Patent US6436138B1 successfully refreshed from Google Patents.
US4234293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Axial balancing system for motor driven pumps
Assignee: Dresser Industries Inc
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Filing: 1979-03-27
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Granted: 1980-11-18
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Expires: 1999-03-27
Abstract
Abstract The pump described is of the canned motor type generally used for handling caustic materials where the motor is integrated into the pump, but must be totally sealed therefrom. The pump rotor is mounted on a hollow shaft that is supported by bearings on a hollow mandrel which has one end secured to the pump housing and the other end secured to a lug projecting from a rear shaft support plate. The lug is hollow and is provided with a plurality of ports that provide fluid communication between the motor housing and the pump inlet through the hollow mandrel. The shaft is arranged, when moved axially by the thrust developed by the centrifugal pump to open and close the ports regulating flow therethrough and thereby exerting a force on the shaft to counteract the thrust force generated during pumping.
Inventors
- 👤 John R. Lightle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:56
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/04; F04D29/042; F04D13/00; F04D13/02; F04D13/06; F04D13/0606; F04D13/062; Y; Y10; Y10S; Y10S417/00; Y10S417/902
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
186 words
An improvement to an axial balancing system for a motor driven centrifugal pump including a pump and motor housing, a hollow mandrel having one end mounted in the pump housing, a hollow rotor shaft rotatable and axially movable on the mandrel, a bearing located near each end of the mandrel between the shaft and mandrel, said improvement comprising: a support plate located in the motor housing; a hollow lug projecting from said plate toward said mandrel, said lug having an outer diameter sized to movably receive the rotor shaft and an interior sized to fixedly receive the other end of the mandrel, and said lug having a plurality of ports therein providing fluid communication between the interior of the motor housing and the interior of the mandrel, said ports being located in positions to be covered and uncovered by the rotor shaft during axial movement thereof as axial thrust is generated by the pumping of fluid by the motor pump; and, said lug having an annular end face engageable with one of the bearings to limit the axial movement of the shaft toward said support plate.
Claim 2
Dependent Claim
186 words
An improvement to an axial balancing system for a motor driven centrifugal pump including a pump and motor housing, a hollow mandrel having one end mounted in the pump housing, a hollow rotor shaft rotatable and axially movable on the mandrel, a bearing located near each end of the mandrel between the shaft and mandrel, said improvement comprising: a support plate located in the motor housing; a hollow lug projecting from said plate toward said mandrel, said lug having an outer diameter sized to movably receive the rotor shaft and an interior sized to fixedly receive the other end of the mandrel, and said lug having a plurality of ports therein providing fluid communication between the interior of the motor housing and the interior of the mandrel, said ports being located in positions to be covered and uncovered by the rotor shaft during axial movement thereof as axial thrust is generated by the pumping of fluid by the motor pump; and, said lug having an annular end face engageable with one of the bearings to limit the axial movement of the shaft toward said support plate.
Claim 3
Dependent Claim
29 words
The improvement of claim 1 wherein the exterior of the end of the rotor shaft is bevelled to reduce pumping by the shaft and facilitate flow through said ports.
Claim 4
Dependent Claim
19 words
The improvement of claim 2 wherein the bearing adjacent said plate is enclosed within said mandrel, shaft and lug.
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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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |