Patent US3787744A successfully refreshed from Google Patents.
US3787744A
Expired / Lapsed
US
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Laminated iron core of rotary electric machines
Assignee: Hitachi Ltd
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Filing: 1972-07-11
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Granted: 1974-01-22
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Expires: 1992-07-11
Abstract
Abstract A newly developed laminated iron core is composed of number of unit segments, each of which is shaped such that one radial marginal periphery defines a half of a coil slot and the opposite periphery defines a half of a tooth between the two coil slots. Accordingly, when such segments are juxtaposed to form a layer of an annular iron core, a pair of the segments constitute a sector having an odd number (2n + 1) of coil slots, wherein n is the number of coil slots in a unit segment, whereas a pair of unit segments of ordinary type bears an even number of coil slots. Assembled iron cores each using either one of the type mentioned above bear a different number of coil slots suitable for different frequencies such as 50 Hertz and 60 Hertz but has the same outside and inside diameter and the same number of dovetail notches, thereby permitting two kinds of iron cores to be supported within a stator frame of single unified type.
Inventors
- 👤 K Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:19
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/12; H02K1/16; H02K1/18; H02K1/185
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
A laminated iron core for a rotary electric machine, comprising a plurality of unit segment plates disposed side by side to form annular layers laminated one on another axially with the joint of each segment plate in staggered relation to the joints of the other segment plates into a core of an annular shape, each of said segment plates being provided with supporting notches in the outer peripheral edge and coil slots in the inner peripheral edge thereof, one radial marginal side of each segment plate defining one-half of a coil slot and the opposite side thereof defining one-half of a tooth formed by the adjacent coil slots, whereby each segment plate may be supported by at least one key bar at a supporting notch.
Claim 2
Dependent Claim
125 words
A laminated iron core for a rotary electric machine, comprising a plurality of unit segment plates disposed side by side to form annular layers laminated one on another axially with the joint of each segment plate in staggered relation to the joints of the other segment plates into a core of an annular shape, each of said segment plates being provided with supporting notches in the outer peripheral edge and coil slots in the inner peripheral edge thereof, one radial marginal side of each segment plate defining one-half of a coil slot and the opposite side thereof defining one-half of a tooth formed by the adjacent coil slots, whereby each segment plate may be supported by at least one key bar at a supporting notch.
Claim 3
Dependent Claim
36 words
A laminated iron core for a rotary electric machine as claimed in claim 1, wherein the number of said supporting notches provided in said annular core is a multiple of the number of the coil slots.
Claim 4
Dependent Claim
35 words
A laminated iron core for a rotary electric machine as claimed in claim 1, wherein said core having a total of 12(n + 0.5) coils is supported by a stator frame having 12 key bars.
Claim 5
Dependent Claim
38 words
A laminated iron core as claimed in claim 1, wherein a plurality of annular layers composed of said segment plates and having a total of 42 coil slots are supported by a stator frame having 12 key bars.
Claim 6
Dependent Claim
53 words
A laminated iron core for a rotary electric machine as claimed in claim 2, wherein alternate segment plates are disposed upside down so that said half coil slot and said half tooth of adjacent segment plates are reversed to combine with the half coil slot and half tooth of the adjoining segment plate.
Claim 7
Dependent Claim
35 words
A laminated iron core for a rotary electric machine as claimed in claim 5, wherein said core having a total of 12(n + 0.5) coils is supported by a stator frame having 12 key bars.
Claim 8
Dependent Claim
38 words
A laminated iron core as claimed in claim 5, wherein a plurality of annular layers composed of said segment plates and having a total of 42 coil slots are supported by a stator frame having 12 key bars.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |