Design And Research On Key Technology Of Linear Motot Used In Machine Tools

With the progress of science and technology, mechanical feed system toward thedirection of the high-precision, high-efficiency and green development. Machine tool feedsystem put forward higher requirements for ultra-high-speed cutting, ultra-precisionmachining, has been unable to meet the requirements of the traditional rotary motor ballscrew structure. Therefore, the permanent magnet linear synchronous motor (PMLSM)direct drive technology has been widely applied in the field of precision positioning. Thispaper focuses on the key technology of machine tools with a permanent magnet linearmotor to start the work done mainly includes the following sections:First, according to the the machine linear motor design requirements andcharacteristics, summed up the characteristics of permanent magnet motor and linear motorand made electromagnetic design. The principle of combining design process usingfractional slot permeance modulation suppression cogging force, selected several windingstructure were analyzed. The analysis of the performance of the motor from the structuralparameters.Secondly, the design of the motor, in order to improve the thrust density of the motor,the motor has a high electrical load calculation software analysis of the temperature riseand the temperature distribution of the temperature field and thermal circuit. Parametersthrough the adjustment of winding turns, the design of the winding parameters to obtain asuitable back-EMF parameters (back EMF generated by the unit line speed) to maximizethe back-EMF constant motor reaches a maximum operating speed indicators premise, inorder to improve the unit currentthe thrust generated by the motor, thereby furtherimproving thrust density.Finally, the force of the end for the permanent magnet linear motor end effect, mademinimize design analysis. Starting from the wave theory of the permeability, to optimizethe primary length of the method to change the phase of the wave of the magneticpermeability of the both ends of the permanent magnet linear motor, so as to weaken the force of the end portion. Analysis comparing different primary length when the end of theforce’s size to select the optimal primary length. For PMLSM the end edges teethchamfered processing, so that the ends of the magnetic field distribution of the linearmotors on both sides evenly so as to achieve the purpose of the weakened end force. Theend portion formed in the phase shifting process using two unit motor the four endspermeability phase mediation more effective to weaken the force of the end portion. By thewidth of the material of the magnetic isolation in the motor between the two units of thecontrast comparison, the optimal width of the separated magnetic material to further reducethe force of the end portion.