Basic Study Of Clamping Apparatus Using Ultrasonic Levitation

Now, the requirements of products' surface quality become higher and higher in the field of high-precision processing. Such as silicon processing in semiconductor industry, there is a high demand for surface roughness and cleanliness .In order to avoid work pieces scrapping due to minor superficial contamination and scratches during transportation, people have been looking for a non-contact levitation transport way.This article mainly talks about near-field acoustic levitation(NFAL),shows that it is very possible to use ultrasonic levitation in the field of high-precision processing. It aims to analysis principles of NFAL in depth and designs a clamping apparatus which is based on NFAL.In this text, theory about NFAL, finite element method and the direct boundary element method are used to solve some problem, such as Near-field acoustic radiation force, the radiated sound field of ultrasound system, condition of NFAL and the design of clamping apparatus. Main research results are as follows:1. The direct boundary element method used in sound field analysis is studied. Model analysis and Harmonious response analysis of ultrasound system are executed using finite element method, and the radiated sound field of ultrasound system is calculated by using the direct boundary element method. Rectangular horn surface sound pressure and radiated sound field are obtained. The correctness of the proposed method is validated with the academic ones. The result shows that the boundary element method can provide a theoretical basis and reference for the design of ultrasound system which is used for NFAL.2. It establishes a near-field acoustic radiation pressure solving model applying with acoustics theory and derives an initial acoustic levitation calculating formula of rotundity objects. Combining with finite element and boundary element analysis, levitate conditions of levitated objects are calculated. It takes rectangular ultrasonic oscillator for example, testing and analyzing conditions of near-field acoustic levitation by using self-designed test equipments, the results are proved to be better.3. By using finite element methods, the modal analysis and response analysis of harmony of ultrasonic clamp body is designed, getting the changes of amplitude versus frequency of the clamping apparatus system. Finally, the result is verified by experiments.The innovation of the article is as follows:(1) Laser triangulation method is used in measuring the height of NFAL. (2) Finite element method and boundary element method are used together to to obtain Radiated acoustic field on the surface of a rectangular horn;(3) Condition equation of NFAL is obtained;(4) A clamping apparatus which is based on NFAL is designed.