Tham khảo tài liệu 'crc press mechatronics handbook 2002 by laxxuss episode 2 part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | eliminate most errors in bearings supports and guides used in high precision measuring devices. This is due to active bearings and supports possessing several degrees of freedom in which one or both contacting elements are made from piezoactive material with predetermined excitation zones. Radial or axial play backlash and dead zones traditional errors are minimized in these devices. The schematic of active bearing is shown in Fig. a where number of axial n and radial m electrode sectors is n m 3. Active bearings are used in precision component surface and profile measuring systems to scan the surface. The example is outer ring errors evaluation in high precision ball bearings. Here rotating the component simultaneous measurements of profile and surface are obtained. This is possible due to piezoelectric transducers Fig. b contacting with the component in two areas with the same pattern of oscillation distribution and phase shift between normal and tangential components of oscillations. There being no external forces it is evident that errors caused by torque generated in the contact zone are negligible. References 1. Cady W. G. Piezoelectricity Dover Publications New York 1964. 2. Volkov V. Some Theoretical Problems in Modern Techniques of Diagnostics in Mechanical Systems in Proc. Int. AMSE Conf. Systems Analysis Control and Design Lyon France 205. 3. Uchino K. Piezoelectric Actuators and Ultrasonic Motors Kluwer Academic Publishers MA 1997 349. 4. Ragulskis K. Bansevicius R. Barauskas R. Kulvietis G. Vibromotors for Precision Microrobots Hemisphere Publishing Corporation 1988 310. 5. Suzuki Y. Tani K. Sakuhara T. Development of new type piezoelectric micromotor J. Sensors Actuators 83 244 2000. 6. Catalog Ceramic Multilayer Actuator CMA d33 d31 July 2000. 7. Sashida T. Kenjo T. An Introduction to Ultrasonic Motors Oxford Science Publications 1993 Oxford University Press New York 242. 8. Ueha S. Tomikawa Y. Ultrasonic Motors Theory and Application .
