Study On Working Characteristics Of Permanent Magnet Couplings

Generally speaking, permanent magnet couplings are composed of insidemagnet rotor, outside magnet rotor and isolative sleeve. The inside magnet rotor isconnected with follower,while the outside magnet rotor is connected with driver.On one hand, permanent magnet couplings have the function of cushion andabsorption of shock as well as flexible coupling,on the other hand, the most majorcharacteristic of permanent magnet couplings is that inside magnet rotor andisolative sleeve are isolated from others completely,besides this,under the conditionof no mechanical contact,the driver transfers motion and dynamic force to thefollower by means of magnetic force,in consequence,dynamic seal of permanentmagnet couplings becomes static seal. Therefore, permanent magnet couplings areapplied widely to the fields which have especial requirement of seal,such as fieldsof petroleum,chemical engineering, vacuum, low temperature, pharmacy, food,aviation and so on. According to the arrangement of magnet rotors, permanentmagnet couplings include sleeve type and disk type. In this article, the workingcharacteristics of sleeve-type Permanent Magnet Couplings which have eightmagnetic poles are studied. This article consists of six parts shown as followed:1) Introduction This part introduces classification and working mechanics of permanentmagnet couplings simplely and research contents of this article.2) The analysis of air gap magnetic field of the permanent magnet couplings In this part, mathematics model of air gap magnetic field of the permanentmagnet couplings based on the theory of equivalent magnetic monopoles isestablished,and influences of main structural parameters on air gap magnetic fieldare analyzed.3) The analysis of magnetic torque of the permanent magnetcouplingsIn this part, mathematics model of magnetic torque of the permanent magnetcouplings based on the theory of equivalent magnetic monopoles is established,andinfluences of main structural parameters on magnetic torque are analyzed.4) The analysis of eddy current loss in isolative sleeve,andmagnetic torque arose by eddy currentFirst of all, mathematics model of the eddy loss in isolative sleeve based onMaxwell equations and the mathematics model of air gap magnetic field isestablished,and influences of the relative rotation angle between magneticrotors,the rotational speed of magnetic rotors and the thickness of isolative sleeveon eddy current loss in isolative sleeve are analyzed. Then,the mathematics modelof magnetic torque arose by eddy current is established,and influences of therelative rotation angle between magnetic rotors,the rotational speed of magneticrotors and the thickness of isolative sleeve on magnetic torque arose by eddycurrent is analyzed.5) Module for analysis of magnetic field of the permanent magnetcouplings based on ANSYSFirstly,this part introduces user interface design language(UIDL) for graphicaluser interface(GUI) in ANSYS,and establishes module for analysis of magneticfield of the permanent magnet couplings with eight magnetic poles. In the end,thefinite element result obtained from an example is compared with the analyticalresult obtained from the mathematics model of air gap magnetic field of thepermanent magnet couplings.6) Conclusions and prospectsIn this part,conclusions of this article and prospects of the study in the futureare given.