Frequency capture characteristic of a vibration system driven by four counterrotating unbalanced rotors.

This study investigates the frequency capture characteristic of four unbalanced rotors in multi-frequency ranges. First, using the average method, the synchronous condition of four unbalanced rotors in a vibration system is derived. Then, the stability condition of the vibration system is deduced, which meets the Routh-Hurwitz criterion. On the basis of the theoretical analysis, the phase difference in steady states and the resultant force on the rigid body at different excitation frequency regions are discussed numerically. Five sets of experiments are done to investigate synchronization and the Sommerfeld effect. The results prove that the vibration system has three motion states according to the excitation frequency in different frequency regions. Two stable states appear in the near-resonance region of the system. This study concludes that the synchronization of unbalanced rotors formed before and after the natural frequency is crucial for the occurrence of the Sommerfeld effect. This work can provide theoretical and experimental reference for the design of new vibration equipment in engineering. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Science & Technology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)