• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.10
• /
• pp.484-490
• /
• 2003

This paper describes with the stator analysis and design of a ring type ultrasonic motor. The design for piezoelectric ceramic and elastic body of stator were calculated by using the finite element method (FEM) that consider the resonance frequency, vibration mode and coupling efficiency. Namely, such results were acquired the calculation result of the piezoelectric ceramic thickness 0.5[mm], elastic body thickness 2.0[mm], resonance frequency 51.8[kHz], vibration mode 7 order and coupling efficient 12.5[%], the outer and inner diameter of vibrator 50[mm], 38[m]. On the basis of such result, the ring type ultrasonic motor was manufactured. Also for driving characteristics of ring type ultrasonic motor, 2-phase inverter was constructed. Then the propriety of this paper was established from comparision of the simulation and an experiment results of the ring type ultrasonic motor.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.3B no.4
• /
• pp.173-178
• /
• 2003

The rotational force of ultrasonic motors is able to get from the frictional force of elliptical vibration by contact between rotor and stator. Generally, ultrasonic motors are suitable for driving at resonant frequencies of about 20∼80［KHz］. The driving characteristics of ring type ultrasonic motors are the object of this study. A two-phase driving signal is delivered to the tested ultrasonic motor, which has a $90^0$ phase difference respectively with both sine and cosine voltage waveforms. The driving frequency is almost equal to the mechanical resonant frequency for the proper operation, and the driving signal is supplied by the two-phase parallel resonant inverter. The validity of the proposed driving method is verified by experimental results with stable operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.674-677
• /
• 2002

In this paper, two kinds of windmill type motors which have a disk shape and a ring shape piezoelectric ceramics were studied. And characteristics of two models were compared with each others. A windmill type ultrasonic motor is composed of a stator, a rotor, and a ball bearing. The stator is made of a piezoelectric ceramics and two metals endcaps. When the piezoelectric ceramics vibrate, displacement of torsonal vibration appear at metal endcaps. The motor with 11.0[mm] diameter was studied by finite element analysis. The voltage of 100[V] was supplied at each model. Resonance frequency of 206.875[KHz] was obtained at the disk type, but ring type was 137.562[KHz]. The maximum torsonal displacement of $1.112[{\mu}m]$ was obtained at the disk type, but ring type was $1.698[{\mu}m]$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.305-308
• /
• 2002

This paper presents design and analysis of stator which is vibration source of ring-type ultrasonic motor. The stator were designed for 9th flexural vibration mode. Designed stator was simulated by FEA for changing its materials. As results, the resonance frequencies of stators were changed by Poisson's ratio and density. And higher displacement were obtained by using the materials of low Young's modulus. Using the results, can easily design and manufacture the stator of ring type ultrasonic motor. And we suppose that it can save the time and finances.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.184-187
• /
• 2000

In this paper, a ring-type ultrasonic motor divided into 12 sectors was modeled by Atila program using finite element method(FEM). The stator consists of a piezoelectric ceramic poled alternately in opposite directions and elastic material. And the stator dimension was $\Phi$40 (outer diameter), $\Phi$ 30(inner diameter), 0.5mm(ceramic thickness) and 3mm(elastic material thickness). As a simulation result, 6$\lambda$ displacement occurred at approximately 52kHz, and this resonance frequency is similar to calculated result 57kHz. The position of maximum displacement was at the edge of stator.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.5
• /
• pp.309-317
• /
• 2004

This paper suggested the vibration characteristic improvement by variation mode of ring type ultrasonic motor. Design for the piezoelectric ceramic and elastic body of stator were calculated by the finite element method(FEM) that consider the resonance frequency, vibration mode and coupling efficiency etc. Through the result of vibration analysis from 6 order mode to 8 mode, the 7 order mode was gained very an excellent results that it was the coupling efficient, minimum power loss and bending vibration value. Here over 7 order mode, this paper was acquired that an output current for input voltage was very a large increased results. The result of vibration calculation, from thickness 0.5[mm] to 2[mm], knew the fact that the vibration displacement at 0.5[mm] is an high value too. From such result, this paper was manufactured the ultrasonic motor of outer diameter 5O[mm] , inter 22[mm] having the about 43.86[KHz] resonance frequency. We have gated that a simulation result is 42.2[KHz] and an experiment result is 43.86[KHzl The propriety of this paper was established though comparison. investigation of simulation and experiment result.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.729-731
• /
• 2003

This Paper describes for vibration characteristic analysis by mode variation of ring type ultrasonic motor. Design for piezoelectric ceramic and elastic body of stator was calculated by Atila using the finite element method(FEM) that considers the resonance frequency, vibration mode and coupling efficiency etc. The propriety of this paper was established through simulation and experiment results of ring type ultrasonic motor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.27 no.5
• /
• pp.286-291
• /
• 2014

In this study, novel ultrasonic rotary motor of hexadecagon shape stator was proposed. Stator of the hexadecagon ultrasonic motor was composed of an elastic ring and ceramics. The elastic ring had sixteen sides and sixteen angular points. Eight ceramics were attached on the outer surface of the eight sides of the ring. When rotor of cylindrical shaft was inserted inside of the ring stator, central lines of the sixteen sides of the stator hold the shaft by the slight pressures(frictions). This slight pressure was a preload of the motor and it could be controlled by radius and thickness of the ring. When two sinusoidal voltages which have 90 degree phase difference were applied to each four ceramics, elliptical displacements of inner surface of the ring were obtained. These elliptical displacements of the inner surface rotated the shaft rotor through the frictions. The proposed hexadecagon ultrasonic motor was designed and analyzed by using the finite element method (FEM), depending on materials of the elastic ring. Based on the FEM results, one model of motor which showed maximum displacement at contact points was chosen and fabricated. And characteristics of the motor were compared with simulated results. When the motor was fabricated with these results, EL20ET0.5CT0.5CW2 model showed 115[rpm] speed about input voltage of 60[Vrms] at 65.6[kHz]. And the maximum torque of 6[gfcm] was obtained. From these results, the hexadecagon shaped ultrasonic motor can be used to actuator for optical device which needs detailed position control. Also it can be used to medical and portable device by reducing size and weight.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.321-321
• /
• 2010

In this paper, we propose a novel type shaft-less ring type ultrasonic motor. A traveling wave rotary type ultrasonic motor is selected as a base model. The newly designed stator has two piezoelectric ceramic rings which are bonded in sandwich shape as traveling wave generator. So, we can expect to produce higher torque. The proposed model has the rotor structure that coupled with the stator provokes the pressure, this model do not install the separate plate any spring device. We used the finite element method to verify the operation principle and to compute the vibration mode of proposed model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.181-183
• /
• 2000

Ultrasonic Motors of Wind-Mill type(diameter in 11.35mm, thickness in 2.8mm, and 1.44g weight) using Piezoelectric Ceramics have been developed. In recent study, Maximum torque in 100$V_{max}$, 105.8kHz was 7.2 ${\mu}$N$.$m, and bidirectional revolution using single-phase AC was presented. However, it is difficult to use because of small torque. Thus, in present study, new type of Wind -Mill Type Ultrasonic Motor of was designed as stator' structure was changed