2<=0.8 D1. The air flow W1 in the case 1 partially becomes a back flow W2 at a position X near the tip section on the suction side of the rotor blade 5, but it flows through the space S1 and the space S2 and is merged with a main flow W1, the back flow 2 is recovered, and the air flow is not reduced. The main flow W1 and the back flow W2 are separated, the occurrence of an eddy is suppressed, and noise is reduced.

Kamaya Shiyuuji

Papers

Axial flow turbine