Roundness measurement of spherical artifacts at arbitrary latitude

This technical note examines an approach to measuring the roundness of spherical artifacts at arbitrary latitude. A roundness measurement includes the combined contributions from the artifact’ form error and the spindle’ error motion. We show that it is possible to separate the spindle error from artifact form error at any inclination with respect to the axis of rotation if the axial and radial error motion is independently measured using an error separation technique such as Donaldson reversal. Comparison of the predicted and measured results shows agreement to less than a nanometer.     

Proposal of novel chatter stability indices of spindle speed variation based on its chatter growth characteristics

Chatter is one of the most critical problems that causes poor surface quality and restriction of machining efficiency. Spindle speed variation (SSV) is a well-known technique for suppression of regenerative chatter. However, in the authors’ understanding, the chatter suppression effect diminishes when the spindle speed difference between the present and previous cutting moments is small. Furthermore, the stability changes largely according to the spindle speed variation profile which changes with the set condition of SSV parameters, e.g., nominal spindle speed, variation period and variation amplitude. Therefore, SSV parameters should be adequately set to avoid this limitation and to exert its effect throughout the entire duration of cutting. However, there is no clear methodology to determine the optimal condition. This paper presents the characteristics of chatter growth during SSV focusing on the change of chatter frequency, which lead to novel indices to evaluate the chatter stability when cutting with SSV. To verify the validity of the indices, time-domain simulations and the cutting experiments with triangular spindle speed variation (TSSV) are carried out. The influence of SSV parameters on the chatter stability is investigated from the simulation and experimental results. The limitations of widely utilized SSV profiles are discussed.     

数控弧齿锥齿轮磨齿机主轴系统的谐响应分析

采用有限元分析软件ANSYS ,对YK2 0 4 5型数控弧齿锥齿轮磨齿机主轴系统进行了谐响应分析 ,得出特定工况及不同主轴系统几何参数下的位移频率响应曲线 ,分析了跨距和支承刚度对主轴系统抗振性的影响 ,论文为对主轴系统动态性能的进一步深入研究提供了基础。     

电磁流量计电场动态平衡过程分析

从电磁流量计电场的基本公式出发，分析了电极截面内电场的建立过程及平衡过程，指出涡电流场在电极截面内分布的动态平衡性。结合相应的边界条件，计算了平衡状态下涡电流场的分布及其对传统电磁流量计及多电极电磁流量计测量值的影响。通过数值计算及定量分析，证明了多电极电磁流量计弦端压差测量方法的有效性。该研究有助于深入分析电磁流量计的工作原理及指导多电极电磁流量计的设计。     

流量计的选用

本本文介绍了流量计的分类及如何从数以百计的流量计中选出最为适合自己的流量仪表。为非流量仪表专业人员提供了一种简便易行的选择步序，并从多个角度介绍了影响流量计选择的要素，给出了流量计使用和维护的一些建议。     

高速主轴/刀柄联结特性的有限元分析

非线性有限元法可以分析、模拟主轴 /刀柄联结面间的变形、接触应力分布规律 ,为主轴 /刀柄联结的设计和优化提供理论依据。研究表明 ,适当提高轴向拉力和过盈量可以有效地解决上述问题 ,改善联结性能和加工精度。     

管道坡口整形机的技术与应用

论述了石油管道施工技术的发展以及管道坡口整形机的研制,详细介绍了管道坡口整形机的结构、工作原理、性能以及液压控制技术的应用.     

Particular behavior of spindle thermal deformation by thermal bending

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.     

ZLC－I点速流量计的研制与应用

介绍以流体力学的理论及实验研究为基础，研制出工程中实用的点速流量计。其特点是：结构简单、精度高、成本低、运行稳定可靠、安装维护方便、多通道远传、集中检测、适应范围广。可计量大口径、特大口径因管内牛顿流体紊流流动的流量     

数控机床主轴驱动中的交流电机及其控制策略

对现有的交流电机主轴驱动系统进行了概述。分别就各种形式主轴电机的结构、效率、控制策略等进行了阐述和对比分析,指出了各种主轴驱动系统的优、缺点和适用领域,并对发展我国交流电机主轴驱动系统提出了几点建议。