Research On Design Of Tubular Permanent Magnet Linear Motor For Applications Of Reciprocating Gate

Tubular permanent magnet linear motor (PMLM) is a new type permanent magnetlinear motor, it has advantages of both permanent magnet motors and linear motors.Compared with the traditional "rotary motor+ball screw "drive mode the direct-drivemode has advantages such as simplified system structure, high system efficiency, fastresponse, high positioning accuracy and so on. Therefore it has been widely used inapplications such as lifting system (elevator, oil pumping machine), high performanceservo drive (high speed machining center, precision grinder) ect. However there are somedifficulties in actual production and application of this motor due to the changes of itsstructure.So the study on the electromagnetic design method and the working performanceof the tubular permanent magnet linear motors based on its structure characteristics is ofgreat importance.In this thesis a series of problems of tubular permanent magnet linear motors were studiedbased on its structure characteristics. Firstly, the structure and working principle of the tubularpermanent magnet linear motors were analysed, the design method and steps of the tubularpermanent magnet linear motor were given, by using the method ofmagnetic circuit calculationand finite element numerical calculation the size of each part of the motor was determined,andthe rationality of the determined size was verified. Then according to the pie winding structureand the connection mode of the fractional slot winding with the pitch y=1, the magnetomotiveforce distribution of motor winding was analysed in detail based on a single conductor,analytical expressions for the phase winding magnetomotive force was given.. According tothe performence requirements of the tubular permanent magnet linear motor, the method todetermine the output force of this motor was proposed. Secondly, the detent force whichaffects the performance of the tubular permanent magnet linear motors was studied, analyticalexpressions of end force and cogging force were derived respectively and the method to restrictdetent force was gived. The affect of the primary armature core length, primary armature core with auxiliary slots and magnent shifting on the detent force were studied in depth,theeffectiveness of these methods were verified by the finite element simulation.Finally experimentalstudy of the tubular permanent magnet linear motors is taken., and theopen-loop linear reciprocating motion is realised.The discussion in this thesis can provide some guidance and reference for the analysis anddesign of linear motors.