US3553509A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct-current motor energized by permanent magnets
Assignee: US Philips Corp
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Filing: 1969-01-21
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Granted: 1971-01-05
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Expires: 1989-01-21
Abstract
Abstract DC motor including a tubular stator housing having a pair of curved permanent magnets mounted on the inner surface thereof. A pair of magnetic pole pieces each comprising a segment of a cylinder are concentrically mounted in contact with the inner surface of the magnets. The outer circumference of the pole piece is at least 1 1/2 times its inner surface thereby concentrating the magnetic flux and reducing the stray flux.
Inventors
- 👤 Jean Frantz Felix Schellekens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:23
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/02; H02K23/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
140 words
A direct current motor comprising a tubular stator housing and a rotatable rotor member concentrically arranged within said stator housing, fiRst and second permanent magnets each having the configuration of a hollow tube sector and concentrically mounted with their outer walls engaging the stator housing, first and second magnetic pole pieces each comprising a longitudinal segment of a cylinder having nonradial sidewalls defining the circumferential limits of the segment so that the outer circumferential surface of the segment is at least 1 1/2 times longer than its inner surface, and means for concentrically mounting said first and second segments with their outer surfaces in contact with the inner surfaces of said first and second magnets, respectively, and with their inner surfaces facing said rotor to define an air gap therewith thereby to concentrate the magnetic flux within a given area.
Claim 2
Dependent Claim
140 words
A direct current motor comprising a tubular stator housing and a rotatable rotor member concentrically arranged within said stator housing, fiRst and second permanent magnets each having the configuration of a hollow tube sector and concentrically mounted with their outer walls engaging the stator housing, first and second magnetic pole pieces each comprising a longitudinal segment of a cylinder having nonradial sidewalls defining the circumferential limits of the segment so that the outer circumferential surface of the segment is at least 1 1/2 times longer than its inner surface, and means for concentrically mounting said first and second segments with their outer surfaces in contact with the inner surfaces of said first and second magnets, respectively, and with their inner surfaces facing said rotor to define an air gap therewith thereby to concentrate the magnetic flux within a given area.
Claim 3
Dependent Claim
45 words
A motor as claimed in claim 1 wherein each of said pole pieces are shaped to provide a pair of flat longitudinally extending surfaces, and said mounting means comprises a pair of longitudinally mounted rods for each pole piece and bearing against said flat surfaces.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |