Classical traveling-wave ultrasonic motors (TWUMs) usually generate the elliptical clusters on the stator surface through the bending vibration of the annular stator on the basis of piezoelectric excitation, and the torque output and power transmission are realized by friction coupling under the rational preload. Stable and reliable working characteristics attracted the focus of various applications. High energy consumption and low efficiency are restricted factors for the service performance of motors. Displacement amplification and stress regulation based on flexible design become a possible approach to improve motor performances. In this study, a TWUM30 prototype was proposed with consideration of (sub) structure optimization, i.e., tooth height and backlash of the stator elastomer. The flexible design of the rotor structure was carried out for consideration of the contact area and stress regulation. After integrated bonding of the stator and PZT4, the electrical and vibration characteristics of the stator prototype are measured by an impedance analyzer and high-precision laser micro-displacement sensor. Results showed that the proposed TWUM30 is capable of operation under low-voltage driving (41.9 kHz @ 80 V_p), and the extreme mechanical performances presented the stall toque of 64mN∙m and the no-load speed of 153.8 rpm. With the combination of the flexible design and systematic integrated manufacturing of the stator/rotor, low-voltage driving of the TWUM30 motor under ultra-low preload was realized at low cost and the adverse effects of excessive preload were suppressed. This study is expected to provide support for high reliability design and long-life service of the TWUMs. It also provides a realistic possibility for the flexible design and application of energy-saving and high-efficient traveling-wave piezoelectric drivers.

经典的行波超声电机（TWUMs）通常在压电激励的基础上，通过环形定子的弯曲振动在定子表面产生椭圆簇，在合理的预紧力下通过摩擦耦合实现扭矩输出和动力传递。稳定可靠的工作特性吸引了各种应用的关注。高能耗和低效率是制约电机使用性能的因素。基于柔性设计的位移放大和应力调节成为提高电机性能的可能途径。在这项研究中，考虑到（子）结构优化，即定子弹性体的齿高和齿隙，提出了一个 TWUM30 原型。考虑到接触面积和应力调节，对转子结构进行了柔性设计。定子与PZT4一体化键合后，通过阻抗分析仪和高精度激光微位移传感器测量定子样机的电气和振动特性。结果表明，所提出的 TWUM30 能够在低压驱动（41.9 kHz @ 80 V_p )，极端的机械性能表现出 64mN∙m 的失速扭矩和 153.8 rpm 的空载速度。通过定转子的灵活设计与系统集成制造相结合，以低成本实现了TWUM30电机在超低预紧下的低压驱动，抑制了过大预紧带来的不利影响。该研究有望为TWUM的高可靠性设计和长寿命服务提供支持。这也为节能高效的行波压电驱动器的灵活设计和应用提供了现实可能。