Reliability Analysis Of Key Components Of Permanent Magnet Synchronous Electric Spindle

With the developing of industrialization in China,the requirements to precision and the life span of mechanical equipment are higher.Due to the advantages of compact structure,low vibration,low noise and good stability,the Permanent Magnet Synchronous Electric Spindle(PMSES)is widely used in CNC machine tools,machining centers and other mechanical equipment.The reliable operation of PMSES plays an important role in increasing the processing efficiency,improving the quality of the workpiece and safety production.So,it is necessary to analyze the fatigue life and reliability of the key components of the PMSES.In the traditional design of the PMSES,the parameters of the key components,such as the size,the material property,the load and so on are usually set as fixed values without considering their varieties.In addition,traditional methods often improve the reliability of the PMSES by increasing its size,which not only increases the volume and the cost,but also can not ensure the reliable operation of all the PMSES.In this dissertation,the finite element method is used to study the fatigue life and reliability of the key components of PMSES.The main work of this dissertation includes the following aspects.The stress of the key components of the PMSES is solved.Based on the analysis and calculation of the air gap magnetic field,the output torque and radial electromagnetic force density with time and position are extracted.The frequency spectra are analyzed.Based on the mechanism of unbalanced magnetic pull,the unbalanced magnetic pulls of the PMSES at concentric and eccentric are calculated respectively.The modal analysis,static force analysis and harmonic respond analysis of the key components of the PMSES are carried out by using ANSYS Workbench software.Through the modal analysis,the natural frequency and vibration mode of the key components are obtained.It is verified that the natural frequency and the excitation frequency will not coincide when the PMSES is running normally.This structure can effectively avoid resonance.By means of static force analysis and harmonic respond analysis,the stress distribution nephogram of the key components is obtained,and the maximum stress of the component is lower than the yield strength of the material.The result of static force analysis and harmonic respond analysis are transferred to nCode DesignLife software.The fatigue life of the key components is determined by nCode Design Life software.The Six Sigma module in ANSYS Workbench software is used to analyze the reliability of key components by considering the size,material and load of key components.The analysis results intuitively show that the impact of each input variable on the output variables,namely,the influence of input variables to the sensitivity and the reliability of the key components of the output variables.According to the analysis results,the structure is improved.In this dissertation,the life span of the key components is determined,and the main parameters affecting the reliability are analyzed by the fatigue life analysis and reliability analysis of the key components of the PMSES.The analysis results provide an important reference for the improvement of the key components of the PMSES,which is of great practical significance.