Acoustic Analysis of Cylindrical, Conical and Worm Gears

Abstract:

The paper aims to determine the characteristic frequencies of an electric drill, by measuring and analyzing comparatively the variations of the acoustic intensity level, using the Fast Fourier Transform method (FFT). This was applied using a stand which had been specifically developed for the presented work. In two channel and multichannel systems, digital methods have been used for the calculation of cross properties as they were the only practical methods. Using digital techniques has gained considerable ground, being nowadays applied to problems once solved by resorting to analog methods. The increasing use of Fast Fourier Transform methods is found in single channel real time narrow band measurements and the Digital Filtering is replacing the Analog Filter bank which was used as the basis for real time analyzers operating with constant percentage bandwidth.

• Periodical: Materials Science Forum (Volume 957)
• Pages: 211-220
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.957.211
• Online since: June 2019
• Authors: Cornel-Cristian Enciu*, Cristian Tarba, Cristian Barbulescu
• Keywords: Acoustic Analysis, Fast Fourier Transform, Sound Intensity

References

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[6] C. Bărbulescu, STRMICM-CIUPCM, The noise level evaluation of gear boxes.

[7] *** www.techmind.org 5. Notations The following symbols were used: - n – the angular speed of the gear - z1 – number of pinion teeth - zM – the number of teeth of the crown of the rotating table of the toothed machine - z2 – number of driven gear teeth - ρrms2 - sound pressure level [ Pa ] - U – the load on the gear - ρ – density of air [ kg m-3 ] - Mt – the torque [ Nm ] - l – intensity [ W m-2 ] - µb – acoustic pressure [ Pa ] - Li= I/I0 (dimensionless) – level of sound intensity - E – natural frequency - c – speed of sound [ m s-1 ] - fM – frequency of teeth.

DOI: 10.1016/0020-7357(74)90016-x