Traveling Wave Type Multi-Degree-of-Freedom Spherical Ultrasonic Motor with Built-in Stators

A multi-degree-of-freedom spherical ultrasonic motor with built-in traveling wave stators is proposed, and each traveling wave stator can be controlled independently, the three-degree-of-freedom movement of the spherical rotor is realized by the coordinated control of the three traveling wave stators and the spatial arrangement of the support structures. The motor also has a built-in pre-pressure adjustment structure, which can adjust the pre-pressure of three stators at the same time and make them the same size. The structure and working principle of the motor are expounded in detail. The structure and working principle of the motor are expounded in detail. The finite element method is used to analyze the modal of the traveling wave stator, and the transient trajectory of the driving part is simulated. Finally, the working principle was verified on the prototype, and the mechanical output performance of the prototype was tested: when the excitation voltage of the motor is 400 V and the preload is 100 N, the maximum speed is 45.6 rad/min, the maximum speed output torque is 1.265 Nm; the maximum deflection angle is 43°, and the maximum deflection speed is 56.3 rad/min, the maximum deflection torque is 1.76 Nm, achieves high torque and multiple-degrees-of-freedom. The motor has the advantages of large output force, high integration, and adjustable preload.