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Driving Characteristics of a Thin Square Frame-type Ultrasonic Motor
박충효,정성수,박태곤 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.6
A thin, square, frame-type ultrasonic motor was proposed for applications in small actuators. The stator is easy to fabricate because of the simple structure where eight piezoelectric ceramics are attached on the thin square frame-shaped elastic body. When two sinusoidal sources with a phase difference of 90 degrees are applied to the stator, elliptical displacements are generated at the four edges of the stator. The designed rotor is revolved by the displacements. A finite element method was used to simulate the generated displacements, and a driving experiment was then conducted to compare the output characteristics with the results of the simulation.
박충효,김종욱,정성수,정현호,김명호,박태곤,Park, Choong-Hyo,Kim, Jong-Wook,Jeong, Seong-Su,Chong, Hyon-Ho,Kim, Myong-Ho,Park, Tae-Gone 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.1
On this paper, a circular unimorph-type piezoelectric transducer was proposed and studied. The transducer was fabricated by attaching a circular-shaped PZT ceramic to a circular plate of brass and output characteristics of the fabricated transducer were then analyzed and measured by changing driving points where the mechanical vibrations were applied. Two conditions depending on the location of vibration were respectively defined as a center forced model and an edge forced model. The resonance frequency and output voltage of the models were simulated by using ANSYS, a FEM(finite element method) program. Based on the results of the analyses, the vibration experiment was conducted and the output characteristics then measured through measurement equipment. As a result, the maximum output characteristics of two models were respectively generated at each resonance frequency and the resonance frequency of the center forced model was lower than the edge forced model.
방과 후 12주간 자율체육활동이 남자고등학생의 체력과 신체적 자기개념에 미치는 영향
박충효(Chung Hyo Park),변재철(Jae Chul Byun),류호상(Ho Sang Yoo) 한국발육발달학회 2006 한국발육발달학회지 Vol.14 No.4
The purpose of this study was to determine the effects of after-school physical activity on fitness and physical self-concept in male high school students. A total of 120 high school male students were randomly assigned to either experimental group (n=60) or control group (n=60). The experiment all group participated in one intramural sports activity either (soccer, basketball or badminton) for ninety minutes three times a week (Monday, Wednesday and Friday) during twelve weeks. Analysis of covariance (ANCOVA) using pre-test score as a covariant showed that the experimental group was significantly better than the control group in 50m running push up, sit up, standing long jump, sit and reach, 1600m running (p<.001). Health, regular exercise, muscle strength, confidence, sustaining power of the physical self-concept were higher in the experimental group compared to the control group. It was concluded that the participation of intramural sports have positive effects on physical fitness and physical self-concepts in male high school students.
재질 및 사이즈 변화에 따른 심벌타입 압전 트랜스듀서의 발전특성
박충효(Choong-Hyo Park),김종욱(Jong-Wook Kim),정현호(Hyon-Ho Chong),정성수(Seong-Su Jeong),김명호(Myung-Ho Kim),박태곤(Tae-Gone Park) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.7
Generating characteristics of cymbal type piezoelectric transducer depending on changes in materials and thickness of elastic bodies were studied. Cymbal type piezoelectric transducer is well known model in the piezoelectric transducer fields. Particularly, the transducer has good characteristic for stress of low frequency. Shape of the transducer is that the elastic bodies of cymbal type are attached to upper and bottom of the piezoelectric ceramic. The principle of generation is to generate larger displacement of the ceramic because applied vertical stress is transformed into horizontal stress by slope angle of the elastic bodies. This study was based on the previous study on generating characteristics of cymbal type transducer depending on shape of the cymbal cap. To define generating characteristic depending on changes in materials and thickness, simulation was performed by FEM program. From the simulation, the model of high efficiency could be chosen.
김종욱,박충효,임정훈,정성수,김명호,박태곤,Kim, Jong-Wook,Park, Choong-Hyo,Lim, Jung-Hoon,Jeong, Seong-Su,Kim, Myong-Ho,Park, Tae-Gone 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.9
A novel design of a simple square-frame USM (ultrasonic motor) was proposed. The stator of the motor consists of a square-frame shape elastic body and four rectangular plate ceramics. The four ceramics were attached to inner surfaces of the square frame elastic body. The same phase voltages were applied to the ceramics on horizontal surfaces, and 90 degree phase difference voltage were applied to the ceramics on vertical surfaces. To find a model that generates elliptical motion at outside of the stator, the finite element analysis program ATILA was used. The analyzed results were compared to the experimental results. As result, the model EL10EH3ET0.5CL4 which generates the maximum elliptical displacement was chosen by analyzing the resonance mode according to changes in frequency.
김종욱,박충효,정현호,정성수,박태곤,Kim, Jong-Wook,Park, Choong-Hyo,Chong, Hyon-Ho,Jeong, Seong-Su,Park, Tae-Gone 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.7
In this paper, the characteristics of a thin-type ultrasonic motor generating elliptical displacements analyzed by FEM are presented, and then fabrication of the motor is then described. The structure of the motor consists of sixteen ceramic pieces attached to the upper and bottom surfaces of an elastic body. The principle of the motor is to apply alternating voltages which have a 90 phase difference to the attached ceramics, and then elliptical displacements are generated at four edges of the elastic body. Then the rotor is moved by the elliptical displacements. In the case of a ceramic thickness of 1.5, the highest speed was obtained at 79 kHz. In the case of a ceramic thickness of 2 mm, the highest speed was obtained at 77.5 kHz. Consequently, the speed and torque of the ultrasonic motor (USM) increased linearly with increasing applied voltage.
정성수,박충효,강신출,김종욱,임정훈,김명호,박태곤,Jeong, Seong-Su,Park, Choong-Hyo,Kang, Shin-Chul,Kim, Jong-Wook,Lim, Jung-Hoon,Kim, Myong-Ho,Park, Tae-Gone 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.11
A cantilever-type piezoelectric generator has advantages of simple structure, ease of fabrication and large displacement by transverse vibration of a beam. It is easy to control the natural frequency, and also possible to increase the output power by changing the length, width, and thickness of the generator. In particular, the length increases, the natural frequency sharply decreases, and vice versa. Hence, the natural frequency can widely be controlled by using change in the length of elastic body. In this paper, the generator was designed and fabricated to change natural frequency using the slides of the case. In addition, the generating characteristics were confirmed through finite element analyses and vibration experiment. As a result, the maximum output characteristics could be generated due to resonance phenomenon although any frequency of external force was applied.
김종욱(Jong-Wook Kim),박충효(Choong-Hyo Park),정성수(Seong-Su Jeong),정현호(Hyon-Ho Chong),박태곤(Tae-Gone Park) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.7
In this study, a coupled standing wave-type ultrasonic motor is proposed and analyzed. A prototype of the motor was fabricated by using a v shaped SUS stator which consist of two ceramic pieces attached on upper surfaces. Principle of the motor is to apply alternative voltages which have 90 phase difference to attached ceramics, and then elliptical displacement is generated at tip of stator. As a result, the slider was driven by frictional force and the revolving direction of tip is same to slider direction. To obtain analysis result, FEM(finite element method) was used by ATILA 1.4.5. Design Variables is chosen as the size of the stator and ceramics. The arm, leg and angle of fabricated motor is 6 [㎜], 7 [㎜] and 75°, 95° respectively. A deformation amplitude of about 0.16 [㎛] can be obtained by applying a 70 [V] voltage. Likewise, maximum speed of the motor represent 0.08 [㎧] at 70 [V] voltage.