Patent US3746900A successfully refreshed from Google Patents.
US3746900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronous motor with improved starting characteristics
Assignee: AMF Inc
•
Filing: 1972-03-01
•
Granted: 1973-07-17
•
Expires: 1992-03-01
Abstract
Abstract A synchronous A.C. motor having two sets of stator poles disposed in circular spaced alternate series, a rotor disposed therein with alternate pole areas equal in number to the stator poles which provide two paths for rotor flux when the motor is quiescent, and the stator poles being made such that the normally lesser dominent flux path is dominent causing the rotor to assume a desired starting position while not causing imbalance when the motor is operated.
Inventors
- 👤 E Morley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:02
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
In a synchronous A.C. motor, thE combination comprising a permanent magnet rotor having a plurality of pole areas at its periphery each being of the opposite polarity to the adjacent pole areas, a stator having a pair of magnetically coupled pole pieces each one with a plurality of spaced stator poles equal in length and width, the stator poles of each of said pole pieces extending into spaces between the stator poles of said other pole piece and the stator poles of the two pole pieces being arranged in a circular series of equally spaced stator poles encircling said rotor and being equal in number to the rotor pole areas, said stator poles lapping the periphery of said rotor to provide paths for rotor flux, the stator poles of one of said pole pieces lapping the periphery of said rotor by a shorter extent than the stator poles of the other one of said pole pieces, thereby providing means for causing said rotor to assume a predetermined starting position when the motor is quiescent.
Claim 2
Dependent Claim
174 words
In a synchronous A.C. motor, thE combination comprising a permanent magnet rotor having a plurality of pole areas at its periphery each being of the opposite polarity to the adjacent pole areas, a stator having a pair of magnetically coupled pole pieces each one with a plurality of spaced stator poles equal in length and width, the stator poles of each of said pole pieces extending into spaces between the stator poles of said other pole piece and the stator poles of the two pole pieces being arranged in a circular series of equally spaced stator poles encircling said rotor and being equal in number to the rotor pole areas, said stator poles lapping the periphery of said rotor to provide paths for rotor flux, the stator poles of one of said pole pieces lapping the periphery of said rotor by a shorter extent than the stator poles of the other one of said pole pieces, thereby providing means for causing said rotor to assume a predetermined starting position when the motor is quiescent.
Claim 3
Dependent Claim
20 words
A synchronous A.C. motor in accordance with claim 1, and said rotor being a disc of ceramic permanent magnet material.
Claim 4
Dependent Claim
36 words
A synchronous A.C. motor in accordance with claim 1, and said rotor comprising a rotor cup having a peripheral flange, and a permanent magnet of deformable material disposed in said cup substantially against the flange thereof.
Claim 5
Dependent Claim
29 words
A synchronous A.C. motor in accordance with claim 1, and said rotor comprising a rotor cup having a peripheral flange, and an annular permanent magnet encircling said peripheral flange.
Claim 6
Dependent Claim
30 words
A synchronous A.C. motor in accordance with claim 4, and a permanent magnet of deformable material being wrapped around and connected to said peripheral flange providing said annular permanent magnet.
Claim 7
Dependent Claim
53 words
A synchronous A.C. motor in accordance with claim 1 wherein said stator further having a core of magnetic material and a coil encircling said core, and said pole pieces being connected to opposite ends of said core with all of said stator poles extending in the same axial direction from said pole pieces.
Claim 8
Dependent Claim
58 words
A synchronous A.C. motor in accordance with claim 1 wherein said motor having a casing of magnetic material and an annular coil disposed in said casing, said pole pieces being disposed on opposite sides of said coil, and said stator poles of each pole piece being disposed within said coil and extending axially toward the other pole piece.
Claim 9
Dependent Claim
28 words
A synchronous A.C. motor in accordance with claim 3 wherein said case has a cover formed to provide one of said pole pieces and the stator poles thereof.
References Cited (Backward Citations)
GB841357A
Cited
US3092743A
Cited
US3231770A
Cited
US3253169A
Cited
US3302046A
Cited
US3535571A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |