US5090944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic-drive device for rotary machinery
Assignee: NGK Insulators Ltd
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Filing: 1987-11-25
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Granted: 1992-02-25
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Expires: 2007-11-25
Abstract
Abstract A magnetic-drive device used for rotary machines, having a high torque transmitting efficiency, causing little temperature elevation of treated fluids and exhibiting mechanical strength and thermal shock resistance. The device comprises a chamber formed by combining a front casing with a rear casing to accommodate a rotor supporting a driven magnet. The rear casing consists of a cylindrical partition walled up at its one end with a bottom portion and provided with a flange portion on the other end, which partition having a thickness of 1.5-8 mm and consisting of a ceramic material having a specific resistance of at least 10 7 Ω-cm. A driving magnet arranged outside the partition is magnetically coupled with the driven magnet through the partition.
Inventors
- 👤 Osamu Kyo
- 👤 Yasuo Akitsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:07
CPC Classifications
B; B01; B01F; B01F33/00; B01F33/45; B01F33/453; B01F33/4531; B01F33/4534
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
149 words
A magnetic-drive device for rotary machinery comprising: a driving motor and a rotatable motor driven by a magnetic coupling means including a driving magnet fixed on a magnetic holder connected with said driving motor and a driven impeller magnet fixed on a rotor of said rotatable motor, said driving magnet and the driven impeller magnet being combined with each other; and a chamber accomodating said rotatable motor and having a cylindrical partition defining the periphery of the chamber, said partition having a thickness of 1.5-8 mm and comprising a ceramic material having zirconia as a main ingredient, containing 1-5%, based on the weight of the main ingredient, of alumina (Al 2 O 3 ), silica (SiO 2 ) and an alkaline metal oxide, and having a specific resistance of at least 10 7 Ω -cm, through which partition the driving magnet and the driven impeller magnet are magnetically coupled.
Claim 2
Dependent Claim
149 words
A magnetic-drive device for rotary machinery comprising: a driving motor and a rotatable motor driven by a magnetic coupling means including a driving magnet fixed on a magnetic holder connected with said driving motor and a driven impeller magnet fixed on a rotor of said rotatable motor, said driving magnet and the driven impeller magnet being combined with each other; and a chamber accomodating said rotatable motor and having a cylindrical partition defining the periphery of the chamber, said partition having a thickness of 1.5-8 mm and comprising a ceramic material having zirconia as a main ingredient, containing 1-5%, based on the weight of the main ingredient, of alumina (Al 2 O 3 ), silica (SiO 2 ) and an alkaline metal oxide, and having a specific resistance of at least 10 7 Ω -cm, through which partition the driving magnet and the driven impeller magnet are magnetically coupled.
Claim 3
Dependent Claim
26 words
A device as claimed in claim 1 wherein the main ingredient is a zirconia partially stabilized with 2.0-4.0 mole % of Y 2 O 3 .
Claim 4
Dependent Claim
26 words
A device as claimed in claim 2 wherein the main ingredient is a zirconia partially stabilized with 2.3-3.5 mole % of Y 2 O 3 .
References Cited (Backward Citations)
US3411450A
Cited
GB1242243A
Cited
US3877844A
Cited
GB1496035A
Cited
US4120618A
Cited
US4065234A
Cited
US4115040A
Cited
US4197474A
Cited
US4184090A
Cited
US4207485A
Cited
US4277707A
Cited
US4336339A
Cited
JPS59180099A
Cited
US4585499A
Cited
DE3337086A1
Cited
US4525464A
Cited
US4722661A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-24 | 1995-08-26 | 1996-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-24 | 1999-08-26 | 2000-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-24 | 2003-08-26 | 2004-02-25 | $7700.00 | Window Closed / Lapsed |