Centrifugal vacuum pump for brake booster of hybrid vehicle, has sleeve shaft which comprises several holes through which inner portion of sleeve shaft communicates with air flow channels formed in centrifugal impellers

摘要

The vacuum pump has a housing (1) and centrifugal impellers (5-7) which are rotatably mounted in the housing by a sleeve shaft (2), and are provided with several radially extending air flow channels. The housing comprises suction line (12) at the radial inner end and air outlets (16,17) at the radial outer ends, which are in flow communication with each other. The suction line communicates with an inner portion (10) of the sleeve shaft. The sleeve shaft comprises several holes (9) through which the inner portion of sleeve shaft communicates with air flow channels. An independent claim is included for method for generating low pressure by centrifugal impellers.