Characteristic Analysis And Optimization Of Vibration Performance Of Double Elastic Spindle

Double elastic spindle has the characteristics of high working speed and low vibration,but the domestic research on the dynamic and static characteristics of double elastic spindle is still insufficient.In order to accurately grasp the vibration characteristics of double elastic spindle in the working process,this paper compares and analyzes the influence law of different structural parameters on the performance of double elastic spindle through the three-dimensional modeling simulation and experimental study of the spindle,so as to provide theoretical and experimental research basis for further improving the performance of double elastic spindle.The main research contents and conclusions are as follows:(1)A simplified model of double elastic spindle with different structural parameters was established by using Solidworks software.The Modal module and Modal-Random Vibration module in ANSYS Workbench were used to analyze the diameter of upper bearing stop,lower bearing stop,support distance and the diameter of ingot belt position.And the influence of bearing elements such as inner spindle foot,elastic tube,rolling bearing and plain bearing on the performance of double elastic spindle.The results show that:diameter of the upper bearing position and support distance have obvious influence on the second and third order critical speed and vibration performance of double elastic spindle,because of the change of stiffness.When the diameters of the upper and lower bearing positions are 5.8mm and 3mm respectively,the support distance is 85mm and the spindle belt diameter is 19mm have obvious influence on the critical speed of the double elastic spindle.The elastic tube has obvious influence on the third order critical speed.The inner spindle foot has obvious influence on the first three critical rotational speeds.When the bearing stiffness of upper and lower bearings is the same and increases at the same time,the third order critical speed first remains unchanged while the other five orders increase rapidly,and then the third order critical speed increases rapidly while the other five orders remain unchanged.(2)Gambit software was used to establish a simplified model of double elastic spindle.The fluid-structure coupling analysis was carried out by Fluent and Transient Structural module in ANSYS Workbench,and the influences of eccentricity,speed,radial force,support stiffness on the double elastic spindle are studied.The results showed that:with the increase of eccentricity,the static pressure,dynamic pressure,stress and strain of the double elastic spindle increase,and the fluctuation range of the axis locus increases.When the rotation speed increases from 8000r/min to 20000r/min,the axial locus is stable and the fluctuation is small.The stress and strain increase with the increase of radial force.Eccentricity and supporting stiffness increase at the same time.When the supporting stiffness of the upper and lower bearings is between 1×10~3-1×10~4N/mm,the static pressure,dynamic pressure,stress,strain and axis locus of the double elastic spindle fluctuate less.(3)By comparing and analyzing the amplitude at the critical speed,the amplitude at the critical speed,and the amplitude at the working speed,it is found that the simulation results are 7005r/min,0.20175mm,0.015mm,and the experimental values are:6080r/min,0.2038mm,0.02mm,the simulation value increased by about 15%,-1%,-25%compared with the experimental value,which basically verified the consistency of the simulation and experimental law results.(4)In order to optimize the vibration performance of double elastic spindle,three groups of double elastic spindle and single elastic spindle with different bearing stiffness were prepared.The influence of the plain rod,aluminum rod,yarn clamp and the force generated by spindle belt on the vibration performance of double elastic spindle and single elastic spindle were compared and analyzed through experiments.The results showed that:When the speed is far away from the critical speed,the amplitude of the double elastic spindle of the plain rod and aluminum rod is slightly larger than that of the corresponding single elastic spindle,because the fixed support can suppress the amplitude,but the amplitude of the double elastic spindle with a yarn clamp is smaller than that of the single elastic spindle.The force generated by the spindle belt has no obvious effect on the amplitude away from the critical speed.After adding the surface texture of shark-skin,shell and cybister japonicus with drag-reducing effect,the shark-skin surface texture can reduce the amplitude of the double elastic spindles and single elastic spindles,while the surface texture of shell or cybister japonicus with specific size can reduce the amplitude of the double elastic spindles and make them not affected by the critical speed,so that they can work at any speed.This indicates that the double elastic spindle is suitable for high-speed occasions with yarn clamp,and the surface texture of the shell and the cybister japonicus with specific size improves the performance of the double elastic spindle obviously.