THE ANALYSIS OF GEAR NOISE EXCITATION

This paper discusses the main forms of gear analysis which can be used to study transmission noise and ways in which they can be related to gear errors. Frequency analysis is a powerful tool in the study of gear noise problems. In order to understand fully the resulting spectra it is necessary to understand the nature of gear noise and its sideband structure. In many cases a simple Fourier analyser can give good results if used with care and with attention to speed variations. Signature analysis is a more complicated form of frequency analysis available on some sophisticated analysis systems. It gives a concise representation of the noise over any speed range of interest. It relies on speed variations during test runs. Because the speed is increasing (or decreasing) during runs, the data sample times are restricted. This is to ensure that speed changes by only a small amount during capture of each data block. The consequence of this is that frequency resolution is limited and precise identification of sidebands is sometimes impossible. Cepstrum analysis is a method of resolving particular gear meshes but may not always be related directly to subjective assessment of the noise problem. Probably the most useful form of analysis is the order locked spectrum. This can be performed using several of the relatively inexpensive portable analysers currently available with the provision of a suitable external sampling signal. This may cause difficulties depending on the frequency range and/or the resolution required. The sampling rate must be at least 2.5 times the maximum frequency of interest which, when higher harmonics are required, can be over 200 samples per revolution. (TRRL)

• Corporate Authors:

  Modino Press Limited

  Keswick House, 3 Greenway
  London N20 8EE,   England 
• Authors:
  • Dale, A K
• Publication Date: 1984-6

Media Info

• Features: Figures;
• Pagination: p. 12-14
• Serial:
  • Society of Environmental Engineers, Journal of
  • Volume: 101
  • Issue Number: 23-2
  • Publisher: Society of Environmental Engineers

Subject/Index Terms

• TRT Terms: Analysis; Defects; Evaluation and assessment; Fourier analysis; Frequency (Electromagnetism); Frequency analyzers; Gears; Mathematical analysis; Noise; Sound; Speed; Transmissions
• ITRD Terms: 6471: Analysis (math); 5238: Defect (tech); 9020: Evaluation (assessment); 6997: Frequency; 6748: Sound; 5408: Speed; 1333: Transmission (veh)
• Subject Areas: Environment; Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00390283
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Dec 30 1984 12:00AM