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Monitoring Railroad Car Bearing/Wheel Defects using Phase Sensitive or Propagation Time Acoustic Detection

IP.com Disclosure Number: IPCOM000112172D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Dreyfus, RW: AUTHOR [+2]

Abstract

An acoustic measuring scheme for recording and transmitting to appropriate communicators impending freight car wheel bearing and wheel total failure is described. Every bearing in each freight car can be uniquely monitored via specially mounted phased acoustic sensors. Some specific defects lead to bearing deterioration and failure in a much shorter time than others.

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Monitoring Railroad Car Bearing/Wheel Defects using Phase Sensitive
or Propagation Time Acoustic Detection

      An acoustic measuring scheme for recording and transmitting to
appropriate communicators impending freight car wheel bearing and
wheel total failure is described.  Every bearing in each freight car
can be uniquely monitored via specially mounted phased acoustic
sensors.  Some specific defects lead to bearing deterioration and
failure in a much shorter time than others.

      A hitherto unused portion of the acoustic signals is the
(relative) temporal input to the acoustic sensors in interpreting the
detected acoustic amplitudes.  One or more pairs of acoustic
transducers are mounted over and under each axle of the freight car
along an axle diameter as shown in the Figure to form a
phase-detector array.  Each pair is connected to a computer channel
which analyzes the frequency spectrum, including both phase
relationships and intensity of the acoustic emissions generated by
both the bearing/axle and wheel/rail contact.  Defects are detected
by analyzing the acoustic signals that arrive at the two transducers
within a small time slot or window of one another.  The signal
arrival time is determined by the speed of sound and the distance
traversed in the steel, which at most comprises a path that includes
the axle, bearing and some distance within the journal box.  Random
acoustically generated sounds, that is those not arriving within a
given time slot or lacking periodicity with axle rotation will not
arrive i...