US4385250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronous motor having gradual edge effect
Assignee: Parker Intangibles LLC
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Filing: 1981-01-12
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Granted: 1983-05-24
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Expires: 2001-01-12
Abstract
Abstract A synchronous motor has a gradual edge effect as rotor teeth align with stator teeth by varying the width of the stator teeth. The edges of uniformly spaced rotor teeth of equal width will align with edges of the widest stator teeth before aligning with the edges of the narrower stator teeth. The change in torque associated with edge alignment of the rotor and stator teeth is spread in time and position with less compounding of the changing torque. More uniform torque and smoother, quieter motor operation results.
Inventors
- 👤 Ross D. Welburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:54
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/10; H02K19/103
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
98 words
A synchronous motor comprising a stator portion having a plurality of poles with each pole having a surface including a first plurality of equally spaced teeth, the width of said teeth being wider in the center of each pole than at the edges of each pole, and a rotor portion rotatably positioned within said stator portion, said rotor portion having a surface with a second plurality of equally spaced teeth, said second plurality of teeth being of equal width and positioned to align with said first plurality of teeth as said rotor portion rotates in said stator portion.
Claim 2
Dependent Claim
98 words
A synchronous motor comprising a stator portion having a plurality of poles with each pole having a surface including a first plurality of equally spaced teeth, the width of said teeth being wider in the center of each pole than at the edges of each pole, and a rotor portion rotatably positioned within said stator portion, said rotor portion having a surface with a second plurality of equally spaced teeth, said second plurality of teeth being of equal width and positioned to align with said first plurality of teeth as said rotor portion rotates in said stator portion.
Claim 3
Dependent Claim
26 words
A synchronous motor as defined by claim 1 wherein the number of said second plurality of teeth equals the number of teeth of said stator portion.
Claim 4
Dependent Claim
35 words
A synchronous motor as defined by claim 1 or 2 wherein said stator portion includes a plurality of stacked laminations and a plurality of coils wound on said stacked laminations defining said plurality of poles.
Claim 5
Dependent Claim
18 words
A synchronous motor as defined by claim 3 wherein said rotor portion includes a plurality of stacked laminations.
Claim 6
Dependent Claim
93 words
A synchronous motor comprising an annular stator having a plurality of inwardly extending poles with each pole face defined by an undulating surface with a first plurality of equally spaced teeth, a cylindrical rotor having a periphery defined by an undulating surface with a second plurality of uniformly spaced teeth, said first plurality of teeth being disposed whereby edge alignment of said second plurality of teeth with said first plurality of teeth as said rotor rotates within said stator occurs first with teeth of said first plurality near the center of a pole.
Claim 7
Dependent Claim
93 words
A synchronous motor comprising an annular stator having a plurality of inwardly extending poles with each pole face defined by an undulating surface with a first plurality of equally spaced teeth, a cylindrical rotor having a periphery defined by an undulating surface with a second plurality of uniformly spaced teeth, said first plurality of teeth being disposed whereby edge alignment of said second plurality of teeth with said first plurality of teeth as said rotor rotates within said stator occurs first with teeth of said first plurality near the center of a pole.
Claim 8
Dependent Claim
31 words
A synchronous motor as defined by claim 5 wherein in said first plurality of teeth, near the center of a pole are wider than teeth near the edge of a pole.
Claim 9
Dependent Claim
18 words
A synchronous motor as defined by claim 6 wherein said second plurality of teeth are of uniform width.
Claim 10
Dependent Claim
25 words
A synchronous motor as defined by claim 7 wherein the number of teeth of said stator equals the number of said second plurality of teeth.
Claim 11
Dependent Claim
107 words
In a synchronous motor having an annular stator with a plurality of inwardly extending poles and with the pole faces having a first plurality of equally spaced teeth and a cylindrical rotor having a peripheral surface with a second plurality of equally spaced teeth, a method of operating said motor to reduce shaft vibration comprising the step of disposing said first plurality of teeth with respect to said second plurality of teeth whereby edge alignment of said first plurality of teeth and said plurality of teeth as said rotor rotates within said stator occurs first with teeth of said first plurality near the center of a pole.
Claim 12
Dependent Claim
107 words
In a synchronous motor having an annular stator with a plurality of inwardly extending poles and with the pole faces having a first plurality of equally spaced teeth and a cylindrical rotor having a peripheral surface with a second plurality of equally spaced teeth, a method of operating said motor to reduce shaft vibration comprising the step of disposing said first plurality of teeth with respect to said second plurality of teeth whereby edge alignment of said first plurality of teeth and said plurality of teeth as said rotor rotates within said stator occurs first with teeth of said first plurality near the center of a pole.
Claim 13
Dependent Claim
57 words
The method of operating a synchronous motor to reduce shaft vibration as defined by claim 9 wherein said step of disposing said first plurality of teeth with respect to said second plurality of teeth includes providing teeth of said first plurality which are wider near the center of a pole than at the edge of a pole.
References Cited (Backward Citations)
US4112319A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-23 | 1986-11-22 | 1987-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-23 | 1990-11-22 | 1991-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-23 | 1994-11-22 | 1995-05-24 | $7700.00 | Window Closed / Lapsed |