Magnetic-force-tunable multimodal resonant inertial impact piezoelectric rotary motor

A novel multimodal resonant inertial impact piezoelectric rotary motor with adjustable magnetic force was designed, assembled, and tested. This motor features a compact structure with an adjustable distance between the regulating magnet and the piezoelectric twin bimorph, enabling adaptation to different output speeds, step sizes, and load requirements. Under sinusoidal signal excitation, the upper and lower vibrations of the piezoelectric twin bimorph produce different displacements due to the magnetic force, thereby achieving directed motion of the motor. The motor can operate in first-order and second-order resonant modes, exhibiting different motion characteristics and angular displacement resolution. By establishing a dynamic model of the piezoelectric twin bimorph, the motor's dynamic characteristics were studied, and an experimental platform was set up to test the motor's performance. Experimental results show that in the first-order resonance mode, the motor achieves a maximum speed of 0.87 rad/s, a maximum load capacity of 20 N mm, and a maximum step size of 5.3 mrad at an excitation frequency of 160 Hz and an excitation voltage of 120 VP-P. In the second-order resonance mode, the motor achieves a minimum step size of 6.6 μrad at an excitation frequency of 910 Hz and an excitation voltage of 40 VP-P. The motor is driven by a single harmonic signal and operates in a resonant state, enhancing output characteristics and providing multiple operating modes by adjusting the magnetic force distance. It demonstrates significant application potential in fields such as precision instruments and medical devices.