This paper describes a new multi-degree-of-freedom (MDOF) ultrasonic motor that comprises few parts and is based on low-cost thick-film technology. Conventional motors using bulk lead zirconate titanate (PZT) or thin-film PZT layers are relatively expensive at the present time. Thick-film printed technology provides opportunity to reduce costs of motors. To demonstrate feasibility this approach, an was fabricated from alumina actuators. The electrode were thin plate, tiny cylinder mounted...

Abstract This study investigates a scheme utilizing ring transducer for an acoustic underwater propulsion system. Acoustic systems are well suited the inspection and repair of robots due to their small size, high power density, simple structure. Previous research has focused on self-propelled swimmers disc transducers. However, radial vibration component transducers makes it difficult provide system driven by driving force. Pure longitudinal requires greater thickness achieve same area,...

The present paper deals with some ultrasonic motors using longitudinal and bending multimode vibrators their mode couplings caused by externally additional asymmetry or internal nonlinearity. A rectangular plate vibrator two corners on one diagonal line cut to make its resonance modes couple each other was used, along a under the condition that frequencies are obtained, for example, as f L / B =2.0, because nonlinear coupling of parametric vibration between is generated this condition. Using...

A sandwich-type multidegree-of-freedom (MDOF) spherical ultrasonic motor (SUSM) is newly proposed. The consists of a rotor and two stator vibrators holding the rotor. This structure has both support preload mechanism. excites five vibration modes, can rotate on three axes. An experiment torque composition stators was carried out. contact surface between forms surface. Moreover, displacement magnification mechanism, which used in former model to Z -axis, no longer necessary. Hence simpler...

Abstract Acoustic underwater propulsion systems based on an ultrasonic transducer have been studied. In previous research, the self-propelled acoustic swimmer using thickness-vibration-mode is evaluated widely. The excited in thickness and radial direction. Because system driving force, vibration direction hard to provide thrust. this study, a cylindrical transducer, pure longitudinal vibrator, for system. A prototype with multiple transducers designed fabricated. admittance characteristics...

Ultrasonic motors using longitudinal and torsional motions of rod vibrators have previously been proposed. Several motor constructions, whose forms are different from the previous ones, proposed their characteristics experimentally examined in order to develop ultrasonic this type; that is, they expected much uses, according how modified. Two groups dealt with: one contains basically suited relatively high torque 2-3 kgf-cm other for small or medium below about 1.0 kgf-cm. As result,...

A miniature thin-plate ultrasonic motor fabricated from LiNbO3 was studied. To obtain a single phase drive motor, we used coupling mode which combined longitudinal and flexural in-plane vibrations. In our previous study, the modes were achieved in parallelogram vibrator by effect of additional external mass. Instead deforming outer shape, this study uses an internal resulting crystal anisotropy. We confirmed that rectangular plate made X-rotated Y-cut with y'-axis rotation has can operate as...

Spherical ultrasonic motors (SUSMs) that can operate with multiple degrees of freedom (MDOF) using only a single stator have high holding torque and at low speed, which makes reduction gearing unnecessary. The simple structure MDOF-SUSMs them useful as compact actuators, but their development is still insufficient for applications such joints humanoid robots other systems require MDOF torque. To increase the sandwich-type MDOF-SUSM, we not made vibrating spherical rotor larger also improved...

Acoustic underwater propulsion systems based on bulk acoustic waves and surface have been studied. In this study, an system that consists of a 2.065-MHz thickness-vibration-mode lead-zirconate-titanate ultrasonic transducer is evaluated. A prototype swimmer designed fabricated. The admittance difference the in water air investigated. vibration amplitude measured to evaluate performance. radiation force calculated describe propulsion. zero-speed (ZSP) no-load speed (NLS) are water. Swimmer...

