A Micro Piezoelectric Motor With Multiple Excitation Modes and Methods

Abstract

To widen the performance of piezoelectric motors, this paper demonstrates a micro piezoelectric motor having multiple driving ways. The stator includes a hollow polygon bar and two groups of PZT plates. PZT plates are symmetrically bonded onto a brass base, and used to actuate the vibration modes of the stator. The symmetrical design enables the motor to operate in two types of vibration modes. The working modes are the second/third-order in-plane bending modes, and can be excited by different ways. Elliptical motion of stator surface points is generated by superposition of two bending modes with the same order. To investigate the feasibility of multi-mode and multi-motivation mechanisms, vibration behaviors of stator driving particles are simulated using ANSYS software. The structural parameters of the stator are strictly designed to harmonize the eigenfrequencies of the vibration modes. The calculated results reveal that the motor performance can be adjusted by selecting different operating modes and excitation ways. The motor performances under various excitation ways and driving modes are also investigated experimentally to validate the proposed design. The dimension of the fabricated prototype motor is 8.3 mm ×7.2 mm×15.0 mm. The maximum torques are respectively 8.3 cN•m and 13.3 cN•m under single-phase and two-phase excitation voltages, when the motor operates in the second-order bending modes. The corresponding no-load speed are respectively 40 rpm and 47 rpm. The maximum torque and speed under the third-order bending modes are much smaller than that under the second-order bending modes.

Improving Output Performance of the Ultrasonic Multicell Piezoelectric Motor by Development the Multi-Rotor Structure

“…The load applied to the motor is determined by the specified load F load and the calculated steady-state motor speed from (7). The average output power is:…”

“…In addition, the modelling, structural and technological problems of piezoelectric structures are related to the constitutive parameters of the piezoelectric materials used in their construction. It should be noted that, despite these problems, progress has been made in the development of modelling methods [7]. Moreover, the development of ultrasonic piezoelectric actuators and motors is made possible by ongoing research into electro-active materials, particularly new ceramic materials and polymers with high 'power density' and low loss [8], [9].…”

Research on interactions between different operating modes of piezoelectric motors

“…PZT plates were symmetrically affixed to two adjacent surfaces of elastic substrate and polarized along their thickness directions which are indicated in figure 1(c) by purple arrows. In this research, PZT plates from Fuji Ceramics C-6 series are employed [13]. The material and geometric properties of the prototype motor are listed in table 1.…”

“…Nowadays, the most representative piezoelectric motors include single mode motor which exploits two bending modes with the same order number [4][5][6], and composite mode motor which utilizes two different types of vibrational modes, such as longitudinal-bending [6][7][8], longitudinal-torsional [9,10], and bending-torsional modes [11,12]. However, the working modes of existing piezoelectric motors are typically fixed and should be simultaneously excited [13][14][15][16][17][18][19][20]. Furthermore, the chosen vibrational modes can normally be electrically excited by only one method [21][22][23][24][25][26][27][28][29][30].…”