US3594599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current dynamoelectric machines
Assignee: ZF International UK Ltd
•
Filing: 1969-08-04
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Granted: 1971-07-20
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Expires: 1989-08-04
Abstract
Abstract A direct current dynamoelectric machine has poles in the usual way, but each pole has a first portion formed from steel and a second portion formed from ferrite material. The steel has a lower reluctance than the ferrite material, but in use the flux density is increased by armature reaction in the vicinity of the steel portion, and reduced by armature reaction in the vicinity of the ferrite portion, so that the required characteristics of the machine are obtained with a saving in material. The same effect, utilizing the armature reaction to increase flux density beneath a pole part which has a lower reluctance than the other part of the pole, can be achieved in other ways.
Inventors
- 👤 John Godfrey Wilson West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:43
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/02; H02K23/04; H02K1/00; H02K1/06; H02K1/12; H02K1/17
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
82 words
A direct current dynamoelectric machine having a plurality of poles, and a rotor rotating beneath said poles and producing a conventional armature reaction, each pole having a first pole part beneath which the flux density is increased by armature reaction and a second pole part beneath which the flux density is reduced by armature reaction, said pole parts being circumferentially disposed, and wherein each of said first pole parts is constructed with a lower reluctance than each of said second pole parts.
Claim 2
Dependent Claim
82 words
A direct current dynamoelectric machine having a plurality of poles, and a rotor rotating beneath said poles and producing a conventional armature reaction, each pole having a first pole part beneath which the flux density is increased by armature reaction and a second pole part beneath which the flux density is reduced by armature reaction, said pole parts being circumferentially disposed, and wherein each of said first pole parts is constructed with a lower reluctance than each of said second pole parts.
Claim 3
Dependent Claim
31 words
A machine as claimed in claim 1 in which each pole has two parts formed respectively from steel and ferrite, the steel part constituting the first pole part of each pole.
Claim 4
Dependent Claim
47 words
A machine as claimed in claim 1 in which the first pole part of each pole is formed by a ferrite magnet and associated steel pole piece, and the second pole part of each pole is formed by a thicker ferrite magnet and associated steel pole piece.
Claim 5
Dependent Claim
41 words
A machine as claimed in claim 1 in which each pole is formed entirely from ferrite material, the thickness of the ferrite material varying from a maximum to a minimum to provide the first and second pole parts of each pole.
Claim 6
Dependent Claim
17 words
A machine as claimed in claim 2 in which the steel part is constituted by the stator.
References Cited (Backward Citations)
US2048161A
Cited
US2059886A
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US2193406A
Cited
US2513227A
Cited
US2993134A
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US3054916A
Cited
US3296471A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |