Communications Project

Document Type:Master's Thesis
Name:Chad Fair
Title:Synchronous Sampling Sideband Orders from Helical Planetary Gear Sets
Degree:Masters of Science
Department:Mechanical Engineering
Committee Chair: Alfred Wicks
Committee Members:Charles F. Reinholtz
William R. Kelley
Keywords:Synchronous, Sidebands, Vector, averaging, planetary, gear, acquisition, DAQ
Date of defense:August 3, 1998
Availability:Release the entire work immediately worldwide.


The sideband phenomenon is a common but obscure characteristic of the Rotary Dynamics field. In the automotive industry these sidebands have been found to produce a poor sound quality, resulting in customer dissatisfaction and warranty returns. In the interest of continued product improvement, research and development must resolve uncertainties in the current design methods. Qualitative relationships between the sideband characteristics and design parameters have developed in recent years, but the quantitative goal hasn't been achieved. A Synchronous Sampling (SS) data acquisition system is applied to a helical planetary gear set to improve the understanding of the sideband characteristics and enhance the design process. An optical encoder, a component of the SS system, mechanically locked to the rotating system controls the A/D converter to sample at constant shaft angle increments. The phase-locked nature of SS allows the use of vector averaging to significantly lower the noise floor and improve the representation of the order domain. In this work, the advantages of using a SS system with vector averaging capabilities are compared to the disadvantages of using a fixed sampling (FS) system. Utilizing the SS tool, this work also illustrates the influences of loading styles and values and speed on a gearmesh and its dominant sideband orders. Inspection of these influences suggests an opportunity for future work.

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