共查询到19条相似文献,搜索用时 140 毫秒
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根据几何参数和简化原则建立电主轴实体模型。采用滚动轴承拟静力学模型准确计算轴承刚度,建立主轴-轴承系统有限元模型,设计模态测试实验较好地验证了仿真结果。基于主轴有限元模型,以主轴转子外圆直径、内孔直径、悬伸量、支承跨距以及轴承配置形式为设计变量;以主轴转子一阶固有频率最大和质量最轻为优化目标;以主轴转子前端静变形、最大应力、主轴各段尺寸均在限定范围内为约束条件,对电主轴转子进行优化设计。将提出的优化方法应用于某磨齿机电主轴,优化后主轴一阶固有频率提高33%,质量减轻21%,实现了电主轴高刚性和轻质量优化目标,为电主轴数字化设计提供技术支持。 相似文献
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介绍了紧凑型高速电主轴的结构设计,建立了主轴-拉刀机构双转子系统模型,研究了电主轴拉刀机构的静动态特性,得到了工作状态下电主轴的静态位移、振型、固有频率以及关键点的响应位移。对主轴-拉刀材料、轴承预紧力、轴承组跨距、主轴-拉刀接触刚度以及主轴-刀柄接触刚度等参数进行优化设计。结果表明优化后电主轴的静动刚度均满足要求、固有频率提高、电主轴安全工作频率区间增大。电主轴模态测试结果证明了以上结果的可靠性。该研究为紧凑型高速电主轴的设计提供了理论基础。 相似文献
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基于有限元方法的电主轴支承跨距优化设计 总被引:1,自引:0,他引:1
通过对某铣削用电主轴的支承特点进行分析,建立了其轴承-主轴系统的参数化有限元模型,应用有限元分析软件ANSYS的优化设计功能,以提高电主轴的刚度为目标,取前后轴承的支撑跨距为设计参数,第一阶自振频率为校核条件,对该型电主轴进行了优化设计.结果表明,优化结果虽然使主轴的一阶自振频率略有降低,但却使主轴的刚度有了较大幅度的提高. 相似文献
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通过对某铣削用电主轴的支承特点进行分析,建立了其轴承一主轴系统的参数化有限元模型,应用有限元分析软件ANSYS的优化设计功能,以提高电主轴的刚度为目标,取前后轴承的支撑跨距为设计参数,第一阶自振频率为校核条件,对该型电主轴进行了优化设计。结果表明,优化结果虽然使主轴的一阶自振频率略有降低,但却使主轴的刚度有了较大幅度的提高。 相似文献
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《机械制造与自动化》2016,(2):50-53
以某大功率高速铣削加工中心电主轴系统为研究对象,采用有限元法,综合考虑高速状态下主轴系统阻尼比、陀螺力矩效应和轴承刚度软化3种因素,建立了高速电主轴系统的动力学方程。得到了主轴系统由转速引起的陀螺力矩效应,轴承刚度变化两种因素影响下的前6阶固有频率,并进一步得到了上述3种因素影响下的刀尖处频率响应。结果表明在高速状态下,轴承刚度的软化对固有频率的影响大于陀螺力矩效应;而主轴系统的结构阻尼比会减弱轴承刚度软化对刀尖处频率响应的影响。 相似文献
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文章通过NewSpilad软件对电主轴进行静态和模态分析,探究轴承预紧力和主轴悬伸量对主轴刚度及固有频率影响。结果表明:调整轴承的预紧力对主轴径向刚度影响很小,变化量在20%以下;轴向刚度影响较大,变化量在50%以上;对主轴的固有频率影响较小,最大变化量为24%;增加悬伸量对主轴轴向刚度影响较小,变化量在5%以下;对径向刚度影响较大,变化量在13%左右;一阶固有频率有提升趋势。并通过主轴静动态特性测试试验验证,对比发现有限元分析结果与实际测试结果误差在10%以下。该研究结果为主轴静动态特性分析提供理论基础,进一步提升了主轴设计开发能力。 相似文献
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高速磨削用电主轴结构动态优选设计 总被引:5,自引:0,他引:5
考虑滚动轴承径向刚度随转速非线性变化,运用传递矩阵法对电主轴的临界转速和静刚度特性进行了系统的研究,用Matlab工具开发了一套具有自主知识产权的动态计算分析软件。以某款精密高速(51000r/min)磨削用电主轴为对象,分析了主轴结构参数与砂轮参数对主轴动态特性的影响,并对主轴结构进行了优选设计。结果表明,基于传递矩阵法编制的电主轴动态设计软件运行可靠、操作简便,可应用于电主轴的动态设计与快速开发。经优选设计后,电主轴的一阶临界转速和主轴端静刚度均有较大幅度的提高。 相似文献
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基于ANSYS的电主轴转子-轴承系统动静态性能分析 总被引:1,自引:0,他引:1
《机械设计与制造》2015,(9)
在电主轴的结构设计中,影响轴承转子系统的动静态特性的主要因素就是轴承位置的选择。通过应用有限元分析软件ANSYS,对洛轴某型号的磨削电主轴的转子—轴承系统进行二维和三维参数化建模并进行动静态特性分析,以主轴的静刚度和前4阶固有频率为目标参数,通过改变不同的轴承位置和内径的大小,得出了前后轴肩的距离以及孔径同目标参数之间的关系曲线,定量定性地分析了前后轴承的位置以及孔径对电主轴的动静态特性的影响,为以后小型电主轴的内部结构设计尤其是轴承位置设计提供了有力的依据。 相似文献
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制造装备主轴优化设计及其软件研制 总被引:2,自引:0,他引:2
给出制造装备主轴优化设计及其软件的设计思想。该软件供车床、铣床等制造装备主轴部件的一组结构参数作优化设计,软件的功能广,可为两支承或三支承的主轴部件设计,又可把主轴支承变形量计入或不计入主轴刚度计算中,主轴的工作状况、支承类型及结构条件都可由制造装备性能的需要作实时选择。用软件包设计,使主轴部件具有最佳刚度,它与人工设计方法相比,不仅设计质量高,而且可提高设计效率达百倍以上,经实例验证并取得了很好的效果。 相似文献
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基于对具有硬质车削功能的高刚度数控车床的主轴相应的高精度、高刚度要求,在对主轴分析研究的基础上,采用弹簧阻尼单元模拟轴承支承,建立主轴的有限元模型,进行静、动态特性分析,并对固有频率随轴承支承刚度的变化关系进行了模拟研究。计算结果表明,采用该方法分析高刚度数控车床主轴单元可以得到满意的结果,为工程设计提供了一定的参考。 相似文献
