US3885890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic pumps
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1973-04-02
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Granted: 1975-05-27
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Expires: 1993-04-02
Abstract
Abstract The present specification describes and claims an electromagnetic pump suitable for use in pumping molten sodium. The pump comprises a central cylindrical core arranged coaxially in a bore within a pump casing, the surface of the core and the wall of the bore defining an annular passage therebetween. A three start helical winding is arranged coaxially with said central core, the free ends of one end of the winding being connectible to a three-phase electricity supply to thus produce an electromagnetic field within the annular passage which field can move the molten sodium along said annular passage.
Inventors
- 👤 Daniel Fraser Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:47
CPC Classifications
H; H02; H02K; H02K44/00; H02K44/02; H02K44/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
130 words
An electromagnetic pump comprising a cylindrical iron core co-axially arranged within an iron casing to bound an annular flow duct for liquid metal, the core being of laminated form and having three equally spaced, external helical slots and three equally spaced helical slits, the slits being in opposite rotational direction to the slots and intersecting the slots at right angles thereto, the slots being lined with electrically insulating material and housing windings adapted for connection at one end to a three phase electricity supply and joined together by a star point connection at the other end, the windings each comprising a stack of helically wound copper laminations and having coatings of insulating material on the outer circumferential surfaces, and a closely fitting stainless steel sheath for the core and windings.
Claim 2
Dependent Claim
130 words
An electromagnetic pump comprising a cylindrical iron core co-axially arranged within an iron casing to bound an annular flow duct for liquid metal, the core being of laminated form and having three equally spaced, external helical slots and three equally spaced helical slits, the slits being in opposite rotational direction to the slots and intersecting the slots at right angles thereto, the slots being lined with electrically insulating material and housing windings adapted for connection at one end to a three phase electricity supply and joined together by a star point connection at the other end, the windings each comprising a stack of helically wound copper laminations and having coatings of insulating material on the outer circumferential surfaces, and a closely fitting stainless steel sheath for the core and windings.
Claim 3
Dependent Claim
26 words
An electromagnetic pump according to claim 1 wherein the inner surface of the casing has elongate ribs extending parallel to the longitudinal axis of the casing.
Claim 4
Dependent Claim
37 words
An electRomagnetic pump according to claim 1 wherein the slots have square cross-section and helical pitch equal to the core diameter, the spacing of the slots being equal to one half of the width of the slots.
Claim 5
Dependent Claim
20 words
An electromagnetic pump according to claim 1 wherein the core has a central flow duct extending along the longitudinal axis.
References Cited (Backward Citations)
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US2905089A
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US3147711A
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US3275859A
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US3187672A
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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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |