Research On Rotated Actuator Driven By Piezoelectric Inertial Asymmetrical Structure

The rotated actuator which was driven by piezoelectric inertial concussion are developed in this thesis, with the support of the National Natural Science Foundation of China science fund program"The Theory and Experimental Study of New Style Micro Inertial Actuator Driven by Piezoelectric Travel Mechanism". Using piezoelectric multilayered actuator (PMA) to replace traditional piezoelectric stack as the drive element, using its characteristics of high power destiny, large output force, fast response and high resolution; getting the forward backward driving moment difference through inputting symmetry signal,using square-wave electrical signal to realize inertial impact force and make the actuator revolve. Simultaneously design and manufacture two kinds of driving actuator prototype,and make the experiment test of the two kinds of mechanism.The paper consists of six chapters, given as follows:1.IntroductionFirst conduct the precision driving technology of the current main application field and the types,make a summary on piezoelectric materials of the current situation, piezoelectric inertial driving has many characteristics such as compact configuration, good response. convenient control and non-electromagnetism interference, the piezoelectric inertial actuators are widely applied in various fields such as product assembly precision component micro manufacture and superficial atomic level survey. Piezoelectric actuators are devided into three kinds. The inertial drive actuator plays an important role in this field as a result of its particular characteristic,due to the high cost and the current inertia driver general using the piezoelectricity to fold generally piles the achievement to actuate the part not easily to connect the big quality block because of the structure limit.So the paper present a new style inertial actuator driven by piezoelectric bimorph, uses its dynamic characteristic making the actuator revolve by a special way.2.The basic theory of piezoelectric driveThe piezoelectric actuation principle and the correlative basic theory is the theoretical start of analyzing piezoelectric multilayered actuator. Piezoelectric ceramic is one of piezoelectric material which in common use. The factors influence performance include dielectric constantε,elastic constant s,piezoelectric constant d,electromechanically coupled coefficients K,mechanical quality factor Qm, etc. emphasizing to analyse the PZT material coefficient of dielectrical loss matrix, the elastic constant matrix and the electric constant matrix notation.As one of the species piezoelectronic effect of effect elastomer, There are four corresponding groups of equations to the different boundary conditions.The paper introduces respectively the performance the piezoelectric stack and piezoelectric bimorph. Piezoelectric bimorph has the advantages of large distortion,easy to link other object,low cost etc. Piezoelectric bimorph adopt the LE mode of piezoelectric oscillator which is the main mode when the piezoelectric oscillator is bending.The piezoelectric cantilever suits for producing the inertial impact force. These basic theories are the foundation of structural design and performance analyse of the inertial actuator.3.The analysis of piezoelectric bimorph vibratorAs the driving element of the actuator,the performance of the piezoelectric cantilever is very important to the movement performance of the actuator.Through the way of theory research and testing,analysed the relationship between the parameters of the bimorph and the displacement in the end of the piezoelectric cantilever and the stiffnessthrough its finite element analysis,make a conclusion of static and dynamic characters: its deformed value of free end reduces when the thickness of base plate and piezoelectric wafer increases, the length of piezoelectric wafer reduces, and the influence of valid base plate's length and piezoelectric wafer's width is small. The first-order free frequency of piezoelectric bimorph vibrator is as the same. On this basis, has initially designated the piezoelectricity twin lamellae oscillator structure size parameter. The principle to selecting parameters of piezoelectric bimorph vibrator is ascertained finally, through its finite element analysis, static and dynamic test.4.The principle of rotated actuator driven by piezoelectric bimorphOn the basis of new piezoelectric inertial drive principle in the case of directional motion, according to the difference of forward backward inertial driving force using piezoelectric bimorph vibrator. Analyze the motion dynamic performance, ascertain actuator's four motion state through calculating Mq1, Mq2 and Mf, and the conclusion is: make Mq2≤Mf