行波超声马达传动机理的研究（一）——运动传递机理及定子中存在弯曲行波的条件

Research on Transmission Mechanism of Piezoelectric Traveling Wave Ultrasonic Motors Part I: Mechanism of Motion Transmission and Conditions for the Existence of a Bending Traveling Wave in the Stator

首先基于几何分析法研究了压电行波超声马达的运动传递机理，重点分析了驻波的产生和行波的合成原理，与转子相接触的定子表面质点的椭圆运动。然后基于弹性动力学方法研究了在定子中存在弯曲行波的条件，得出旋转型压电行波超声马达定子中弯曲行波的产生是基于同频和同节线的两个正交弯曲振型的叠加规律。

The mechanism of the transmission of motion from the stator to the rotot of a piezoelectric traveling wave ultrasonic motor is geometrically studied with emphasis on the principles of the generation of standing waves, the composition of a traveling wave ,and the elliptic motion of the points on the surface of the stator being in contact with the rotor.The condition for the existence of the bending traveling wave in the stator is discussed in term of elastic dynamic mechanics.It is concluded that the bending traveling wave is generated from the superimposition of two orthogonal bending eigen vibratios with the same frequency and the same number of nodal lines.From the conclusion it is required that the stator should be perfectly circular symmetry.