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Record 4 of 4679
Understanding Vibration Spectra of Planetary Gear Systems for Fault Detection
Author and Affiliation:
Mosher, Marianne(NASA Ames Research Center, Moffett Field, CA, United States)
Abstract: An understanding of the vibration spectra is very useful for any gear fault detection scheme based upon vibration measurements. The vibration measured from planetary gears is complicated. Sternfeld noted the presence of sidebands about the gear mesh harmonics spaced at the planet passage frequency in spectra measured near the ring gear of a CH-47 helicopter. McFadden proposes a simple model of the vibration transmission that predicts high spectral amplitudes at multiples of the planet passage frequency, for planetary gears with evenly spaced planets. This model correctly predicts no strong signal at the meshing frequency when the number of teeth on the ring gear is not an integer multiple of the number of planets. This paper will describe a model for planetary gear vibration spectra developed from the ideas started in reference. This model predicts vibration to occur only at frequencies that are multiples of the planet repetition passage frequency and clustered around gear mesh harmonics. Vibration measurements will be shown from tri-axial accelerometers mounted on three different planetary gear systems and compared with the model. The model correctly predicts the frequencies with large components around the first several gear mesh harmonics in measurements for systems with uniformly and nonuniformly spaced planet gears. Measurements do not confirm some of the more detailed features predicted by the model. Discrepancies of the ideal model to the measurements are believed due to simplifications in the model and will be discussed. Fault detection will be discussed applying the understanding will be discussed.
Publication Date: Jan 01, 2003
Document ID:
20030054510
(Acquired Jun 10, 2003)
Subject Category: STRUCTURAL MECHANICS
Document Type: Preprint
Meeting Information: ASME/AGMA 2003 International Power Transmission and Gearing; 2-6 Sep. 2003; Chicago, IL; United States
Meeting Sponsor: American Society of Mechanical Engineers; United States
American Gear Manufacturers Association; Alexandria, VA, United States
Contract/Grant/Task Num: RTOP 704-01-30
Financial Sponsor: NASA Ames Research Center; Moffett Field, CA, United States
Organization Source: NASA Ames Research Center; Moffett Field, CA, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: HARMONICS; GEAR TEETH; MECHANICAL DRIVES; FAULT DETECTION; VIBRATION MEASUREMENT; MATHEMATICAL MODELS; FREQUENCIES; VIBRATIONAL SPECTRA; CH-47 HELICOPTER; ACCELEROMETERS; VIBRATION METERS; SIDEBANDS
Availability Source: Other Sources
Availability Notes: Abstract Only
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