Acoustic propulsion system presents a novel underwater approach in small scale swimmer. This study introduces submerged surface acoustic wave (SAW) based on the SiO2/Al/LiNbO 3 structure. At 19.25 MHz, SAW is proposed and investigated by force calculation, PIV measurements measurements. 3.3 mN measured at 27.6 Vpp. To evaluate miniature swimmer, systems with multiple frequencies are studied. 2.2 W, 38.45 MHz demonstrates 0.83 mN/mm2 characteristics. 96.13 24 Vpp, movements of swimmer fully...

Dielectric loss in a piezoelectric ceramic transducer is related to the vibration, and increases markedly under high-power operation. When PZT ceramics used over vibration velocity of about 0.25 (m/s), dielectric becomes larger than mechanical loss. In this paper, values resistances indicating equivalent circuit are shown. If an electric including these utilized, efficiency transducers operating at level may be calculated with more accuracy. By calculation efficiency, maximum was obtained...

The holding of a levitated object above stator vibrators by utilizing the force, which is generated near-field acoustic levitation, possible. force yields at edge vibration plate and nodes bending mode, it in proportion to amplitude plate. In this paper, we describe methods transfer positioning many aligned vibrators, some experimental results, proposition application as noncontact-stepping ultrasonic motor (NCS-USM). Linear-type rotary-type NCS-USMs can be flexibly constructed. NCS-USM has...

As an application of noncontact transportation utilizing the near-field acoustic levitation phenomenon, a rotary-type noncontact-synchronous ultrasonic motor (NCSyn-USM) using viscous force was examined. The NCSyn-USM consisted six fan-shaped stators arranged in circle and flat rotor installed above via small air gap. possibility investigated by both numerical simulation measurement. From acoustic-structure fluid-structure interaction analyzes finite element method, correlation between sound...

The holding force acting on a levitated object during near-field acoustic levitation has not been statically and directly measured so far. In this study, it was considered to realize such measurement when large displacement from the vibration source. previous studies, under restricted conditions, calculated indirectly by image processing or balance with gravity tilting apparatus. article, based magnetic (MF) compensation principle. This is first attempt measure arbitrary conditions. One side...

In this paper, we report an ultrasonic motor capable of high-velocity revolution applicable for long continuous high operation as a microfan. This study is response to the new challenge developing field applications motor. Ultrasonic motors using longitudinal-flexural coupling-vibration mode thin plate with vibrating piece or step-horn are considered. A stator vibrator consists metal sandwiched by two unipoled piezoelectric ceramic plates, electrodes which not divided, and can be driven...

A multidegree-of-freedom (MDOF) ultrasonic motor using the multimode of a disk vibrator is realized. spherical rotor can rotate around arbitrary axes. However, at beginning research on MDOF motor, did not have any mechanisms for supporting rotor. Since preload was given by only rotor's own weight, friction between and stator very small, but torque characteristics were insufficient practical use. The purpose this study to improve performance further. In paper, some support plate examined...

The holding force acting on a levitated object in near-field acoustic levitation apparatus was examined an effort to increase between opposing vibration sources. Using finite element analysis, we calculated levels generated by vertically opposed sources and found that when the phase difference of 180°, level larger than could be produced single source. On other hand, is 0°, radiation surfaces decreased. Additionally, increased against decrease distance surfaces. This experimentally confirmed...

Abstract A multidegree-of-freedom ultrasonic motor (MDOF-USM) has excellent features such as high torque at a low speed and self-holding force, compared with other types of MDOF motor. Therefore, the MDOF-USM been considered for applications in robot joints, multidimensional systems, spacecraft. In previous research, consisting spherical rotor stator vibrator various shapes mainly studied. contrast, is proposed this paper. The excitation methods vibration modes mode rotation using...

Abstract A non-contact transport method using near-field acoustic levitation has been studied. In this research, the levitated object is transported by multiple stators in steps. This requires a large number of stators, but it advantage precisef positioning because stopped and held on each stator. addition, arranging two dimensions, transportation two-dimensional direction realized, stable operation not obtained, such as unintended rotation transportation. Through experiments analysis, we...