Abstract: An improvement in an electrical air pump having a housing with a pump mechanism at one end and an electric motor at the other end. The pump mechanism has at least one lightweight pump impeller made of plastic whose hub is press-fit on a shaft of the electric motor. The hub is provided with a plurality of grooves distributed around a bore in the hub which receives the motor shaft. The grooves form spaces between an inner surface of the hub and an outer surface of the shaft and the spaces are filled with an adhesive to bond the hub to the shaft. The grooves extend longitudinally or spirally along the entire length of the hub. The grooves are relatively shallow and have a depth of approximately 0.05 mm.

Abstract: An electrical air pump adapted for being periodically turned on and off and reversed in pumping direction. The air pump includes an electric motor adapted for electronic control and an air pump section joined by a housing as a common system. The housing has a cylindrical wall defining a first chamber in which the stator system is received and a scaling cover is engaged with the housing to seal the first chamber. The air pump section includes a pump cover sealingly engaged with the housing and defining therewith a second chamber, the rotor being of bell shape and rotatably supported in the second chamber on a pin secured in the housing and in the pump cover. The rotor is disposed with slight clearance adjacent to an end wall of the housing and the rotor projects radially beyond the cylindrical wall. The rotor has a collar and a plurality of pumping blades extending radially from the collar into an annular pumping channel of the second chamber.

Abstract: A method and apparatus for periodically air-washing a charcoal canister and for testing leak-tightness of a closed fuel supply system of an internal combustion engine in which a reversible electric air pump is installed in a line connecting the fuel system and the canister to the intake manifold of the engine upstream of the choke valve. In one direction of operation of the pump, ambient air is sucked through the canister and fed to the intake manifold to wash the canister and in the other direction of operation of the pump, air is pumped from above the choke valve in the intake manifold to the fuel system to pressurize the system to check leak-tightness thereof. When the engine is turned off, the pump is shut off and the fuel supply system is connected to the canister.

Abstract: 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.

Abstract: An electrically driven air pump having a pump mechanism in a first section of a housing and an electric motor in a second section of the housing in driving engagement with the pump mechanism. First and second end covers are sealingly secured on the housing. The electric motor is supported by elastomer rings in the housing. The pump mechanism has two axially spaced rotor wheels secured on the drive shaft of the motor and a stator wheel between the rotor wheels. The electric motor is balanced, in situ, in its mounted state by adjusting that one of the rotor wheels which is exposed in the housing prior to installation of the end cover on the first section of the housing. After the motor is balanced, the end cover is press fit on the housing and stator wheel to form air-tight, friction fit seal joints therebetween in which the engaged parts which are deformed elastically or plastically.

Abstract: An electrically driven air pump having a pump mechanism in a first section of a housing and an electric motor in a second section of the housing in driving engagement with the pump mechanism. First and second end covers are sealingly secured on the housing. The electric motor is supported by elastomer rings in the housing. The pump mechanism has a rotor wheel driven by the motor and a stator wheel adjacent to the rotor wheel. A first lock joint is formed between the first cover and both the stator wheel and the housing and a second lock joint is formed between the second cover and the housing. The covers, stator wheel and housing are made of plastic material and the lock joints are formed by air-tight, friction-fit between the engaged parts which are deformed elastically or plastically.

Abstract: An electrically driven air pump having a housing, a pump mechanism in the housing and an electric motor in the housing connected in driving relation to the pump mechanism. Two spaced elastic supports support the electric motor from the housing at opposite ends of the motor. An air passage in the housing provides a flow of air past the electric motor to the pump mechanism. The air passage includes a suction nozzle supported by one of the elastic supports for supplying air to an inlet collar of a pump impeller of the pump mechanism. The suction nozzle projects into the collar for supply of the air from the electric motor to the pump mechanism.