| Chapter 1 Introduction Piezoelectric has a great advantage over other material in precision driving field for its quick and precise response.Comparing with the traditional precision actuator, Piezoelectric has become a new way to fulfill precision actuation recently. The paper summarize the current using field, the types and characteristics of precision driving technology, and sum up the driving materials and status of it. The paper also analyzed the international piezoelectric driving methods and questions existing at present.Chapter 2 The basic theories of piezoelectric driving The piezoelectric drive fundamental principles are piezoelectric effect and converse piezoelectric effect. The factors which influence performance include dielectric constant (,elastic constant S ,piezoelectric constant d ,electromechanically coupled coefficients ,mechanical quality factor ,etc. Piezoelectric material is a kind of elastic solids and its electric characterization can be described by electric field intensity E and electric displacement D. for a dielectric free from external force in electric field, the relation between electric field intensity and electric displacement is: D=εE Piezoelectric driving technology is the extension and development of Piezoelectric in mechanics, which has been successfully applied to: ultrasonic motor, fluid driving and control mechanism, precision driving mechanism.The common piezoelectric actuator has two kinds: piezoelectric stocks and. The paper made with piezoelectric bimorph as drive mechanism and introduced its supporting method, electric-connect method and some common principles of its characteristics.Chapter 3 Moving theories and analyses of theories of the mechanism Make use of the piezoelectric bimorph as driving source, this paper designed three kinds of precision actuator, respectively is the single-DOF actuator to move even, x- y two- DOF actuator to move even and x- y two-DOF actuator to move swing. The paper introduces detailed three kinds of actuators about their material, construction, working principle and processing method.Two kinds of flexible hinge, which is the most important part of the actuator, are involved in this paper, one kind is arc-swing flexible hinge, the other is parallel-move flexible hinge, set out from an actual circumstance for micro-displacement mechanism, and the paper made the theories analysis respectively to two kinds of flexible hinges.Arc-swing flexible hinges, is used in the mechanism of x- y two-DOF actuator to move swing, according to the characteristic of micro-displacement of precision actuator, the theories model is established, and deduce the simplifying method of design; the formula of the angle of flexible hinges is gotten: correspondingly, the formula of rigidity is gotten:In the design of the flexible hinges, the calculation of rigidity is the most important. From analysis we can get: the rigidity of flexible hinges is relative to elastic modulus E of material, the width b of hinges, the radius r of hinges and the minimum thickness t. The elastic modulus of material is fixed after a material has been chosen. Then the width t of the hinges is made certain according to the integer size of the transport part belong to the mechanism, in the end, we should choose the radius of hinges and the minimum thickness.After having anal sized the formula of angle and rigidity, we know that the variety of the minimum thickness of hinges influence the characteristic mostly, whereas the variety of radius of hinges influence the characteristic little. From the formula of rigidity we can know, the relationship between the minimum thickness of hinges and the rigidity is direct ratio, the relationship between the radius of hinges and rigidity is inverse ratio. So, in the design process of transporting part of flexible hinges, the minimum thickness of hinges should be increase as much as we can and decrease the radius of hinges at the same time in order to insure its good...
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