Impeller mounting for electrically driven air pump to reduce vibration

摘要

An electrically driven air pump having a housing containing a pump unit driven from a shaft of an electric motor, the pump unit including two impellers made of plastic having hubs which are press-fit on the shaft of the electric motor. A collar is also press-fit on the shaft and abutting against the hub of one impeller on a side thereof facing the electric motor, and a lock ring made of metal is press-fit on the shaft and abuts against the hub of the other impeller on a side thereof facing away from the electric motor thereby to clamp the impellers between the collar and the lock ring. The lock ring and the hub of the adjoining impeller are formed at their mutually abutting surfaces with a tooth and groove arrangement to prevent relative rotary movement therebetween. A similar tooth and groove arrangement can be provided between the abutting surfaces of the impellers and between the abutting surfaces of the collar and the adjoining impeller.