US3918852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump
Assignee: Individual
•
Filing: 1974-06-24
•
Granted: 1975-11-11
•
Expires: 1994-06-24
Abstract
Abstract Overloading and failures of the lower bearings in submersible electric motor driven centrifugal pumps having inducer impellers ahead of the main centrifugal pumping impeller are avoided by transferring the inducer thrust from the lower bearing to an upper bearing which has ample reserve capacity to accept the added thrust load without redesign of existing pump and bearing assemblies. The transfer of the inducer thrust from the lower to the upper bearing is accomplished by slidably keying the inducer impeller on a hollow motor driven main pump shaft and supporting the inducer impeller on a second shaft extending through the hollow pump shaft and suspended from a top main shaft bearing.
Inventors
- 👤 James Coolidge Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:48
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/04; F04D29/041; F04D29/043; F04D29/046; F04D29/049; F04D7/00; F04D7/02; F04D7/06; F04D9/00; F04D9/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
97 words
In a pump and motor unit having a main pump impeller and an inducer impeller ahead of the main pump impeller driven by the same motor from a hollow main drive shaft supported in axially spaced bearings in the unit, one of which is adjacent the main pump impeller and the other of which is remote from the main pump impeller, the improvement which comprises a second shaft extending through the hollow main shaft suspended from the remote bearing and supporting the inducer impeller to relieve the other bearing from thrust loads developed by the inducer impeller.
Claim 2
Dependent Claim
97 words
In a pump and motor unit having a main pump impeller and an inducer impeller ahead of the main pump impeller driven by the same motor from a hollow main drive shaft supported in axially spaced bearings in the unit, one of which is adjacent the main pump impeller and the other of which is remote from the main pump impeller, the improvement which comprises a second shaft extending through the hollow main shaft suspended from the remote bearing and supporting the inducer impeller to relieve the other bearing from thrust loads developed by the inducer impeller.
Claim 3
Dependent Claim
27 words
The improvement of claim 1 wherein the inducer impeller is slidably keyed on the hollow main shaft and is free to slide axially on the main shaft.
Claim 4
Dependent Claim
18 words
The improvement of claim 1 wherein the bearings are respectively at the bottom and top of the motor.
Claim 5
Dependent Claim
11 words
The improvement of claim 1 wherein the bearings are ball bearings.
Claim 6
Dependent Claim
122 words
A submersible electric motor driven centrifugal pump adapted for pumping cryogenic fluids and fluids at their boiling points which comprises a casing adapted to be mounted in the bottom of a tank and having a bottom inlet and a top outlet, an electric motor in the casing, a hollow shaft driven by said motor, a centrifugal impeller mounted on said shaft for co-rotation therewith receivIng fluid from said inlet and discharging fluid through the casing to the top outlet, a second shaft extending through said hollow shaft, an inducer impeller slidably keyed on said hollow shaft in said pump inlet, means suspending said second shaft from the top of said casing, and means axially supporting said inducer impeller on said second shaft.
Claim 7
Dependent Claim
122 words
A submersible electric motor driven centrifugal pump adapted for pumping cryogenic fluids and fluids at their boiling points which comprises a casing adapted to be mounted in the bottom of a tank and having a bottom inlet and a top outlet, an electric motor in the casing, a hollow shaft driven by said motor, a centrifugal impeller mounted on said shaft for co-rotation therewith receivIng fluid from said inlet and discharging fluid through the casing to the top outlet, a second shaft extending through said hollow shaft, an inducer impeller slidably keyed on said hollow shaft in said pump inlet, means suspending said second shaft from the top of said casing, and means axially supporting said inducer impeller on said second shaft.
Claim 8
Dependent Claim
35 words
The pump of claim 4 wherein the casing has a main antifriction bearing supporting the hollow shaft radially and axially and a top antifriction bearing radially supporting said shaft and axially suspending said second shaft.
Claim 9
Dependent Claim
41 words
The pump of claim 4 including a first antifriction bearing radially and axially supporting the hollow shaft and a second antifriction bearing spaced from the first bearing also radially supporting the hollow shaft and radially and axially supporting the second shaft.
Claim 10
Dependent Claim
22 words
The pump of claim 4 wherein the second shaft is suspended from a top antifriction bearing in the top of the casing.
Claim 11
Dependent Claim
46 words
The pump of claim 4 wherein a ball bearing in the casing at bottom end of the motor carries thrust and radial loads of the hollow shaft and a second ball bearing in the casing at the top end of the motor suspends the second shaft.
Claim 12
Dependent Claim
42 words
The pump of claim 4 wherein the inducer impeller has a hub slidably keyed on the bottom end of the hollow shaft and four blades extend from the hub across the pump inlet to develop inlet head pressure for the centrifugal impeller.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |