US3689787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet motor having pole shoe rotor with laminations to retard eddy currents
Assignee: Individual
•
Filing: 1971-03-22
•
Granted: 1972-09-05
•
Expires: 1991-03-22
Abstract
Abstract A permanent magnet motor particularly adapted as a stepper motor. It is of a low inertia type having an axially polarized permanent magnet and wherein the feature of an axial air gap between a rotor and the magnet is embodied. The rotor provides the axial air gap. It is in the form of a low reluctance body having a peripheral part of laminated construction to improve pulsed stepping operation by minimizing deleterious effects caused by eddy currents.
Inventors
- 👤 Simon Saretzky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:21
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/10; H02K37/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
85 words
A rotor and stator assembly comprising a laminated core assembly having poles with windings thereon, a shaft having a cup-shaped rotor thereon, a cylindrical permanent magnet secured to the housing and extending into said cup-shaped rotor, said rotor having a part positioned to rotate adjacent surfaces of the stator poles and adjacent said permanent magnet, the rotor having a body part of material offering a low reluctance path, the body part being cylindrical and having ring-shaped laminations secured around the periphery thereof and coextensive therewith.
Claim 2
Dependent Claim
85 words
A rotor and stator assembly comprising a laminated core assembly having poles with windings thereon, a shaft having a cup-shaped rotor thereon, a cylindrical permanent magnet secured to the housing and extending into said cup-shaped rotor, said rotor having a part positioned to rotate adjacent surfaces of the stator poles and adjacent said permanent magnet, the rotor having a body part of material offering a low reluctance path, the body part being cylindrical and having ring-shaped laminations secured around the periphery thereof and coextensive therewith.
Claim 3
Dependent Claim
30 words
A structure as in claim 1 wherein said magnet is axially magnetized and positioned to provide a steady state field through itself the rotor and a part of a housing.
Claim 4
Dependent Claim
37 words
A structure as in claim 1 wherein the rotor has a skirt concentrically positioned between the stator pole faces and the permanent magnet, providing an axial air gap between an end of the magnet and the rotor.
Claim 5
Dependent Claim
28 words
A structure as in claim 1 wherein the said permanent magnet is displaced axially from the stator poles, and a housing having a part supporting the permanent magnet.
Claim 6
Dependent Claim
28 words
A structure as in claim 1 wherein said pole faces have teeth formed therein and said rotor has peripheral teeth rotatable adjacent the teeth on the pole faces.
Claim 7
Dependent Claim
16 words
A structure as in claim 4 wherein said permanent magnet is cantilever mounted from said housing.
Claim 8
Dependent Claim
82 words
A rotor and stator assembly comprising a laminated core assembly having poles with windings thereon, a shaft having a cup-shaped rotor thereon, a cylindrical stator member secured to the housing and extending into said cup-shaped rotor, said rotor having a part positioned to rotate between said poles and said cylindrical stator member, said rotor having a body part of material offering a low reluctance path and the peripheral part of the rotor including laminations positioned around the periphery thereof and coextensive therewith.
Claim 9
Dependent Claim
82 words
A rotor and stator assembly comprising a laminated core assembly having poles with windings thereon, a shaft having a cup-shaped rotor thereon, a cylindrical stator member secured to the housing and extending into said cup-shaped rotor, said rotor having a part positioned to rotate between said poles and said cylindrical stator member, said rotor having a body part of material offering a low reluctance path and the peripheral part of the rotor including laminations positioned around the periphery thereof and coextensive therewith.
References Cited (Backward Citations)
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Cited
US3469124A
Cited
US3549923A
Cited
US3500081A
Cited
US3519859A
Cited
US3532916A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |