Rotary Type Ultrasonic Motor Research Articles

Performance analysis and experimental study of traveling wave type rotary ultrasonic motor in high-rotation environment.

In this work, the performance evolution of a traveling wave type rotary ultrasonic motor (TRUM) in a high-rotating environment is studied. The dynamic model of the stator of the TRUM in the centrifugal field is established, and the centrifugal stiffening effect on the stator caused by the centrifugal force is described. Furthermore, the warping deflection of the stator caused by the centrifugal force is analyzed. It is found to change the original contact state and decrease the performance of the TRUM. The contact model between the stator and rotor in the centrifugal field is established. Moreover, the performance model of the TRUM in the centrifugal field is established, and the mechanism and varying trend of the mechanical performance of the TRUM in this condition are analyzed. Finally, the performance test system of the TRUM is set, and the mechanical performance of the TRUM at high angular velocities environment is measured. And the methods to improve the tolerance of the TRUM in the centrifugal field are put forward.

A rotary type ultrasonic motor using Langevin transducers.

A rotary type ultrasonic motor using Langevin transducers.

Design and Characteristics of a New Thin Cross Type Rotary Ultrasonic Motor

A new thin cross type rotary ultrasonic motor has been proposed for further study of this type motors characteristics. As a stator, eight semi-circular piezoelectric ceramics were attached on the upper and bottom sides of a thin hollow cross brass plate. The stator was excited by two sinusoidal voltages with a phase difference of 90° and elliptical trajectories were generated at the contact points to drive a shaft rotor. The driving principle of the motor was illustrated by degenerating two orthogonal in plane vibration modes. Based on FEM analysis, the vibration shapes and frequencies of operation modes were simulated and the relationships between the maximum displacements of the contact points and various motor parameters were obtained. A prototype was fabricated and characteristics of the motor were measured. The relationship among rotation speed, pre-pressure and voltage are no-linear. The maximum rotation speed with no load was 22.9 rpm. The merits and shortcomings of the thin cross type rotary ultrasonic motor were discussed.

Study on the Ring Type Stator Design Technique for a Traveling Wave Rotary Type Ultrasonic Motor

Study on the Ring Type Stator Design Technique for a Traveling Wave Rotary Type Ultrasonic Motor

Study on the Ring Type Stator Design Technique for a Traveling Wave Rotary Type Ultrasonic Motor

In this paper, the technique of design for the stator of traveling wave rotary type ultrasonic motor was proposed. To establish the design technique, the distribution of internal stresses of the stator was analyzed by applying the cylindrical bodies contact model of Hertz theory and the concept of “horn effect” was used to consider the influence of the projection structure. To verify the proposed technique, the prototype motor was fabricated on the authority of the projection shape dimension and the design specification. And its performance was evaluated. According to the estimate production of the experiment results using the extrapolation, we confirmed that the values obtained through the verification experiment were similar to those deduced by the proposed method properly.

Analysis and Design of Stator of Traveling Wave Type Rotary Ultrasonic Motor

Due to its compact sizing, fast response and good control performance traveling wave type rotary ultrasonic motor (TRUM) has significant potentials for applications in robot actuation. In order to considering the complex geometries, this paper presents modeling approach for micro-TRUM stator. First piezoelectric composite stator is partitioned into three substructures, two of which are modeled as several continuous annular plates by semi-analytical method. Without losing the complex geometries, the stator teeth as another substructure are modeled by means of finite element (FE) approach. Based on both component-mode synthesis and dynamic reduction, the coupled method for continuous plate and FE discretized teeth is presented in order to consider dynamic behavior of composite stator with good accuracy and short computation time. It allows combination of the continuous parameters and FE discretized substructures, and the mathematical model representing the complete stator is derived. Finally the prototype is manufactured according to the presented method. The validation of the analysis and design method is attained through the experiments for the manufactured stator. It is pointed that radial friction can be capable to increase s for the ultrasonic motor with smaller dimension. It explains why micro-TRUM has a fast heat output at the contact interface.

Fabrication and Characteristics of Ring Type Valveless Piezoelectric Micro-Pump using Peristaltic Motion

The operation principle of travelling wave rotary type ultrasonic motor can be applied to fluid transfer mechanism of micro-pump successfully. In this paper, we propose a novel type valveless micro-pump that uses extensional vibration mode of travelling wave as a volume transporting means. The proposed pump consists of coaxial cylindrical shells that joined piezoelectric ceramic ring and metal body respectively. In accordance with the variation of the pump body dimension, we analyzed the vibration displacement characteristics of pump model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its performance. The maximum flow rate was about 530 μl/min and the highest back pressure was 0.83 kPa at 120Vrms, 35 kHz input voltage.

