DAMAGE DETECTION METHOD AND APPARATUS FOR MACHINE ELEMENTS UTILIZING VIBRATIONS THEREFROM

• US 3,677,072 A
• Filed: 10/30/1970
• Issued: 07/18/1972
• Est. Priority Date: 10/30/1970
• Status: Expired due to Term

• Current Assignee: Bernard Darrel, Bjorn Weichbrodt
• Original Assignee: Bernard Darrel, Bjorn Weichbrodt
• Inventors: Weichbrodt, Bjorn, Darrel, Bernard
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Korkosz, Arthur E.
• Application Number:
  US05/085,332
• Time in Patent Office: 627 Days
• Field of Search: 73/67,71.4,69 340/261
• US Class Current: 73/593
• CPC Class Codes: F16C 19/06 with a single row or balls
• CPC Class Codes: F16C 19/527 related to vibration and noise
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 13/021 Gearings
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01N 2291/2696 Wheels, Gears, Bearings

Abstract

A system for detection of damage to a machine element in rolling engagement with another machine element utilizing vibrations produced by such damage. The peak value of the vibration signal obtained from the machine elements is compared with the mean value of the rectified vibration signal to obtain a ratio which is an indication of and the extent of the damage to the machine element.

Claims

1. A system for detecting damage to a rolling element in a pair of engaging rolling elements, said damage producing a component of vibration having a periodicity corresponding to the periodicity of rotation of said rolling element and having a peak above the level of other vibrations of said rolling elements, a vibration sensor coupled to said rolling element for sensing the vibrations thereof and converting said vibrations into a first electrical signal, means for deriving a second signal from said first signal corresponding to the peak value of said first electrical signal, means for deriving a third signal from said first signal corresponding to a mean value of the amplitude of said electrical signal, means for deriving a signal corresponding to the ratio of the amplitudes of said second signal and said third signal, and indicator means responsive to a predetermined level of said third signal corresponding to said peak of said component of vibration, whereby said damage is detected.

2. The combination of claim 1 in which signal enhancement means are provided to enhAnce the amplitude of the component of vibration in relation to the amplitude of the other vibrations.

3. The combination of claim 1 in which said rolling element is a rolling element of a bearing.

4. The combination of claim 1 in which said pair of rolling elements are gears in which the teeth of one of said gears engage the teeth of the other of said gears.

5. The combination of claim 1 in which said means for deriving a third signal derives a mean value signal corresponding to the average value of the rectification of said first electrical signal.

6. The combination of claim 1 in which said means for deriving a third signal derives a mean value signal corresponding to the root mean square value of said first electrical signal.

7. The combination of claim 1 in which a network is interfaced in the signal path from said means deriving said third signal to said indicator means, the time constant of said network being large in relation to the period of rotation of said rolling element.