Research On Transmission Characteristics Of Permanent Magnet Eddy Current Speed Governor

Permanent magnet eddy current speed governor is a kind of mechanical transmission system that uses induction eddy current to transmit power and adjust speed.It has the characteristics of soft start,vibration isolation,no need for accurate calibration,high reliability,energy saving and so on.Therefore,it has great application prospect in fan,pump and other industrial fields.The research and optimization of the transmission characteristics of speed governor are the basis of its design and development.Therefore,the study of the influence of different factors on its transmission characteristics and structural optimization are beneficial to the rapid design and development of speed governor products and the reduction of costs,so it has important theoretical significance and practical value.Aimed at the research and optimization of the transmission characteristics and its influencing factors of permanent magnetic eddy current speed governor,this paper analyzed the working principle of speed governor,and established the optimized mathematical model of the transmission characteristics by considering the magnetic leakage factor,thus summarizing its main influencing factors.Based on the three-dimensional finite element transient field analysis method,this paper studied the effects of different factors on the transmission characteristics,and proposed the program about the design of speed governor and the optimization of transmission characteristics.Besides,by designing and building the experimental system,this paper completed the experimental analysis and the verification of the transmission characteristics.The main research work of this paper are as follows:(1)Deeply analyzed the research status of the transmission characteristics of permanent magnet eddy current speed governor at home and abroad and pointed out its development trend.Based on the equivalent magnetic circuit method and the electromagnetic theory,an optimized mathematical model of the transmission characteristics was established by considering the impact of the magnetic leakage factor,thus summarizing its influencing factors.Moreover,the relationship between transmission torque and slip,air gap size and other factors was given from the theoretical point of view.(2)Based on the ANSYS Maxwell electromagnetic field analysis software and the three-dimensional finite element transient field analysis method,studied the effects of factors such as thickness of copper plate,inside and outside diameter of copper plate,material of copper plate back plate,thickness of permanent magnet,circumferential distribution of permanent magnet,cross-sectional shape of permanent magnet and material of permanent magnet plate back plate on the transmission characteristics.Besides,proposed the program about the design of speed governor and the optimization of transmission characteristics.Finally,by analyzing the circumferential distribution of the magnetic induction intensity of the air gap magnetic field,verified the effect of the magnetic leakage on the transmission characteristics from the perspective of the magnetic induction intensity of the air gap magnetic field.(3)Designed and established the experiment system with adjustable load,torque and speed feedback and other functions for the analysis of the transmission characteristics of permanent magnet eddy current speed governor.Completed the design,processing and assembly of the main components of the platform;proposed the design of monitoring system,and completed the selection and layout of functional modules and the development of software functions.(4)Carried out the experimental analysis of the influence of the size of the air gap,the thickness of the copper plate,the material of the copper plate back plate and other factors on the transmission characteristics.Verified the rationality of the result of theoretical analysis and three-dimensional finite element transient field analysis about the transmission characteristics.Moreover,verified the rationality of the program about the design of speed governor and the optimization of transmission characteristics.