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For ultra-precision machining machine tool components need to operate outside critical frequencies of the machining system to avoid insufficient surface finish caused by vibrations. This particularly applies to tooling spindles as those are generally the component of a machine tool with low stiffness and damping values. Surface finish and shape of a machined part rely directly on the overall accuracy in motion of the tooling spindle over the entire machining parameter and speed range. Thus spindle designs for an operation outside critical frequencies combined with high stiffness and damping values are crucial for ultra-precision machining.For sufficient stiffness properties bearing gaps of gas bearings have to have a size of only a few microns and show a distinct sensitivity on temperature and for journal bearings also on speed. This again means that bearing properties change with temperature and speed. Considering a spindle system comprising a rigid shaft rotating in a radial/axial bearing system with changing stiffness and damping properties leads to a resonance speed map with changing rigid mode resonance speeds.This paper treats the influence of shaft speed and temperature on bearing gaps from which rigid mode resonance speeds for a shaft spinning in a bearing system are derived. The quoted influence of centrifugal load and temperature on bearing stiffness, damping and load capacity can be applied to any kind of gas bearing. Therefore the calculation of bearing stiffness, damping or load capacity is not treated in detail. The reader will be shown that there are simple design rules for air bearing systems and shafts of high-speed tooling spindles to avoid critical speeds through the entire speed range. Finally, methods of how to prove the initial design goals and how to verify dynamics of high-speed spindles in production will be presented to the reader. It will also be shown that there are production high-speed spindles available which do not include any critical speed within their speed range and thus show robust rotor dynamics with extremely low errors in motion.Procedures in design, validation and application treated in this paper shall give the reader not only design guidelines for spindles to avoid critical spindle speeds within its speed range, but also recommendations for machine tool builders and end-users for a machine operation taking machine and rotor dynamics into account. As the knowledge for this paper is predominantly based on the experience and work of the author himself only a few references are used. However presented testing results entirely confirm the approach presented in this paper. 相似文献
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M. A. Mannan Professor B. J. Stone 《The International Journal of Advanced Manufacturing Technology》1998,14(12):889-893
The assembly of machine tool spindles results in a degree of variability in the effective stiffness of the bearings. This may result in a poor machining performance if the bearing stiffnesses are below their specified design values. Alternatively, the life of the bearings may be reduced if the bearings stiffnesses are above the design values because of excessive preload. This paper describes a method of checking the spindle assembly by making vibration measurements. From these measurements it is possible to determine which bearings (if any) are not at their design stiffness. This then allows appropriate adjustments to be made to ensure the assembled spindle is close to the design specifications. 相似文献
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A key component of ultra-precision machine tools is the spindle. The motivation for this study was to improve machining accuracies in precision cutting and grinding by pursuing improvements in the spindle characteristics by designing a sophisticated spindle with water-lubricated hydrostatic bearings. The static bearing stiffness of the developed spindle was investigated in previous studies. In addition to the static bearing stiffness, the dynamic characteristics regarding bearing stiffness also affect significantly on the machining results. In this study, dynamic characteristics of the developed spindle with water-lubricated hydrostatic bearings were investigated via simulations and experiments. Not only bearing dynamics but also rotor dynamics were considered in this study.In the simulation studies, the spindle dynamic characteristics were analysed based on the transfer matrix method. A spindle rotor supported with hydrostatic bearings was represented by discrete sections of the rotor. The mathematical model of transverse linear vibrations of the spindle rotor was derived with distributed parameters for these discretized rotor sections. As a result of the analysis on the amplitude-frequency characteristic, radial displacements of the rotor due to bearing displacement and bending deformation were defined. Then, the frequency characteristics were represented with Nyquist plots. Resonant frequencies and amplitudes formation in the transverse vibration of the rotor were determined. The influence of rotor bending deformations on spindle compliance was assessed. Furthermore, the study examined the influences of the supply pressure of the lubricating fluid, radial clearance and journal diameter of the hydrostatic bearings on the amplitude of the rotor vibration, and the resonance frequency of the system.Furthermore, the dynamic characteristics of the spindle were examined experimentally. The simulation results were in good agreement with the actual spindle dynamics obtained experimentally. The influence of the structural parameters of the rotor and the operating parameters of the bearings on the spindle dynamic characteristics was also determined. It was verified that the amplitude of the vibration of the rotor overhang part was dominantly affected not by bearing stiffness but by bending stiffness of the bearing journal of the front bearing and the length of the rotor overhang.Then it was verified that the resultant displacement of the rotor in the radial direction due to the influence of the bearing characteristics and the structural effect of the rotor is significantly small. Practical recommendations to improve the spindle design in terms of the dynamic characteristics of the spindle with water-lubricated hydrostatic bearings were also derived. 相似文献
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超精密空气静压主轴静态性能的数值分析 总被引:1,自引:0,他引:1
为了对超精密空气静压主轴静态性能进行数值分析,利用有限元法求解空气静压轴承内的压力分布,计算径向和止推轴承的承载、刚度和供气流量。研究轴承参数对轴承静态性能的影响,提出空气静压轴承的设计准则。推导出精密主轴承载、径向刚度、轴向刚度和角刚度的计算公式。实验证明数值分析是正确的。 相似文献