Design of a Valveless Type Piezoelectric Pump for Micro-Fluid Devices

The operation principle of a traveling wave rotary type ultrasonic motor can be successfully applied to the fluidic transfer mechanism of the micro-pump. This paper proposes an innovative valveless micro-pump type that uses an extensional vibration mode of a traveling wave as a volume transportation means. The proposed pump consists of coaxial cylindrical shells that join the piezoelectric ceramic ring and metal body, respectively. In order to confirm the actuation mechanism of the proposed pump model, a numerical simulation analysis was implemented. In accordance with the variations in the exciting wave mode and pump body dimension, we analyzed the vibration displacement characteristics of the proposed model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its performance. The maximum flow rate was approximately 595 μL/min and the highest back pressure was 0.88 kPa at an input voltage of 130 Vrms. We confirmed that the peristaltic motion of the piezoelectric actuator was effectively applied to the fluid transfer mechanism of the valveless type micro pump throughout this research.

Research on the Three-Dimensional Elliptical Motion of Rotary Traveling Wave Ultrasonic Motor

The model of a particle on the stator tooth side of traveling wave type rotary ultrasonic motor is established based on the plate theory, which shows that trajectories of particles on the surface of the stator teeth are essentially three-dimensional Oblique elliptical motion. Take the RTUM60 type ultrasonic motor as an example, the three-dimensional elliptical motion of stator tooth’s endpoint is studied through numerical experiments, and the results show the energy loss caused by the radial sliding between stator and rotor is considerable. The influences of tooth height on effective elliptical motion, the velocity in the three direction under Cylindrical coordinate system and radial slip are also discussed, which conclude that the model can be used for further study on the contact model design and optimization traveling wave type ultrasonic motor.

Design of valveless type piezoelectric pump for micro-fluid devices

The operation principle of travelling wave rotary type ultrasonic motor can be applied to fluidic transfer mechanism of micro-pump successfully. In this paper, we propose a novel type valveless micro-pump that uses extensional vibration mode of travelling wave as a volume transporting means. The proposed pump is consisted of coaxial cylindrical shells that joined piezoelectric ceramic ring and metal body respectively. To confirm the actuation mechanism of proposed pump model, a numerical simulation analysis on the proposed model was implemented. In accordance with the variation of exciting wave mode and pump body dimension, we analyzed the vibration displacement characteristics if proposed model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its performance. The maximum flow rate was about 580[μl/min] and the highest back pressure was 0.85[kPa] at 120[Vrms] input voltage. We confirmed that peristaltic motion of piezoelectric actuator was able to be applied to the fluid transferring mechanism of valveless type micro pump effectively through this research.

Effect of flexible rotor on performance of traveling wave type ultrasonic motor

First the definition of flexible rotor of traveling wave type rotary ultrasonic motor (TRUM) is given.It is pointed out that the flexible rotor can be classified in the range of elastic annular plate with large overall motion.And the kinematical equation of flexible rotor is derived.Then the rigid-flexible coupling dynamic model of flexible rotor is obtained by Lagrange equation.So the complete model of TRUM is derived by the integration of the contact model based on flexible rotor,stator's semi-analytical model and flexible rotor model.The analysis examples show that the complicated contact mechanism with asymmetry occurs at the inter- face between the stator and flexible rotor.The analyses explain how the appropriate damp of rotor can lead to the good performance of motor.Moreover the proper flexible rotor is proved to improve the motor's output efficiency by decrease of the friction in the ra- dial direction at the interface.Finally the results of simulation are found to be in good agreement with those of experiments,so the proposed model provides the theoretical foundation for the design of the flexible rotor.

P2-30 A Novel Semi-analytical Model of the Stator of the Traveling Wave Type Rotary Ultrasonic Motor Based on Dynamic Substructure Method(Short oral presentation for posters)

P2-30 A Novel Semi-analytical Model of the Stator of the Traveling Wave Type Rotary Ultrasonic Motor Based on Dynamic Substructure Method(Short oral presentation for posters)

Rotary Ultrasonic Flat Motor

Using the longitudinal and flexural vibrations of a plate a new type rotary ultrasonic motor has been realized. This motor has low-speed and high-torque equal to one using longitudinal and torsional vibration. It also has many advantages of miniaturization and lower cost.