| 摘要 |
PURPOSE:To aim at noise reduction in the title device for an automobile by gradually increasing the width of a side wall within the range of the predetermined angle of a scroll casing toward a discharge port so as to form an inclined top wall, and arranging first and second suction ports at the predetermined positions of the inclined top wall. CONSTITUTION:The shaft-widthwise dimension B of a side wall 16, which is positioned within the range of a predetermined angle theta (about 180 deg.-270 deg.) at the substantial central portion of a winding angle range from the nose portion 14 of a scroll casing 1 to a discharge port, is gradually increased from B1 to B2, and then, a top wall 1a is formed on an inclined top wall 7. And, a first inside air suction port 4 is arranged on a flat top wall, which is closer to the nose portion 14 than the inclined top wall 7, while a second inside air suction port 5 is arranged on the flat portion which is closer to the discharge port side than the inclined top wall 7. In addition, the longitudinal length of a first damper 9 is set longer than that of a second damper 10, thereby preventing the interference of the second damper 10 with inclined top wall 7. This constitution reduces any noise. |
