Patent US4614628A successfully refreshed from Google Patents.
US4379291A
Expired / Lapsed
US
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Bearing failure indicator for rotating electric machines
Assignee: TEXAS EASTERN SCIENTIFIC RES Inc
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Filing: 1979-09-04
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Granted: 1983-04-05
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Expires: 1999-09-04
Abstract
Abstract In a squirrel cage type of induction motor, conductive strips insulated from the stator are circularly spaced, ninety degrees apart, and project 0.003 inches into the rotor-to-stator clearance space. Upon excessive lateral rotor movement, it contacts a strip, closing a low voltage circuit triggering an alarm and de-energizing the motor. A reset button must be pressed to enable starting the motor.
Inventors
- 👤 Larry E. Hubbard
- 👤 Clifford A. Rhorer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:03
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/02; H02K17/30; G; G01; G01R; G01R31/00; G01R31/34; H02K11/00; H02K11/20; H02K11/30; H02K11/35; H02K11/40
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
216 words
In an electrical machine having a stator which is generally symetrical about an axis, and a rotor coaxial with the stator, with a plurality of pole portions on the stator, the improvement comprising: sensor means having a fixed position relative to said stator and including a contact portion operable as a circuit switch contactor in response to radial movement of said rotor relative to said stator; a source of electrical energy; electronic switch means having a control element in series circuit relationship with said contact portion and said rotor and said source in a sensor circuit, said contact portion and said rotor serving as a normally-open sensor switch whereby said sensor circuit is non-conducting when said rotor is not contacting said contact portion, but conducting when said rotor contacts said contact portion; a relay including an operator coil in series circuit with said source and a load circuit path of said electronic switch means, and said relay including relay contactor means operable by said coil responsive to conduction of current through said load circuit path and coil to operate said contactor means; and an indicator circuit including an indicator and a normally-open contact portion of said relay contactor means, for energizing said indicator in response to said operation of said contactor means by said relay coil.
Claim 2
Dependent Claim
216 words
In an electrical machine having a stator which is generally symetrical about an axis, and a rotor coaxial with the stator, with a plurality of pole portions on the stator, the improvement comprising: sensor means having a fixed position relative to said stator and including a contact portion operable as a circuit switch contactor in response to radial movement of said rotor relative to said stator; a source of electrical energy; electronic switch means having a control element in series circuit relationship with said contact portion and said rotor and said source in a sensor circuit, said contact portion and said rotor serving as a normally-open sensor switch whereby said sensor circuit is non-conducting when said rotor is not contacting said contact portion, but conducting when said rotor contacts said contact portion; a relay including an operator coil in series circuit with said source and a load circuit path of said electronic switch means, and said relay including relay contactor means operable by said coil responsive to conduction of current through said load circuit path and coil to operate said contactor means; and an indicator circuit including an indicator and a normally-open contact portion of said relay contactor means, for energizing said indicator in response to said operation of said contactor means by said relay coil.
Claim 3
Dependent Claim
15 words
The improvement of claim 1 wherein: said electronic switch means is a silicon controlled rectifier.
Claim 4
Dependent Claim
91 words
The improvement of claim 1 wherein said stator has windings, the improvement further comprising: motor control circuit means coupled to said windings for applying line current to said windings, and including magnetically closed and held line circuit breakers, and a breaker operating coil, and a coil energization holding circuit, said relay contactor means including a normally-closed contact portion in series in said holding circuit, whereby operation of said contactor means by said relay coil opens said holding circuit to disable said breaker operating coil from maintaining said line circuit breakers closed.
Claim 5
Dependent Claim
65 words
The improvement of claim 3 wherein: said motor control circuit means are included in a magnetic motor starter assembly; and said energy source and electronic switch means and relay are in a clearance monitor assembly, with two leads from said assembly to said motor serving as a path from said control element to said contact portion and as a rotor-to-source path in said sensor circuit.
Claim 6
Independent Claim
81 words
A method of sensing impending stator contact by a co-axial rotating rotor of an electric motor comprising the steps of: placing sensor means in the circular space between the rotor and stator; applying a sensor circuit voltage across the space between the rotor and sensor means; using contact of the rotor with the sensor means as a switch closing a sensor circuit to establish a current in the sensor circuit; and using current in the sensor circuit to energize annunciator means.
Claim 7
Independent Claim
81 words
A method of sensing impending stator contact by a co-axial rotating rotor of an electric motor comprising the steps of: placing sensor means in the circular space between the rotor and stator; applying a sensor circuit voltage across the space between the rotor and sensor means; using contact of the rotor with the sensor means as a switch closing a sensor circuit to establish a current in the sensor circuit; and using current in the sensor circuit to energize annunciator means.
Claim 8
Dependent Claim
21 words
The method of claim 5 and further comprising the step of: using current in the sensor circuit to de-energize the motor.
Claim 9
Dependent Claim
51 words
The method of claim 5 or 6 wherein current in the sensor circuit is used by causing it to fire a silicon controlled rectifier, the firing of which operates a power relay to apply energy to an annunciator and break a holding circuit in a magnetic starter assembly for the motor.
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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) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |