Patent US4250424A successfully refreshed from Google Patents.
US4250424A
Expired / Lapsed
US
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Rotor of synchronous machines
Assignee: Hitachi Ltd
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Filing: 1978-09-26
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Granted: 1981-02-10
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Expires: 1998-09-26
Abstract
Abstract The rotor core of a synchronous motor or a synchronous generator with a permanent magnet is comprised of a multiplicity of laminated thin iron sheets each having as many segments as the poles. Slits are formed between each adjacent segment, and the magnetic reluctance of the slits is made larger than that between the rotor core and the stator core, thereby minimizing the leakage fluxes within the rotor core. Each segment is required to be prevented from being broken away by centrifugal force generated while the machine is in operation. According to the invention, adjacent segments are connected by a non-magnetic material through the slits. The non-magnetic material is fitted in the recesses formed at both sides of the slit in such a manner as to connect them with each other, each of the recesses being positioned substantially parallel to the circumference of the rotor and having a wider bottom than the opening thereof.
Inventors
- 👤 Hiroshi Sento
- 👤 Shoji Tanabe
- 👤 Tadao Shimozu
- 👤 Seiji Yamashita
- 👤 Kunio Miyashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:05
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2753; H02K1/276; H02K21/00; H02K21/46
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
179 words
A rotor of synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having segments divided by a plurality of slits, said segments corresponding in number to the number of poles, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide each pole constituted by said segments of said blanked iron sheets with a specific polarity; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; and a plurality of key members with the ends thereof securely fitted with said recesses across said slits respectively.
Claim 2
Dependent Claim
179 words
A rotor of synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having segments divided by a plurality of slits, said segments corresponding in number to the number of poles, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide each pole constituted by said segments of said blanked iron sheets with a specific polarity; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; and a plurality of key members with the ends thereof securely fitted with said recesses across said slits respectively.
Claim 3
Dependent Claim
20 words
A rotor of synchronous machines according to claim 1, in which said key members are made of a nonmagnetic material.
Claim 4
Dependent Claim
42 words
A rotor of synchronous machines according to claim 1, in which said laminations of said blanked iron sheets each with adjacent segments connected by a plurality of bridges magnetically saturated with a small amount of magnetic flux make up said rotor core.
Claim 5
Dependent Claim
43 words
A rotor of synchronous machines according to claim 1, in which each of said key members includes part of non-magnetic material crossing each of said slits and parts of magnetic material integrated with said part of non-magnetic material and inserted into said recesses.
Claim 6
Dependent Claim
212 words
A rotor of synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having segments divided by a plurality of slits, said segments corresponding in number to the number of poles, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide each pole constituted by said segments of said blanked iron sheets with a specific polarity; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; a plurality of flattened sleeves each with the ends thereof inserted into each of said recesses across each of said slits; and a plurality of pins each inserted in the part of each of said sleeves positioned within each of said recesses so as to anchor said sleeves fast to said recesses.
Claim 7
Dependent Claim
212 words
A rotor of synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having segments divided by a plurality of slits, said segments corresponding in number to the number of poles, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide each pole constituted by said segments of said blanked iron sheets with a specific polarity; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; a plurality of flattened sleeves each with the ends thereof inserted into each of said recesses across each of said slits; and a plurality of pins each inserted in the part of each of said sleeves positioned within each of said recesses so as to anchor said sleeves fast to said recesses.
Claim 8
Dependent Claim
195 words
A rotor of bipolar synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having two segments divided by two slits, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide one pole constituted by one of said segments of each of said blanked iron sheets with the polarity N and the other pole constituted by the other of said segments of each of said blanked iron sheets with the polarity S; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; and a plurality of key members with the ends thereof securely fitted into said recesses across said slits respectively.
Claim 9
Dependent Claim
195 words
A rotor of bipolar synchronous machines comprising: a rotor core including a multiplicity of laminations of blanked iron sheets each having two segments divided by two slits, each of said blanked iron sheets having a center hole, and said laminations being made in such a manner that said holes and said slits of all of said blanked iron sheets are arranged in alignment at the same positions; a plurality of permanent magnets which are received by said center holes of said blanked iron sheets so as to provide one pole constituted by one of said segments of each of said blanked iron sheets with the polarity N and the other pole constituted by the other of said segments of each of said blanked iron sheets with the polarity S; a rotary shaft arranged in said center holes concentrically with said rotor core and adapted to rotate integrally with said rotor core and said permanent magnets; a plurality of recesses formed in both sides of each of said slits and having a bottom wider than the opening; and a plurality of key members with the ends thereof securely fitted into said recesses across said slits respectively.
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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) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |