Patent US3874750A successfully refreshed from Google Patents.
US3874750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thrust bearings
Assignee: Northrop Grumman Properties Ltd
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Filing: 1973-03-26
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Granted: 1975-04-01
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Expires: 1993-03-26
Abstract
Abstract A permanent magnet thrust bearing in which there is provided a pair of members mounted respectively on a shaft and a fixed body, with one of said members being formed from high permeability material and the other member being a permanent magnet, with said members being continuously presented to each other so in use the shaft rotates relative to the fixed body so that the magnetic flux of said permanent magnet serves to locate said shaft axially with respect to the body.
Inventors
- 👤 Bernard James Greig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:21
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/0408; F16C32/041; F16C32/0417
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A permanent magnet thrust bearing including a stationary member, a shaft, and a member mounted on the shaft, one of said members being of high permeability material and the other said members comprising a permanent magnet, the members being continously presented to each other so that in use during rotation of the shaft, the magnetic flux serves to locate the shaft axially with respect to the stationary member, said one member being mounted on said shaft, said other member being annular and having opposite axial faces and a pair of annular pole pieces located against said opposite axial faces of the other member.
Claim 2
Dependent Claim
103 words
A permanent magnet thrust bearing including a stationary member, a shaft, and a member mounted on the shaft, one of said members being of high permeability material and the other said members comprising a permanent magnet, the members being continously presented to each other so that in use during rotation of the shaft, the magnetic flux serves to locate the shaft axially with respect to the stationary member, said one member being mounted on said shaft, said other member being annular and having opposite axial faces and a pair of annular pole pieces located against said opposite axial faces of the other member.
Claim 3
Dependent Claim
37 words
The thrust bearing as claimed in claim 1 wherein each of said pole pieces has a frusto-conical inner peripheral surface and the smaller diameter axial end of each pole piece being arranged adjacent to said other member.
Claim 4
Dependent Claim
16 words
The thrust bearing as claimed in claim 2 wherein said pole pieces are of soft iron.
Claim 5
Dependent Claim
19 words
The thrust bearing as claimed in claim 2 wherein an adhesive secures said pole pieces to said other member.
Claim 6
Dependent Claim
16 words
The thrust bearing as claimed in claim 2 wherein said pole pieces are of mild stee.
Claim 7
Dependent Claim
92 words
A permanent magnet thrust bearing including a stationary member, a shaft of high permeability material, and a member on the shaft, one of said members being constituted by a portion of the shaft and the other of said members comprising a permanent magnet, the members being continuously presented to each other so that in use during rotation of the shaft, the magnetic flux serves to locate the shaft axially with respect to the stationary member, said shaft being hollow anD said permanent magnet being received in one axial end of the shaft.
Claim 8
Dependent Claim
92 words
A permanent magnet thrust bearing including a stationary member, a shaft of high permeability material, and a member on the shaft, one of said members being constituted by a portion of the shaft and the other of said members comprising a permanent magnet, the members being continuously presented to each other so that in use during rotation of the shaft, the magnetic flux serves to locate the shaft axially with respect to the stationary member, said shaft being hollow anD said permanent magnet being received in one axial end of the shaft.
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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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |