共查询到20条相似文献,搜索用时 15 毫秒
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The spindle bearing system is the main source of the total cutting point compliance of machine tool structures. In this work, the static and dynamic characteristics of a spindle bearing system driven by a gear located on the bearing span were investigated using the analytical and finite element methods. Based on the calculated results, a prototype spindle bearing system was manufactured and its static and dynamic characteristics were measured. From the comparison of the experimental results with the calculated results, it was found that the finite element method predicted well the static and dynamic characteristics of the spindle bearing system. 相似文献
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数控机床主轴系统是数控机床的关键子系统,其故障较多,而每次故障现象又比较单一,因此,单纯通过故障现象往往不能作为故障诊断和排除的依据。应用 FMECA 分析方法,分析数控机床主轴系统各组成部分的故障模式及故障原因,并进一步计算各组成部分的危害程度,得到的危害程度为制定设备维修策略提供了参考。 相似文献
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Tae Jo Ko Tae-weon Gim Jae-yong Ha 《International Journal of Machine Tools and Manufacture》2003,43(1):411
Thermally induced errors reduce the accuracy in precision machining, and a great deal of research has been presented on compensation for these errors in machine tools. However, during the transition period after commencing or stopping spindle rotation, thermal deformation behavior is very complex. In particular, the y-directional movement of the vertical machining center cannot be explained by thermal expansion alone because of the relationship between deformation and temperature. Thermal bending that is generated from the thermal gradient in the structure causes this movement. In the research described in this paper, a theoretical explanation and an experimental verification is given for the particular behavior of spindle thermal deformation. As it is not easy to map the relationship of the compensation model, separation of the steady from the non-steady state in the mapping process is strongly recommended. 相似文献
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Sun-Min Kim Kang-Jae Lee Sun-Kyu Lee 《International Journal of Machine Tools and Manufacture》2002,42(3)
This paper investigates the effect of bearing assembly tolerance on the spindle–bearing compliance. In a high-speed spindle system, the bearing characteristics are significantly influenced by the initial assembly tolerance and the thermal deformation of the bearing support structure. In particular, in the very early stage of spindle operation, spindle–bearings could be under hazardous conditions due to the rapid change of the internal pressure resulting from the thermal deformation or the centrifugal force-oriented deformation. The bearing's internal clearance may be also changed with the operating conditions such as external load, rotational speed and operating cycle time. To determine the initial tolerance and the optimal cooling regimen, a comprehensive dynamic modeling and analysis of the high speed spindle system in terms of bearing pressure, bearing compliance and heat generation is required with consideration to those effects. Furthermore, in order to predict spindle characteristics in operation, all of these parameters should be monitored and recalculated in real time. For this purpose, simple and effective equations have been suggested, representing the bearing stiffness in accordance with the thermal deformation. Moreover, contrast to the former bearing analyses which are mostly based on the Hertzian contact model without considering the radial elastic deformation of the races, this paper presents the analytical and experimental investigations on the bearing compliance with additional consideration to both the elastic deformation of the race and the thermal deformation of the housing in terms of the bearing stiffness. The experimental results show the effectiveness of the proposed equations, which will provide a very simplified calculation of the bearing stiffness in dynamic simulation. 相似文献
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以降低主轴产端动柔度值为优化目标,综合利用传递矩阵法和子结构的概念,寻找薄弱模态和计算共能量分布率,并编制了相应的计算机程序,使调参能方便地在微机上进行。 相似文献
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滚动轴承是机器中广泛应用的零件之一,依靠滚动体和滚道间的滚动接触来支承转动零件,轴承的使用寿命是轴承质量的重要衡量指标。针对滚动轴承失效形式主要是疲劳点蚀,往往采用接触疲劳寿命来反映轴承寿命,它综合考虑了轴承材料、接触特性等因素,更符合实际工况。采用MATLAB GUI软件平台完成角接触球轴承接触疲劳寿命计算系统设计,该系统使用方便,只需输入相关参数,便可计算出接触疲劳寿命、最大接触载荷和最大接触应力等参数,结果可在系统界面显示或输出txt文件和excel表格。该系统大大缩短了轴承寿命计算周期,提高轴承设计效率和精度。通过多次工程设计验证,该系统高效可靠,为工程设计中其他复杂计算系统的开发提供了参考。 相似文献
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针对数控蜗杆砂轮磨齿机磨削过程中具有简谐振动的特点,建立其主轴系统的三维有限元模型。利用有限元分析软件ANSYS进行模态分析和谐响应分析。通过模态分析求解获得了主轴系统的固有频率和振型,并研究了角接触球轴承支承刚度对其固有频率的影响;通过谐响应分析获得了主轴系统的变形—频率响应曲线,最后通过计算临界转速来验证主轴系统是否发生共振。研究结果表明:增大角接触球轴承的支承刚度有利于提高主轴系统的固有频率。磨削激振力的频率在600Hz附近时,变形—频率响应曲线出现了最大的峰值响应为6.56μm。为了避免共振,主轴系统的工作转速应尽量避开一阶临界转速。 相似文献
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某数控机床主轴轴承运行613 h后出现振动异常,发现失效轴承个别钢球表面存在明显损伤痕迹,通过宏微观观察,化学成分分析,能谱分析等方法对钢球表面的损伤痕迹进行研究。结果表明,由于金属异物颗粒进入轴承,异物与钢球发生粘着磨损,随着粘着磨损作用加剧,在钢球表面产生“白层”,“白层”内部萌生接触疲劳裂纹,疲劳裂纹扩展使钢球表面剥落,形成剥落坑,引起轴承失效。失效轴承的各部件硬度差值超出标准,加速了轴承的失效。因此建议对轴承添加防尘盖或密封圈,提高润滑油脂的洁净度,避免外界异物污染轴承引起失效,并在实际生产中加强轴承材料的质量控制。 相似文献
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A study on the development of a multi-purpose spindle system for quality productive machining 总被引:2,自引:0,他引:2
A compact multi-purpose spindle for multi-tasking machine tools has been developed such that it can provide high power and torque for lower speed ranges while it rotates at high speeds for light duty machining. The innovative design based on the dual direct drive concept has been adopted such that the size of the spindle can stay the same as a conventional spindle of its class. For optimizing the design process, a method based on the complete virtual approach using 3D solid models has been studied and developed. Machining performance has been verified through a physical prototype. 相似文献
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吴隆 《组合机床与自动化加工技术》2004,(5):111-112
文章介绍了用于高速切削加工的磁力轴承主轴的结构、刚度曲线及其耐磨损、低功耗、高精度、高速度等主要特性,并通过与传统的各类轴承主轴的比较,揭示出磁力轴承主轴的优良特性及其广阔的使用前景. 相似文献
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以TH6350卧式加工中心为研究对象,构建了一套基于虚拟仪器系统的加工中心主轴系统温度场和热误差测量系统,测出了加工中心主轴系统的温度场和各项热变形.建立了基于I-DEAS的加工中心主轴系统的温度场和热变形有限元模型,得到了主轴系统的温度场和热变形分布及其计算结果,计算结果与实测值得到了较好的吻合,研究结果为加工中心的改进设计、温度控制和误差补偿提供了理论依据. 相似文献
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Cheng-Hsien Wu Yu-Tai Kung 《International Journal of Machine Tools and Manufacture》2003,43(15):1521-1528
A high-speed drive system generates more heat through friction at contact areas, such as the ballscrew and the nut, thereby causing thermal expansion which adversely affects machining accuracy. Therefore, the thermal deformation of a ballscrew is one of the most important objects to consider for high-accuracy and high-speed machine tools. The objective of this work was to analyze the temperature increase and the thermal deformation of a ballscrew feed drive system. The temperature increase was measured using thermocouples, while a laser interferometer and a capacitance probe were applied to measure the thermal error of the ballscrew. Finite element method was used to analyze the thermal behavior of a ballscrew. The measured data were compared with numerical simulation results. Inverse analysis was applied to estimate the strength of the heat source from the measured temperature profile. The generated heat sources for different feed rates were investigated. 相似文献
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联合外载荷作用下角接触球轴承内部载荷分布和变形的数值迭代计算 总被引:2,自引:0,他引:2
为了研究联合外载荷作用下球轴承的内部载荷分布和变形特性,提出一种基于赫兹接触理论的数值迭代计算方法.以角接触球轴承为对象,考虑在预紧力、轴向力、径向力等联合外载荷工况条件下内外圈滚道接触角的变化,以及滚珠载荷分布、载荷大小随接触角的变化,利用滚道接触角与滚珠载荷之间的关系式进行数值迭代求解,来寻找轴承受载后内部的平衡状态.通过与典型有限元分析结果的比较可以看出:所提方法不仅详细计算出了轴承内部的载荷情况,而且更为准确地分析了联合载荷对轴承变形的影响机制.搭建了模拟联合外载荷工况的轴承试验台,测量了轴承的变形,验证了该方法的正确性. 相似文献
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滚珠丝杠作为机床伺服进给系统的重要元件,其热变形会降低伺服进给系统的定位精度,在机床高速化发展的过程中,滚珠丝杠热变形成为其发展的瓶颈,采用通有冷却介质的空心滚珠丝杠为解决这一问题提供了方法。空心滚珠丝杠定位精度受到以下因素影响:滚珠丝杠轴向载荷、转速、通入空心滚珠丝杠的冷却介质的种类、冷却介质流速以及空心滚珠丝杠内孔的大小,这些因素不仅影响空心滚珠丝杠的冷却效果,而且对空心滚珠丝杠的变形也有很大的影响。研究结果表明:轴向载荷和转速对温度影响较小;专业冷却油更适合用于滚珠丝杠的冷却,合理控制其温升和热变形;热变形和热-结构耦合的分析,给出了最佳内孔直径。为空心滚珠丝杠的设计及研究提供理论依据。 相似文献
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In order to create a higher torque spindle system for productive milling operations, rotational speed stability against the torque disturbance has been studied with respect to the spindle mechanical design parameters, actuator types and spindle control algorithms. The study showed a remarkable difference in the spindle rotational speed stability against torque disturbance between a spindle system equipped with an induction servo motor and a permanent magnet synchronous servo motor. The results of this study have been obtained by theoretical analysis, numerical simulation and physical experiments, and the experimental study showed that the hybrid actuation spindle achieves longer tool life. 相似文献