Condition based monitoring by vibrational analysis

• US 6,526,831 B2
• Filed: 11/08/2001
• Issued: 03/04/2003
• Est. Priority Date: 09/28/1999
• Status: Expired due to Fees

• Current Assignee: Teledyne Scientific & Imaging, LLC (Teledyne Technologies Incorporated)
• Original Assignee: Innovative Technology Licensing LLC
• Inventors: Ben-Romdhane, Mohamed
• Primary Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US10/035,511
• Publication Number:
  US 20020083773A1
• Time in Patent Office: 481 Days
• Field of Search: 736/60, 736/59, 735/79, 702/77, 702/33, 702/34, 702/35, 702/36
• US Class Current: 73/660
• CPC Class Codes: F16C 19/52 with devices affected by abnormal or undesired conditions
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis

Abstract

An apparatus and method monitors the condition of a bearing/shaft assembly by forming diagnostics based on spectral analysis of assembly'"'"'s vibration. Baseline parameters are determined by a microprocessor analysis of the vibration spectra, comparing actual peaks to the peaks predicted by a model. The microprocessor estimates rotation rate and preferably number of rolling elements by attempting to fit the model to the actual vibrational spectrum, by varying the assumptions. Baseline profiles are formed from one or more selected tones and preferably also harmonics thereof, to characterize the bearing/shaft assembly. The baseline profiles and parameters are compared against later acquired vibrational characteristics, and the comparison is used to diagnose bearing and/or shaft conditions.

Claims

1. A method of processing a sampled, digitized signal to obtain improved frequency resolution in a spectral sub-band, suitable for analyzing the vibrational spectrum of a machine, comprising the steps of:

computing an output value Y_n corresponding to each discrete time t_n, according to the formula;