Investigation of non-contact bearing systems based on ultrasonic levitation
Autor: Su Zhao
ISBN: 978-3-941416-70-3
Dissertation, Leibniz Universität Hannover, 2010
Herausgeber der Reihe: Jörg Wallaschek
Band-Nr.: IDS 04/2010
Umfang: 113 Seiten, 0 Abbildungen
Schlagworte: non-contact bearing systems, ultrasonic levitation, akustische Ultraschall-Levitation, Ultraschall-Levitation
Kurzfassung: Non-contact bearings based on acoustic/ultrasonic levitation are investigated in this thesis. Both standing wave type and squeeze film type ultrasonic levitation are investigated theoretically and experimentally. A new configuration of standing wave levitation is presented which is able to levitate large planar object at a position of multiple times of a half wavelength of the sound wave. The theoretical model for the proposed levitation system is established and a prototype system is constructed accordingly. A CD is successfully levitated with the proposed system at a height of half a wavelength. Squeeze film type ultrasonic levitation is investigated theoretically to find the crucial design parameters and to improve the levitation capacity. Two analytical models based on acoustic theory and fluid dynamics are presented and compared. The governing fluid dynamics equation is solved numerically to obtain precise pressure distributions. Based on the theoretical investigation, a novel non-contact journal bearing is developed for suspension of a solid steel spindle with diameter of 50 mm.
