Round annular multiple freedom degrees ultrasound electric machine and electric excitation method thereof

Abstract

The invention relates to a ring-type multi-degree-of-freedom ultrasonic motor and an electric excitation method, pertaining to the field of ultrasonic motors. The ultrasonic motor comprises a rotor and a stator. The invention is characterized in that the rotor is a spherical rotor (1); the stator is a metal ring (2), and six piezo-electric ceramic pieces (3) are affixed on the flank of the ring stator; three upper bosses (4) are evenly distributed on the periphery of the upper end-face of the ring stator and arranged at the same position of the platform (6) affixed with ceramic pieces to support and drive the spherical stator; the rotor provides the prepress force required by the stator and the rotor; three small bosses (4) corresponding to the positions of the upper bosses (4) are also arranged on the lower end-face of the ring stator to support the whole motor. When the driving signal provides power supply to any two piezo-electric ceramic pieces (3) opposite to each other, the two flexural vibration modes in the face of the stator can be excited out to produce standing waves and drive the spherical rotor to round the spherical center of the rotor and rotate around the axial line parallel with the two piezo-electric ceramic pieces. The ultrasonic motor can realize the rotation of a plurality of rotating shafts; the invention has the advantages of a simple structure, a small size, high efficiency, reliable operation, etc.

Description

Technical field: [0001] The invention relates to an annular multi-degree-of-freedom ultrasonic motor and an electric excitation method, belonging to the field of ultrasonic motors. Background technique: [0002] Ultrasonic motor is a new concept power device that utilizes the inverse piezoelectric effect of piezoelectric material and ultrasonic vibration of elastic body. At present, the multi-degree-of-freedom ultrasonic motor is mostly a rod-type stator and a spherical rotor structure. The rod-type stator uses two bending vibrations and one longitudinal vibration to realize the rotation of the three rotation axes of the rotor. In practice, the frequency of bending vibration is difficult to match with the frequency of longitudinal vibration, but the driving frequency of the motor can only be one, so the driving efficiency of the motor will be low, and the output performance of the motor will be affected. In addition, because the rod-type multi-degree-of-freedom motor utiliz...

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Problems solved by technology

In practice, the frequency of bending vibration is difficult to match with the frequency of longitudinal vibration, but the driving frequency of the motor can only be one, so the driving efficiency of the motor will be low, and the output performance of the motor will be affected

In addition, because the rod-type multi-degree-of-freedom motor utilizes the two-bend vibration mode and longitudinal vibration mode, as well as the limitation of the stator assembly size, its axial size is difficult to reduce, which is not conducive to miniaturization, so the application range is limited

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