Study On Four-foot Differential Motion Stepping Linear Piezoelectric Motor

Micro-nano precision driving and positioning technology is one of the main supporting technologies in the field of ultra-precision processing,precision measurement,precision optics,modern medical technology,biotechnology,aerospace and other fields.As a new technology,piezoelectric precision driving technology has attracted extensive attention and it has been researched by experts and scholars both from home and abroad for its precision advantage and unique stable output capability.It is gradually replacing other precision driving.Laminated piezoelectric ceramic is an important actuating element in the piezoelectric precision driving technology,which plays an important role in the realization of non-resonant driving.In order to get high-precision and large-stroke linear drive,this paper presented the operating principle of using four sets of laminated piezoelectric ceramics to realize step-by-step linear motion with differential action.Laminated piezoelectric ceramics could meet the requirements of high precision,and the differential action mode could meet the requirements of the large stroke.In this paper,the research background,purpose,significance,production and characteristics of piezoelectric actuators were summarized.The research progresses of different piezoelectric actuators were summarized.The advantages and disadvantages of different piezoelectric actuators were analyzed.The current piezoelectric precision drive problems were compared.The application of piezoelectric actuators in production was listed.The materials,structure and basic characteristics of the laminated piezoelectric ceramics were introduced.The relevant properties were explored through experiments.The mechanism of differential action and the mechanical model were theoretically analyzed.The whole structure of differential linear motor was designed.The design of driving foot and pretension mechanism were described in detail.The application of flexible adapter was described.The four-foot driving signal with differential action was designed and the motion state of four feet and slide plate in one cycle were simulated.The motor prototype was assembled.The experimental platform was set up and confirmatory experiment and output experiment were completed.The experimental results of prototype verified the principle of differential actuation which could realize stepping drive.The working voltage of the prototype ranged from 30 V to 100 V,and the driving step and speed increased with the increase of voltage in this range.The working frequency of the prototype ranged from 1Hz to120 Hz and the driving step and speed increased first and then decreased with the increase of frequency in this range.Under the voltage of 100 V and the frequency of 100 Hz,the speed of the prototype was the fastest 960?m/s.When the voltage was 120 V and the frequency was 1Hz,the step of the prototype was the minimum 0.26?m.Under the voltage of 100 V and the frequency of 100 Hz excitation,the maximum horizontal bearing capacity was 25 N.Other contact pairs have been attempted and the experimental results showed that neither the rubber ball nor the plastic ball has the expected experimental results.Both the silicon nitride ball and the aluminum oxide ball could achieve the expected results.The comparative experiments showed that the output characteristics of the alumina ball better than the silicon nitride ball.