US4924180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting bearing shaft wear utilizing rotatable magnet means
Assignee: PMC LIQUIFLO EQUIPMENT COMPANY 140 MOUNT BETHEL ROAD WARREN NEW JERSEY A CORP OF NEW JERSEY
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Filing: 1987-12-18
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Granted: 1990-05-08
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Expires: 2007-12-18
Abstract
Abstract A device is provided for measuring bearing or shaft wear in an apparatus utilizing a rotating shaft positioned in a bearing. A plurality of magnets are mounted on the rotating shaft and at least three coils forming at least two pairs of coils are mounted on a stationary housing surrounding the shaft. Means are provided for measuring the change in induced voltage for each pair of coils independent of shaft rotation speed, ambient temperature, the flux density of the magnets and the concentricity of the bearing and shaft diameters.
Inventors
- 👤 Ali M. Nasr
- 👤 Gregory W. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:22
CPC Classifications
F; F16; F16C; F16C17/00; F16C17/12; F16C17/24; G; G01; G01B; G01B7/00; G01B7/14; G01B7/144; G01M; G01M13/00; G01M13/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
179 words
In an apparatus comprising a rotating shaft mounted in a bearing and a stationary housing surrounding said rotating shaft, the improvement comprising a means for detecting wear in said bearing or said shaft including a plurality of magnets mounted about the circumference of said shaft and at least two pairs of coils mounted on said stationary housing surrounding said shaft, the coils being positioned substantially equidistant from each other, each coil being positioned to detect magnetic flux density of said magnets when said shaft rotates, and means for detecting a change in axial position of said rotating shaft independently of speed of shaft rotation by detecting a change in voltage induced in each pair of coils, said means for detecting a change of shaft position independent of shaft rotation speed comprising means for generating a D.C. voltage from each of said coils, means for generating a reference D.C. signal voltage as a function of speed of shaft rotation and means for subtracting said reference D.C. signal voltage from the D.C. voltage generated from each of said pairs of coils.
Claim 2
Dependent Claim
179 words
In an apparatus comprising a rotating shaft mounted in a bearing and a stationary housing surrounding said rotating shaft, the improvement comprising a means for detecting wear in said bearing or said shaft including a plurality of magnets mounted about the circumference of said shaft and at least two pairs of coils mounted on said stationary housing surrounding said shaft, the coils being positioned substantially equidistant from each other, each coil being positioned to detect magnetic flux density of said magnets when said shaft rotates, and means for detecting a change in axial position of said rotating shaft independently of speed of shaft rotation by detecting a change in voltage induced in each pair of coils, said means for detecting a change of shaft position independent of shaft rotation speed comprising means for generating a D.C. voltage from each of said coils, means for generating a reference D.C. signal voltage as a function of speed of shaft rotation and means for subtracting said reference D.C. signal voltage from the D.C. voltage generated from each of said pairs of coils.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1 having two pairs of coils comprising four coils.
Claim 4
Dependent Claim
13 words
The apparatus of claim 1 having two pairs of coils comprising three coils.
Claim 5
Dependent Claim
186 words
In a sealed pump comprising a rotatable shaft mounted in a bearing, a stationary sealed housing surrounding said rotating shaft, a plurality of inner magnets mounted on said rotatable shaft, a motor driven shell surrounding said housing and a plurality of outer magnets mounted on said shell, the improvement comprising means for detecting wear in said bearing or said shaft including at least two pairs of coils mounted on said stationary housing surrounding said shaft, the coils being positioned to detect magnetic flux density of said inner magnets when said shaft independently of speed of shaft rotation rotates and means for detecting a change in axial position of said rotating shaft by detecting a change in voltage induced in each pair of coils, said means for detecting a change of shaft position independent of shaft rotation speed comprising means for generating a D.C. voltage from each of said coils, means for generating a reference D.C. signal voltage as a function of speed of shaft rotation and means for subtracting said reference D.C. signal voltage from the D.C. voltage generated from each of said pairs of coils.
Claim 6
Dependent Claim
186 words
In a sealed pump comprising a rotatable shaft mounted in a bearing, a stationary sealed housing surrounding said rotating shaft, a plurality of inner magnets mounted on said rotatable shaft, a motor driven shell surrounding said housing and a plurality of outer magnets mounted on said shell, the improvement comprising means for detecting wear in said bearing or said shaft including at least two pairs of coils mounted on said stationary housing surrounding said shaft, the coils being positioned to detect magnetic flux density of said inner magnets when said shaft independently of speed of shaft rotation rotates and means for detecting a change in axial position of said rotating shaft by detecting a change in voltage induced in each pair of coils, said means for detecting a change of shaft position independent of shaft rotation speed comprising means for generating a D.C. voltage from each of said coils, means for generating a reference D.C. signal voltage as a function of speed of shaft rotation and means for subtracting said reference D.C. signal voltage from the D.C. voltage generated from each of said pairs of coils.
Claim 7
Dependent Claim
13 words
The pump of claim 4 having two pairs of coils comprising four coils.
Claim 8
Dependent Claim
13 words
The pumps of claim 4 having two pairs of coils comprising three coils.
Claim 9
Dependent Claim
24 words
The pump of claim 4, 5 or or 6 including means for substantially isolating the magnetic flux of said outer magnets from said coils.
References Cited (Backward Citations)
US3194990A
Cited
US2805677A
Cited
US3193784A
Cited
US3381216A
Cited
US3981621A
Cited
US4199718A
Cited
US4665361A
Cited
US4732494A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |