共查询到20条相似文献,搜索用时 31 毫秒
1.
Elastic contact conditions to optimize friction drive of surface acoustic wave motor 总被引:2,自引:0,他引:2
Kuribayashi Kurosawa M Takahashi M Higuchi T 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1998,45(5):1229-1237
The optimum pressing force, namely the preload, for a slider to obtain superior operation conditions in a surface acoustic wave motor have been examined. We used steel balls as sliders. The preload was controlled using a permanent magnet. The steel balls were 0.5, 1, and 2 mm diameter, with the differences in diameter making it possible to change contact conditions, such as the contact pressure, contact area, and deformation of the stator and the slider. The stator transducer was lithium niobate, 128 degrees rotated, y-cut x-propagation substrate. The driving frequency of the Rayleigh wave was about 10 MHz. Hence, the particle vibration amplitude at the surface is as small as 10 nm. For superior friction drive conditions, a high contact pressure was required. For example, in the case of the 1 mm diameter steel ball at the sinusoidal driving voltage of 180 V(peak), the slider speed was 43 cm/sec, the thrust output force was 1 mN, and the acceleration was 23 times as large as the gravitational acceleration at a contact pressure of 390 MPa. From the Hertz theory of contact stress, the contact area radius was only 3 mum. The estimation of the friction drive performance was carried out from the transient traveling distance of the slider in a 3 msec burst drive. As a result, the deformation of the stator and the slider by the preload should be half of the vibration amplitude. This condition was independent of the ball diameter and the vibration amplitude. The output thrust per square millimeter was 50 N, and the maximum speed was 0.7 m/sec. From these results, we conclude that it is possible for the surface acoustic wave motor to have a large output force, high speed, quick response, long traveling distance, and a thin micro linear actuator. 相似文献
2.
Iula A Pappalardo M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2006,53(7):1344-1351
In the present work, a traveling wave ultrasonic motor (TWUSM) is proposed. It is composed of an annular-shaped stator and two cone-shaped rotors that are pressed in contact to the borders of the inner surface of the stator. A rotating traveling wave has been generated in the stator by using as vibration generators two bolted Langevin transducers (BLT) opportunely shifted in space and in time. The vibrational behavior of the stator as well as the traveling wave generation has been simulated with the finite-element method (FEM) software. A prototype of the motor has been manufactured and experimentally characterized. It exhibits a static torque of about 0.8 N x m and a maximum angular speed of about 300 rpm. Possible variations of the present design aimed to increase output torque or minimize encumbrance are described and discussed. 相似文献
3.
Morita T Kurosawa MK Higuchi T 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1999,46(4):929-934
The operation of a surface acoustic wave (SAW) motor using spherical-shaped sliders was demonstrated by Kurosawa et al. (1994). It was necessary to modify the previous simulation models for usual ultrasonic motors because of this slider shape and the high frequency vibration. A conventional ultrasonic motor has a flat contact surface slider and a hundredth driving frequency; so, the tangential motion caused by the elasticity of the slider and stator with regard to the spherical slider of the SAW motor requires further investigation. In this paper, a dynamic simulation model for the SAW motor is proposed. From the simulation result, the mechanism of the SAW motor was clarified (i.e., levitation and contact conditions were repeated during the operation). The transient response of the motor speed was simulated. The relationships between frictional factor and time constant and vibration velocity of the stator and the slider speed were understood. The detailed research regarding the elastic deformation caused by preload would be helpful to construct an exact simulation model for the next work. 相似文献
4.
A standing wave-type noncontact linear ultrasonic motor 总被引:4,自引:0,他引:4
Hu J Li G Chan HL Choy CL 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2001,48(3):699-708
In this study, a novel standing wave-type noncontact linear ultrasonic motor is proposed and analyzed. This linear ultrasonic motor uses a properly controlled ultrasonic standing wave to levitate and drive a slider. A prototype of the motor was constructed by using a wedge-shaped aluminum stator, which was placed horizontally and driven by a multilayer PZT vibrator. The levitation and motion of the slider were observed. Assuming that the driving force was generated by the turbulent acoustic streaming in the boundary air layer next to the bottom surface of the slider, a theoretical model was developed. The calculated characteristics of this motor were found to agree quite well with the experimental results. Based on the experimental and theoretical results, guidelines for increasing the displacement and speed of the slider were obtained. It was found that increasing the stator vibration displacement, or decreasing the gradient of the stator vibration velocity and the weight per unit area of the slider, led to an increase of the slider displacement. It was also found that increasing the amplitude and gradient of the stator vibration velocity, or decreasing the weight per unit area of the slider and the driving frequency, gave rise to an increase of the slider speed. There exists an optimum roughness of the bottom surface of the slider at which the slider speed has a maximum 相似文献
5.
A cylindrical traveling wave ultrasonic motor using a circumferential composite transducer 总被引:1,自引:0,他引:1
Liu Y Liu J Chen W 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(11):2397-2404
This paper intends to present and verify a new idea for constructing traveling wave ultrasonic motors that may effectively avoid the drawbacks of conventional traveling wave motors using bonded PZT plates as the exciting elements. In the configuration of the motor's stator, a composite sandwich type transducer is used to excite a traveling wave in a cylinder with two cantilevers as the coupling bridges between the transducer and the cylinder. The design process of the stator is described using the FEM modal analysis method, and the establishment of traveling wave on the cylindrical stator was simulated by FEM transient analysis. To verify the theoretical analysis results, a laser Doppler scanner was employed to test the mode shapes of a prototype stator excited by the longitudinal and bending vibrations respectively. Finally, to validate the design idea, a prototype motor was fabricated and tested; the typical output features are no-load speed of 156 rpm and maximum torque of 0.75 N·m under exciting voltages of 70 V(rms) applied to excite the longitudinal vibration of the transducer and 200 V(rms) applied to excite the bending vibration. 相似文献
6.
Yung Ting Liang-Chiang Chen Chun-Chung Li Jeng-Lin Huang 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(4):847-853
A new type of piezoelectric linear motor incorporating a traveling wave has been developed. The linear motor is comprised of a stator and a carriage. The stator design, which consists of a meander-line structure and gear teeth mounted on the meander-line structure, is the focus of this article. The meander-line structure is constructed with bimorph actuators arranged in a line. These actuators are driven by two phased sets of alternating current (ac) in order to generate a traveling wave. The traveling wave is transferred to the gear teeth, by which the carriage is driven. Modeling of the stator is derived by use of a strain energy method. The performance of various materials is evaluated by analytical and experimental methods. The analytical and the experimental results are quite approximate. Modal analysis is investigated using ANSYS. Appropriate modes associated with ultrasonic levels of resonant frequency are selected to obtain desired motion and to enhance the output performance. Surface speed for various applied input voltage are studied and indicate a nearly linear relationship. The stator in combination with the carriage makes up the linear motor 相似文献
7.
Asai K Kurosawa MK 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2005,52(10):1722-1734
This paper describes the air film characteristic in the interface between the slider and stator substrate of a surface acoustic wave (SAW) motor, and the difference of the squeeze film effect by the form of the slider. Because the vibration amplitude of the SAW motor is several 10 nm order, analysis of pressure was performed by using the molecular gas-film lubrication (MGL) equation. In the analysis, the MGL equation was split into advection phase and nonadvection phase, and calculation of advection and nonadvection phases was performed by using the cubic interpolated propagation (CIP) method and the finite difference method, respectively. From analysis results it was found that the time to steady pressure of air film depends on the radius of projection arranged on the contact surface of the slider. Also found was that the steady pressure in the interface does not depend on the radius and height of the projection, but it depends on the minimum spacing between the slider and the stator substrate. 相似文献
8.
Yung Ting Liang-Chiang Chen Chun-Chung Li Jeng-Lin Huang 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(4):847-853
A new type of piezoelectric linear motor incorporating a traveling wave has been developed. The linear motor is comprised of a stator and a carriage. The stator design, which consists of a meander-line structure and gear teeth mounted on the meander-line structure, is the focus of this article. The meander-line structure is constructed with bimorph actuators arranged in a line. These actuators are driven by two phased sets of alternating current (ac) in order to generate a traveling wave. The traveling wave is transferred to the gear teeth, by which the carriage is driven. Modeling of the stator is derived by use of a strain energy method. The performance of various materials is evaluated by analytical and experimental methods. The analytical and the experimental results are quite approximate. Modal analysis is investigated using ANSYS. Appropriate modes associated with ultrasonic levels of resonant frequency are selected to obtain desired motion and to enhance the output performance. Surface speed for various applied input voltage are studied and indicate a nearly linear relationship. The stator in combination with the carriage makes up the linear motor. 相似文献
9.
Koyama D Nakamura K Ueha S 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(11):2337-2343
Here we propose a self-running, ultrasonically-levitated sliding stage and investigate the levitation and propulsion characteristics of its stator. The stator consists of two aluminum beams and four PZT plates, which have two-paired bimorph configurations. A flexural standing wave was generated along the beam by applying an input voltage to the PZTs, and the stator could be levitated from a flat substrate by the acoustic radiation force generated by its own vibrating beam. The size of the stator was optimized using finite-element analysis (FEA) to maximize the vibration displacement amplitude of the beam. The flexural vibration modes at 24.3 and 102 kHz were the most prominent vibration modes having large displacement amplitudes. The stator was levitated at 23.2 and 96.1 kHz, which are close to the frequencies predicted by the FEA results. A standing wave was observed along the beam. The experimental and the simulated results showed good agreement. The levitation distance h was measured by varying the vibration displacement amplitude of the beam u, and was found to be proportional to u. When a traveling wave was excited along the beam by controlling the temporal phase difference of the two transducers, the stator could be made to hover and to move in the opposite direction to the traveling wave. The stator moved in the positive direction when the phase difference was in the ranges 0 degrees to 200 degrees and 310 degrees to 360 degrees, and in the negative direction when the phase difference was between 220 degrees and 260 degrees. 相似文献
10.
Friend J Nakamura K Ueha S 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2005,52(8):1343-1353
A 1.8 cc silent bidirectional traveling-wave, self-moving linear microactuator is shown to be capable of generating a sliding velocity of 0.22 m/s and sliding force of 1.1 N. Through the use of computational analysis in the actuator's design, the vibration characteristics were improved in order to obtain a better actuator. The generation of a radial traveling wave about the circumference of the actuator, akin to a ring, is shown to exist despite the unusual shape, and the presence of traveling wave motion along the output face also is shown to exist. By using short-time sinusoidal signals, slider displacements as small as 82 nm were obtained from the actuator, and by using direct current (DC) input, displacements of up to /spl plusmn/107 nm were obtained, suggesting a way to obtain subnanometer positioning accuracy over arbitrary sliding distances. By reversing the phase between the paired driving signals, the direction of motion was reversed at up to 300 Hz; the slider displacement and velocity was found to be inversely proportional to the phase-reversal rate, and the slider's peak velocity and maximum thrust force were directly proportional to the phase between the driving signals. The output force and velocity of the actuator was fairly insensitive to the input frequency, giving measurable motion between 132.5 and 141.5 kHz, but was sensitive to the input voltage, requiring at least 38 V input for operation, and was approximately quadratically dependent on the applied preload centered about 2.25 N. 相似文献
11.
Koyama D Ide T Friend JR Nakamura K Ueha S 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(3):597-604
This paper presents a noncontact sliding table design and measurements of its performance via ultrasonic levitation. A slider placed atop two vibrating guide rails is levitated by an acoustic radiation force emitted from the rails. A flexural traveling wave propagating along the guide rails allows noncontact transportation of the slider. Permitting a transport mechanism that reduces abrasion and dust generation with an inexpensive and simple structure. The profile of the sliding table was designed using the finite-element analysis (FEA) for high levitation and transportation efficiency. The prototype sliding table was made of alumina ceramic (Al2O3) to increase machining accuracy and rigidity using a structure composed of a pair of guide rails with a triangular cross section and piezoelectric transducers. Two types of transducers were used: bolt-clamped Langevin transducers and bimorph transducers. A 40-mm long slider was designed to fit atop the two rail guides. Flexural standing waves and torsional standing waves were observed along the guide rails at resonance, and the levitation of the slider was obtained using the flexural mode even while the levitation distance was less than 10 microm. The levitation distance of the slider was measured while increasing the slider's weight. The levitation pressure, rigidity, and vertical displacement amplitude of the levitating slider thus were measured to be 6.7 kN/m2, 3.0 kN/microm/m2, and less than 1 microm, respectively. Noncontact transport of the slider was achieved using phased drive of the two transducers at either end of the vibrating guide rail. By controlling the phase difference, the slider transportation direction could be switched, and a maximum thrust of 13 mN was obtained. 相似文献
12.
G. M��Boungui P. W. Loveday C. S. Long 《International Journal of Mechanics and Materials in Design》2011,7(1):45-53
The use of topology optimization in the design of a novel stator for an ultrasonic motor (USM) is investigated. The design
challenge is to produce a stator, with two resonant modes whose frequencies are in a ratio of 1:2. When driven together, these
modes result in a contact point trajectory in a figure of eight shape. As a result, only one electronic amplifier is required
to drive the proposed device. In contrast traditional travelling wave USM, with elliptical contact point trajectories, require
two modes with equal resonant frequencies to be driven 90° out of phase, and therefore require two amplifiers, one for each
mode. To achieve a suitable stator design, a slightly unconventional topology optimization problem formulation is proposed,
in which the objective function is to minimize the amount of material with intermediate density, while satisfying a constraint
related to the frequency ratio of selected resonant modes. The planar design produced using the optimization procedure was
refined using a detailed three dimensional finite element analysis. A prototype of the proposed stator design was manufactured
and experimentally characterized. Scanning laser vibrometry measurements from two positions were used to measure the figure
of-eight motion. Finally, the stator was fitted with a preloaded slider to form a simple linear motor demonstrator which was
characterized experimentally. The prototype motor produced a slider speed of 14 mm/s reversibly and a maximum force of 50 mN. 相似文献
13.
Lamberti N Iula A Pappalardo M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1998,45(1):23-29
This paper describes a new implementation of a disk-type piezoelectric motor, whose stator is a commercial available piezomembrane composed of a nickel alloy disk to which a piezoceramic disk is bonded. The two disks are concentric, and the total thickness is very small. Ultrasonic motors are based on the concept of driving a rotor by mechanical vibration excited on a stator, via the piezoelectric effect. The rotor is in contact with the stator, and the driving force is the frictional force between rotor and stator. To transform the mechanical vibration of the stator in the rotor rotation, a traveling wave must be excited on the stator surface. The proposed motor can be regarded as a disk-type, single wavelength motor in which the traveling wave is due to the natural flexural vibration of the piezomembrane at low frequency. The behavior of the stator is analyzed both theoretically, by using the theory of isotropic and homogeneous vibrating plates, and by means of a commercial finite element computer code, finding a good agreement with the experimental results. The main features of the motor are very small thickness, appreciable torque, and high speed, obtained with low input power at low voltage; the intended application is to substitute the moving-coil in analogic instrumentation. 相似文献
14.
二自由度行波型超声波电机是一种新型多自由度超声波电机。本文从二自由度行波型超声波电机的驱动机理和基本结构出发,就电机的结构实现、驱动球转子的最佳定子结构进行了分析,利用所建立的有限元模型进行定子振动的模态分析和共振频率计算,提出了外缘大倾角内缘线接触的行波定子。然后建立定子的接触模型,对其机械性能进行分析。测试结果表明,修正的数学模型更加符合电机的实际运行特性。所研制样机的球转子直径为45mm,定子直径为30mm,实现的堵转力矩为120mNm,空转转速12r/min。本文工作为多自由度行波型超声波电机的优化设计、性能提高奠定了基础。 相似文献
15.
旋转型行波超声电机定子的子结构模型研究 总被引:5,自引:0,他引:5
按照旋转型行波超声电机定子的结构特点将其划分为几个较简单的子结构,分别对其进行了动态特性分析,最后在子结构模态综合法的基础上建立了整个定子的分析模型。该模型可以很方便地计算电机定子的各阶模态,并且由于运用Guyan静力法将定子齿单元的刚度和质量凝聚到基体之上,不仅恰当地描述了齿对定子动态特性的影响,而且达到了缩减计算量的目的。通过算例和实验说明此理论模型是可行的,可用于电机系统性能预测和参数优化设计。 相似文献
16.
Shigematsu T Kurosawa MK 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2008,55(9):2005-2015
The surface acoustic wave motor in this study utilized transparent lithium niobate for a stator. We then measured the normal and tangential displacements of the frictional surface of the slider via the transparent stator by means of 2 laser Doppler vibrometers. We thoroughly inspected the measurement conditions and indicated that the measured data were reliable and usable for subsequent precise analyses of the friction drive. The driving conditions for the measurements were a driving frequency of 9.61 MHz and a wave vibration amplitude of 20 nm. The start-up transients of the motor for a duration of 10.4 micros were measured. The measurements showed that the frictional surface of the slider displaced in both the normal and tangential directions followed each wave vibration. The displacements increased with the wave's vibration amplitude: they increased to 10 nm in both directions, in response to the transient increase of the wave's vibration amplitude to 20 nm, under the 15 N preload condition. Moreover, the slider surface rotated in the same direction as the wave surface and its trajectories were a tilted elliptical orbit. Since the surface of the wave rotated in an upright elliptical orbit, the result indicated that the tangential displacement of the slider surface was delayed in relation to that of the wave. The delay was in the range from 30 degrees to 60 degrees under the 15 N preload condition. 相似文献
17.
18.
以电动汽车驱动用永磁同步电机为研究对象,从作用于电机定子表面的电磁力波和电机定子结构的动态特性两个方面对电动汽车驱动用永磁同步电机空载工况的电磁噪声展开研究.通过研究永磁同步电机产生电磁力波的机理,推导了空载工况电磁力波的解析分析方法,结合电磁仿真的手段,精确计算了电机在空载工况下电磁力波的波次、频率和幅值;通过建立电机定子结构的有限元仿真模型及有限元模态仿真计算,得到了定子结构的模态频率和振型.发现:电机定子结构的前6阶模态频率较低,电机空载工况在调速过程中所激发的电磁力容易引起电机定子结构的共振.该研究为电动汽车驱动用永磁同步电机的减振降噪提供了指导. 相似文献
19.
20.
An ultrasonic linear motor using ridge-mode traveling waves 总被引:1,自引:0,他引:1
Tominaga M Kaminaga R Friend JR Nakamura K Ueha S 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2005,52(10):1735-1742
A new type of ultrasonic linear motor is presented using traveling waves excited along a ridge atop a substrate. The ridge cross section was designed to permit only the fundamental mode to be excited during operation of the motor, with a Langevin transducer used as the source of vibration in this study. The ridge waveguide was first made of lossy media to avoid reflecting vibration energy back toward the vibration source, forming a traveling wave. A 5-mm-wide, 15-mm-tall rectangular acrylic ridge was used to move a slider placed upon it toward the vibration source, in opposition to the direction of the traveling wave transmitted along the waveguide ridge. Using a low-loss 3 x 6-mm aluminum rectangular ridge combined with a damper clamped onto the far end of the waveguide, similar results were obtained. To obtain bidirectional operation, the damper was replaced with a second Langevin transducer, giving a pair of transducers located perpendicularly to the ends of the ridge and driven with an appropriate phase difference. The moving direction of the slider was reversed by shifting this phase difference by about 180 degrees. With this simple configuration, it may soon be possible to fabricate a linear micromotor system on a silicon substrate or other semiconductor wafer adjacent to other electronic and optoelectronic devices. 相似文献