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US 3,975,117 AGranted
Pump and motor unit with inducer at one end and centrifugal impeller at opposite end of the motor
OwnerJames Coolidge Carterinventor
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OwnerJames Coolidge Carterinventor
Estimating the term…
Motor driven inducer equipped centrifugal pumps have the inducer and centrifugal pump impellers mounted on a motor shaft on opposite ends of the motor so that the inducer will not create prerotation in the impeller entrance permitting both the inducer and the impeller to operate independently and produce a head which is the sum of the two individual heads produced by the inducer and the impeller. The heretofore required relationship between the inducer outer diameter and the impeller inner diameter is eliminated and inducer sizes may be varied for best efficiency. Pumpage is vented to the motor through a hollow motor shaft to cool the motor and lubricate the bearings. Multi-staging of the pump is simplified with standard parts being stacked to produce the desired number of stages and, in the multi-stage embodiment, the second stage impeller is subjected to an upward thrust by the pumpage from the first stage to balance inducer thrust loads on the bearings with opposite impeller thrust loads.
A pump and motor unit with an inlet at one end and an outlet at the opposite end which comprises an axial flow inducer impeller in said inlet of the unit, a centrifugal impeller in said unit adjacent said outlet, a motor between said axial flow inducer and said centrifugal impeller, said centrifugal impeller having an inlet side facing the inducer impeller and receiving fluid directly from the inducer impeller for discharge to said outlet, a motor shaft extending beyond both ends of the motor of said unit supporting said inducer impeller at one end and supporting the centrifugal impeller at the opposite end, said centrifugal impeller exerting an axial thrust load on said motor shaft opposing the axial thrust load of the inducer impeller, and means in said unit providing a direct continuous substantially axial flow path from the inducer impeller to the centrifugal impeller.
A submersible electric motor driven inducer equipped centrifugal pump adapted for pumping cryogenic fluids and fluids at their boiling points which comprises a casing adapted to be mounted upright having a bottom inlet and a top outlet, an electric motor housing in said casing in spaced concentric relation therewith, a motor shaft projecting beyond both ends of the motor housing, an axial flow inducer impeller mounted on the bottom end of the motor shaft in said bottom inlet of the casing, a centrifugal impeller mounted on the top end of said shaft above the motor housing having an inlet facing the discharge side of the inducer impeller, said motor housing and said casing providing therebetween a direct flow path between the discharge side of the inducer impeller and the inlet side of the centrifugal impeller free from turns which reverse flow in a direction toward the inducer impeller, means providing a flow path from the discharge side of said centrifugal impeller to said top outlet of the casing, means bleeding pumpage from the discharge side of the centrifugal impeller to the interior of the motor housing for cooling the motor, means returning the bled-off pumpage from the interior of the motor housing back to the discharge side of the inducer impeller, and said centrifugal impeller exerting an axial thrust load on said motor shaft opposing the axial thrust load of the inducer impeller.
Dependencies are inferred from the claim text.