Patent US880347A successfully refreshed from Google Patents.
Patent US3571637A successfully refreshed from Google Patents.
US3571637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet excited electric machines
Assignee: ESAB AB
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Filing: 1969-12-09
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Granted: 1971-03-23
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Expires: 1989-12-09
Abstract
Abstract A dynamoelectric machine having a stator carrying the winding of the machine and a rotor comprising an annular, axially magnetized permanent magnet and a pair of pole units, each of which comprises a hub portion engaging one end face of the permanent magnet and a group of pole projections extending substantially towards the hub portion of the other pole unit, the pole projections of both pole units being equally spaced and interspaced with each other, said permanent magnet being surrounded by a sheath of nonmagnetic metallic material cast around the outer, cylindrical surface of the permanent magnet, said sheath filling the space between said pole projections and the permanent magnet as well as the spaces between the pole projections.
Inventors
- 👤 Christian Johannes Henningsen
- 👤 Karl Axel Karlsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:01
CPC Classifications
H; H02; H02K; H02K21/00; H02K21/02; H02K21/021; H02K21/028; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/2713; H02K21/12; H02K21/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
231 words
A rotary electric machine, particularly a welding generator, comprising a stator, a winding carried by said stator, and a rotor, said rotor comprising a shaft, an annular, axially magnetized permanent magnet coaxially supported by said shaft, a pair of pole units, each of which comprises a hub portion engaging one end face of said annular permanent magnet and a group of pole projections extending substantially axially from the rim of said hub portion towards the other hub portion while radially spaced from said annular permanent magnet, the pole projections of one group extending between the pole projections of the other group, a sheath of nonmagnetic metallic material cast around the outer surface of the annular permanent magnet, said sheath filling the space between said pole projections and the permanent magnet as well as the spaces between said groups of pole projections, the resulting composite body presenting a cylindrical outer surface to the air gap of the machine, and a rigid annular prestressing member of nonmagnetic material concentric with said annular permanent magnet and embedded within said sheath, said annular prestressing member being at its outer periphery force fitted into a step provided in each of said pole projections, the force fit being tight enough to maintain the engagement against the action of the centrifugal force and the magnetic force to which the pole projections are subjected during operation of the machine.
Claim 2
Dependent Claim
231 words
A rotary electric machine, particularly a welding generator, comprising a stator, a winding carried by said stator, and a rotor, said rotor comprising a shaft, an annular, axially magnetized permanent magnet coaxially supported by said shaft, a pair of pole units, each of which comprises a hub portion engaging one end face of said annular permanent magnet and a group of pole projections extending substantially axially from the rim of said hub portion towards the other hub portion while radially spaced from said annular permanent magnet, the pole projections of one group extending between the pole projections of the other group, a sheath of nonmagnetic metallic material cast around the outer surface of the annular permanent magnet, said sheath filling the space between said pole projections and the permanent magnet as well as the spaces between said groups of pole projections, the resulting composite body presenting a cylindrical outer surface to the air gap of the machine, and a rigid annular prestressing member of nonmagnetic material concentric with said annular permanent magnet and embedded within said sheath, said annular prestressing member being at its outer periphery force fitted into a step provided in each of said pole projections, the force fit being tight enough to maintain the engagement against the action of the centrifugal force and the magnetic force to which the pole projections are subjected during operation of the machine.
Claim 3
Dependent Claim
198 words
A rotary electric machine, particularly a welding generator, comprising a stator, a winding carried by said stator, and a rotor, said rotor comprising a shaft of a magnetic material, an annular, axially magnetized permanent magnetic coaxially supported by said shaft, a pair of pole units, each of which comprises a hub portion engaging one end face of said annular permanent magnet anD a group of pole projections extending substantially axially from the rim of said hub portion towards the other hub portion while radially spaced from said annular permanent magnet, the pole projections of one group extending between the pole projections of the other group, one of said hub portions being radially spaced from said shaft to provide a radial gap, a sheath of nonmagnetic metallic material cast around the outer surface of the annular permanent magnet, said sheath filling the space between said pole projections and the permanent magnet as well as the spaces between said groups of pole projections, the resulting composite body presenting a cylindrical outer surface to the air gap of the machine, an annular magnetic member axially displaceable in said gap, and means for adjusting the axial position of said annular magnetic member.
Claim 4
Dependent Claim
198 words
A rotary electric machine, particularly a welding generator, comprising a stator, a winding carried by said stator, and a rotor, said rotor comprising a shaft of a magnetic material, an annular, axially magnetized permanent magnetic coaxially supported by said shaft, a pair of pole units, each of which comprises a hub portion engaging one end face of said annular permanent magnet anD a group of pole projections extending substantially axially from the rim of said hub portion towards the other hub portion while radially spaced from said annular permanent magnet, the pole projections of one group extending between the pole projections of the other group, one of said hub portions being radially spaced from said shaft to provide a radial gap, a sheath of nonmagnetic metallic material cast around the outer surface of the annular permanent magnet, said sheath filling the space between said pole projections and the permanent magnet as well as the spaces between said groups of pole projections, the resulting composite body presenting a cylindrical outer surface to the air gap of the machine, an annular magnetic member axially displaceable in said gap, and means for adjusting the axial position of said annular magnetic member.
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) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |