Analysis Of The Normal Force Ripple Of PMLISM On Load And Its Optimal Design

Linear servo motor has the merits of high thrust density, low loss, small electricaltime constant and huge response speed, it can achieve “Direct-driving”in the servosystems of CNC machine tool. The breaking of magnetic, alveolar structure and MMFharmonic bring the ripple of thrust and normal force. Ripple of normal force do not attractsacademic’s attention widely. The normal force ripple will lead feeding table vibration orresonance with other moving components of the servo feeding system, it will affect theperformance of the servo system. For the problem of normal force ripple, this thesis willresearch on the optimal design to deal with this problem.The formulas of flux density of air-gap, thrust and normal force of PMLSM wasdeduced, and the results prove that decent force is the primary aspect that affecting thenormal force ripple. Analyze different MMF harmonic and affect of permeability harmonicto normal force ripple.Reduce the normal force by changing structure of permanent magnet. Basing on theprinciple of constant thrust and minimum normal force, simulate the improved programwith Ansoft, contrast the normal force and trust with different sizes by curve fitting, obtainbest size value causing smallest normal force ripple with Limited Enumeration Method.Reduce normal force with auxiliary slots in tooth portions mover. By auxiliary slots intooth portions mover of PMLSM, achieve the goal of reducing normal force afterestablishing sizes and amounts of auxiliary slots.Research a measurement method of PMLSM, obtain normal force fluctuation valuethrough experiment. Contrast the measured value and simulated value.The normal force analysis method and optical method in this article possess certainadvising significance and practical value and contributes develop of country’shigh-precision NC technology.