| 摘要 |
In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration, resulting from an expansion and a contraction of a vibrator in a direction of a central axis, and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting of the vibrator about the central axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration, resulting from the expansion and the contraction of the vibrator in the direction of the central axis, and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration, resulting from twisting of the vibrator about rotation axis, substantially match. The vibrator includes, stacked in a short side direction of the cross-section, at least one torsional piezoelectric body that generates the torsional secondary resonance vibration or the torsional tertiary resonance vibration, and a piezoelectric body for longitudinal vibration that generates at least the longitudinal primary resonance vibration. |
