Patent US4144475A successfully refreshed from Google Patents.
Patent US3597646A successfully refreshed from Google Patents.
US3597646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamoelectric machines
Assignee: Individual
•
Filing: 1970-01-26
•
Granted: 1971-08-03
•
Expires: 1990-01-26
Abstract
Abstract A reluctance motor has a rotor constructed of separate segments of magnetic material and a squirrel cage winding, the conductor bars of which are arranged so that the cross section of conductive material decreases from a maximum in the central regions of the segments to a minimum in the vicinity of the ends of the segments. For example there may be no bars in the gaps and wider bars or bars spaced more closely together in the central regions. Shallow central channels with at least the vestiges of separate slots may be provided, the slots serving to maintain the value of the direct axis leakage reactance of the rotor winding. Towards the segment ends the slot shapes may be varied to reduce leakage reactance and increase the resistance. In addition, the segments may be provided with tips extending circumferentially outwardly. Also, holes may be provided close to the bases of the winding slots to cause saturation of the magnetic material between the holes and the slots. Yet again flux barriers may be provided beneath the winding slots.
Inventors
- 👤 Peter John Lawrenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:02
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/10; H02K19/103; H02K19/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
107 words
A dynamoelectric machine of the reluctance type having a rotor comprising a plurality of circumferentially extending segments of magnetic material magnetically isolated from each other by intersegmental gaps, said segments having slots for a squirrel cage winding, and electrically conductive material in the form of bars lying in said slots and end rings connected to said bars wherein the bars are so shaped and positioned that the cross section of conductive material per unit are decreases from a maximum in the central regions of the segments to a minimum in the vicinity of the ends of the segments and no bars are positioned in the intersegmental gaps.
Claim 2
Dependent Claim
107 words
A dynamoelectric machine of the reluctance type having a rotor comprising a plurality of circumferentially extending segments of magnetic material magnetically isolated from each other by intersegmental gaps, said segments having slots for a squirrel cage winding, and electrically conductive material in the form of bars lying in said slots and end rings connected to said bars wherein the bars are so shaped and positioned that the cross section of conductive material per unit are decreases from a maximum in the central regions of the segments to a minimum in the vicinity of the ends of the segments and no bars are positioned in the intersegmental gaps.
Claim 3
Dependent Claim
34 words
The machine as claimed in claim 14 in which the center-to-center spacing between bars is nonuniform and the bars are closer together in the central regions of the segments than elsewhere in the segments.
Claim 4
Dependent Claim
37 words
The machine as claimed in claim 14 in which the center-to-center spacing of the bars is uniform and the bars in the central regions of the segments have a greater cross section than elsewhere In the segments.
Claim 5
Dependent Claim
32 words
The machine as claimed in claim 14 in which shallow peripheral channels filled with conductive material are provided in the central regions of the segments and vestigial slots depend from said channels.
Claim 6
Dependent Claim
31 words
The machine as claimed in claim 14 in which at least some of the segments have at least one end tip which extends circumferentially outwardly around the periphery of the rotor.
Claim 7
Dependent Claim
39 words
The machine as claimed in claim 5 in which, the segments are shaped to provide tips for the teeth of the winding slots and in which the said end tips have similar shapes to the tips of the teeth.
Claim 8
Dependent Claim
17 words
The machine as claimed in claim 14 in which different segments have different shapes to each other.
Claim 9
Dependent Claim
17 words
The machine as claimed in claim 7 in which alternate segments have different numbers of winding slots.
Claim 10
Dependent Claim
17 words
The machine as claimed in claim 7 in which different segments have different spans to each other.
Claim 11
Dependent Claim
56 words
The machine as claimed in claim 14 in which holes are provided in the segments positioned close to the bases of the winding slots so that the magnetic material between the holes and the slots saturates and together with the holes and winding slots act to constitute a barrier for magnetic flux along the quadrature axes.
Claim 12
Dependent Claim
38 words
The machine as claimed in claim 14 in which flux guides are provided positioned and shaped so as to maintain low reluctance paths for flux in a circumferential direction and to constitute nonmagnetic barriers for quadrature axis flux.
Claim 13
Dependent Claim
36 words
The machine as claimed in claim 11 in which the flux guides comprise closed circumferentially extending slots positioned beneath the main winding slots and extending in a direction generally parallel to the circumference of the rotor.
References Cited (Backward Citations)
US2733362A
Cited
US2939025A
Cited
US3157805A
Cited
US3154705A
Cited
US3243620A
Cited
US3448310A
Cited
US3493799A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |