Two-component impeller for e.g. centrifugal compressor used in fuel cell system, has blades in upstream and downstream sides, where trailing edges of upstream blades are offset from leading edges of downstream blades

摘要

The impeller (7) has a wheel unit that is formed with blades (18,19) in upstream side (9) and a downstream side (10), where number of blades in the upstream side is greater than number of blades in the downstream side. The upstream side of the wheel unit is provided with an internal thread for screwing on one end of a shaft for fastening the impeller on the shaft. The trailing edges (21) of the upstream blades are offset from leading edges (22) of the downstream blades.