US4481819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting metal wipe damages of plane bearing
Assignee: Hitachi Ltd
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Filing: 1983-02-09
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Granted: 1984-11-13
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Expires: 2003-02-09
Abstract
Abstract A method and apparatus for detecting metal wipe damages of plane bearings with the metal wipe generating an ultrasonic signal as an acoustic emission signal when it occurs. The ultrasonic signal has a periodic appearance therefore, the metal wipe damages, can be detected by monitoring the periodic nature of the ultrasonic signal. The ultrasonic signal is received by a transducer fixed to the plane bearing with the periodic nature of the received ultrasonic signal being computed by a processing unit so as to provide a output signal of the occurrence of a metal wipe when the received ultrasonic signal is periodic.
Inventors
- 👤 Takao Yoneyama
- 👤 Ichiya Satoh
- 👤 Sanshiro Obara
- 👤 Tomoaki Inoue
- 👤 Tsuguaki Koga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:59
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
211 words
An apparatus for detecting a metal wipe of plane bearing means, the apparatus comprising means disposed in an area of the plane bearing means for receiving an ultrasonic signal generated by the metal wipe and for producing an output signal thereof, means for receiving the output signal and for converting the same into a pulse signal, means for receiving and storing the pulse signals received over a predetermined period of time, means for computing a ratio of a stored pulse signal with a previously predetermined period of time to a currently stored pulse signal and for providing an output signal indicative of an occurrence of the metal wipe, said means for computing a ratio includes a gate circuit means for receiving a pulse signal from said means for receiving and converting, means for operating the gate circuit means so as to provide for alternate output signals to said means for receiving and storing the pulse signals, divider means for receiving an output signal from said means for receiving and storing the pulse signals and for providing a divided output signal, and means responsive to the output signal of the means for receiving and converting and the divider means for providing the output signal indicative of the occurrence of a metal wipe.
Claim 2
Independent Claim
211 words
An apparatus for detecting a metal wipe of plane bearing means, the apparatus comprising means disposed in an area of the plane bearing means for receiving an ultrasonic signal generated by the metal wipe and for producing an output signal thereof, means for receiving the output signal and for converting the same into a pulse signal, means for receiving and storing the pulse signals received over a predetermined period of time, means for computing a ratio of a stored pulse signal with a previously predetermined period of time to a currently stored pulse signal and for providing an output signal indicative of an occurrence of the metal wipe, said means for computing a ratio includes a gate circuit means for receiving a pulse signal from said means for receiving and converting, means for operating the gate circuit means so as to provide for alternate output signals to said means for receiving and storing the pulse signals, divider means for receiving an output signal from said means for receiving and storing the pulse signals and for providing a divided output signal, and means responsive to the output signal of the means for receiving and converting and the divider means for providing the output signal indicative of the occurrence of a metal wipe.
Claim 3
Dependent Claim
17 words
An apparatus according to claim 1, wherein said gate circuit means includes at least two individual gates.
Claim 4
Dependent Claim
32 words
An apparatus according to claim 2, wherein said means for receiving and storing the pulse signals includes at least two digital memory circuit means respectively receiving output signals from said individual gates.
Claim 5
Dependent Claim
32 words
An apparatus according to claim 3, wherein each of said memory circuit means is adapted to clear a stored signal upon an input of a subsequent output signal from the respective gates.
Claim 6
Dependent Claim
19 words
An apparatus according to claim 3, wherein said means for operating the gate circuit means includes a timer means.
Claim 7
Dependent Claim
22 words
An apparatus according to claim 5, wherein said means responsive to the output signal of the receiving means includes an AND gate.
Claim 8
Dependent Claim
16 words
An apparatus according to claim 6, wherein said means for receiving and converting includes a comparator.
Claim 9
Dependent Claim
40 words
An apparatus according to claim 1, further comprising means interposed between said means for receiving the ultrasonic signal and said means for receiving and converting for determining whether the apparatus is in a preliminary turning operation or a normal operation.
Claim 10
Dependent Claim
35 words
An apparatus according to claim 8, wherein said means for determining includes a rotation decision circuit means for receiving a rotation frequency signal and the output signal from said means for receiving an ultrasonic signal.
Claim 11
Dependent Claim
65 words
An apparatus according to claim 9, further comprising a first amplifier means receiving an output signal from said rotation decision circuit means, a filter means for receiving an output signal from said first amplifier means, a second amplifier means for receiving an output signal from said filter means, and a detector means interposed between said second amplifier means and said means for receiving and converting.
Claim 12
Dependent Claim
21 words
An apparatus according to claim 10, further comprising a counter means for counting the output signal from said means for computing.
Claim 13
Dependent Claim
19 words
An apparatus according to claim 1, further comprising a display means for displaying the count of said counter means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |