| 摘要 |
PURPOSE:To reduce the contact force at a sealed end surface by providing a piston ring between a collar and a plate so as to reduce a pressure variation range in an air chamber. CONSTITUTION:An annular groove 19 is provided on the periphery of a collar 16 near a compressor impeller 15, a step is provided on the bore surface of a plate 4 opposite to the groove 19, and a piston ring 20 is provided in the annular groove 19. Accordingly, the pressure difference between an air chamber 12 and an oil chamber 11 applied to a sealed end surface 10 is decreased, thereby reducing the friction at the sealed end surface and also reducing the rotational resistance. |
