• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.669-675
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• 2003

Transducer for ultrasonic linear motor with symmetric and anti- symmetric modes was studied. The ultrasonic linear motor consists of two Langevin type piezoelectric vibrators that cross at right angles with each other in tip. In order to excite symmetric and anti-symmetric modes, the transducer must have a phase shift of 90 degree in space and time. As a result, the tip of transducer moves on an elliptical motion. In this paper, the finite element analysis was used to optimize dimension and displacement of the transducer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.959-960
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• 2012

• Transactions on Electrical and Electronic Materials
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• v.5 no.2
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• pp.61-65
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• 2004

Bolt-tightened Langevin type vibrators using longitudinal mode of bar were designed and fabricated. In order to amplify the displacement of the tip of the vibrators, stacked ceramics were used and five different shapes of the horns were designed and jointed. Resonant frequencies and vibration characteristics of vibrators and horns were analyzed by ANSYS(finite element analysis computer program), and the displacements of tips of the horns were measured. As results, when the numbers of the stacked ceramics were increased, the displacements of the tips were increased and the driving voltages were decreased. Step l horn (BLT-St1) showed maximum displacement of 36.92 $\mu\textrm{m}$ at 36.7 ㎑ with 45 V$\sub$rms/ and 0.11 A. The displacement amplification ratio was about 5.2. But, the stress of step l horn was concentrated on intersection, where two diameters meet. To lessen the stress, step3 shaped hem is recommended.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1197-1205
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• 2001

The vibrational characteristics of Langevin-type piezoelectric torsional transducers, which consist of a couple of piezoelectric discs and a couple of elastic blocks, have been studied theoretically and experimentally in this paper. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Solutions of the boundary-value problem have yielded the natural frequencies and mode shapes of the transducers. The theoretical solutions have been verified by comparing the numerical results with experimental ones.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.142-148
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• 2013

High-power ultrasonic promotes a chemical reaction by its own energy, thus it has been used for sonochemistry applications. For example, it has been mostly used for mixing, reaction catalyst, dispersion and disintegration. High-power ultrasonic transducer is made with structure based on a Bolt-clamped Langevin type Transducer (BLT), But it has difficulty in the development because degradation of piezoelectric ceramic by the heat generation of BLT. In this study, for a development of the transducer of 25 kHz and 1000 W used in sonochemistry and industrial cleaning, BLT with a hole in its center and tubular type waveguide of the transducer were designed based on finite element method (FEM). The transducer was fabricated based on the design parameter, and the impedance characteristics are measured experimentally and compared with the numerical results.

• Journal of KSNVE
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• v.10 no.6
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• pp.955-962
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• 2000

The paper deals with a theoretical study on the vibrational characteristics of piezoelectric torsional transducers. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration in several transducer types. Numerical results have clarified the effect of the piezoelectric phenomenon on the mechanical resonance and the effect of the elastic block of a Langevin-type transducer on the natural frequency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.664-668
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• 2003

Transducer for ultrasonic linear motor with the symmetric and anti-symmetric modes was studied. The ultrasonic linear motor consists of two Langevin type piezoelectric vibrators that cross at right angles with each other in tip. In order to excite symmetric and anti-symmetric modes, the transducer must have a phase shift of 90 degree in space and time. Therefore, the tip of transducer moves on an elliptical motion. In this paper, the finite element analysis was used to optimize dimension and displacement of the transducer. The ultrasonic motor was fabricated using the simulated result and the driving characteristics were measured. No-load velocity was 0.28[m/s] and the maximum efficiency was 30[%] in resonance frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1280-1285
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• 2000

The paper deals with a theoretical study on the vibrational characteristics of piezoelectric torsional transducers. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration in several transducer types. Numerical results have clarified the effect of the piezoelectric phenomenon on the mechanical resonance and the effect of the elastic block of a Langevin-type transducer on the natural frequency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.223-227
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• 2003

In this study, ultrasonic rotary motors using a bolted langevin type ultrasonic vibrator were designed and fabricated. The stator vibrator has a longitudinal transducer section composed of two metal blocks and two piezoelectric ceramic elements (thickness-polarized) and a mode conversion metal block section called a torsion coupler. And, three kinds of motors were studied by finite element analysis and experiments. So, as material of torsion coupler which generate mode conversion of vibration copper, brass, and phosphor bronze were used. As a result, speed and torque were changed in proportion to the electrical input Voltage, but it was saturated in high voltage. And bad efficiency which was different from a expectation was measured in this motors. So, various problems should be improved for practical use. Finally, The motor which has 1 [cm] diameter was fabricated to present a possibility of miniaturization of this type motors.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.1 s.106
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• pp.89-100
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• 2006

This paper presents an analytical approach to describe the variation in the vibration characteristics such as the natural frequency of a piezoelectric transducer under static pre-pressure. The transducer considered in this paper is a bolt-clamped Langevin-type transducer, which consists of a couple of piezoelectric discs, a couple of metal blocks for added mass effect, and a bolt to tighten them. A new analysis model for the transducer has been developed by taking into account the contact area between the piezoelectric ceramic disc and the metal block. The variation of the resonance frequency due to the pre-pressure has been calculated and compared with measured results reported earlier.