ZSX-23型轴环式数显装置在坐标磨床上的应用

我厂的M2932单柱坐标磨床用于高精度坐标孔距、并经淬火后的直孔、锥孔,圆弧曲线和键槽的磨削加工。在磨削过程中,手轮(刻度盘)每转一圈,磨轮径向进刀量直径为0.12mm,该机床径向进给最大精细调整量为1.3mm,因此,手轮(刻度盘)在磨削加工过程中需要连续旋转十几圈。

一种新型的轴环式容栅数显表

容栅数显是近几年发展起来的一项测量技术,特别是制成容栅系统的专用的大规模集成电路后,一片芯片就能完成测量、数据处理、显示全部工作,使容栅数显成为一个结构简单、功能完善,功耗极低的小型数显系统,并应用于机械工业中,开发了容栅数显卡尺及国内最近研制的轴环式容栅数显表。

轴环式数显装置的安装和使用

目前,我国已有四大类型的数显装置,即感应同步器、光栅、磁(?)和容栅。轴环式数显表属于光栅类,它正广泛应用于卧式车床、铣床和磨床等机床上,安装于控制拖板运动的刻度盘的位置,通过进给丝杠的转动反映加工过程中的进给量。它与其它数显装置相比,改造费用低、安装时间短。

轴环式数显表在C630车床上的应用

轴环式数显表(以下简称为轴环表)是一种测量直线和角度位移的数字化仪表。适用于机床的进给和定位测量,可直观的读出进给尺寸。目前一般用轴环表改造车床的方式有两种: 一是将机床中拖板丝杠重新加长制作,或者利用原丝杠采用轴套接长,再安装轴环表。其缺点:

三轴环板式永磁齿轮气隙磁场及转矩计算

利用标量磁位法获得了三轴环板式永磁齿轮(Triple-shaft Ring-plate Magnet Gear,TRMG)的气隙磁场数理模型,根据磁场叠加原理建立了内、外永磁圈间气隙磁场及其相应的电磁转矩模型;由于所有计算均基于TRMG的平面磁场建立,因此,所建模型与二维有限元结果间具有较高的准确度(误差≤5%);其计算速度远快于三维有限元法,且与二维及三维有限元分析具有较好的吻合度与趋势性,验证了所建模型的准确性,可适用于三轴以上的多轴环板式永磁齿轮的磁场分析与结构动力学计算。

平行轴少齿差环式减速器动平衡研究

对 N型内齿行星齿轮传动的基本结构形式——环式减速器的传动机理进行了分析研究 ,建立了环式减速器系统受力分析模型 ,得出目前环式减速器存在惯性力或惯性矩不平衡的结论。提出了一种能实现惯性力和惯性力矩平衡的平衡环式减速器以及在工艺上具体实现的措施。试验证明 ,平衡式环式减速器与同功率其他环式减速器相比具有振动噪声小的优点 ,同时降低了减速器制造成本和加工难度 ,具有重要的理论意义和工程实用价值。

THE STATIC PERFORMANOE AND PARAMETER STUDY OF FLOATING-RING HYDRODYNAMIC THRUST BEARINGS

In this paper, floating--ring thrust bearings are investigated. A mathematical model is established to analyze the static performance of this kind of bearings, such as the load capacity, frictional power loss, temperature rise as well as the angular speed ratio between the floating ring and runner.Meanwhile, a parameter study is also conducted on the characteristics of floating-ring thrust bearings.Finally, the theoretical calculation results are verified by experiments.

Strength failure and crack coalescence behavior of sandstone containing single pre-cut fissure under coupled stress, fluid flow and changing chemical environment

In order to study the strength failure and crack coalescence characteristics of cracked rocks, uniaxial compression experiments were conducted on cylindrical sandstone specimens, sampled from Longyou Grottoes of Zhejiang Province, China, with a single pre-cut crack soaking in different chemical solutions. Based on the results of uniaxial compressive test under different chemical solutions and velocities of flow, the effect of strength and deformation characteristics and main modes of crack coalescence for cracked rocks under chemical corrosion were analyzed. The results show that the pH value and velocity of the chemical solutions both have great influence on the sandstone sample's uniaxial compressive strength and deformation characteristics. Cracked sandstone samples are tension-destructed under uniaxial compression, and the crack propagation directions are consistent with the loading direction. The phenomena of crack initiation, propagation and coalescence of sandstone are well observed. Four different crack types are identified based on the crack propagation mechanism by analyzing the ultimate failure modes of sandstone containing a single pre-cut fissure. The failure process of specimen in air is similar with the specimen under chemical solutions, however, the initial time of crack occuring in specimen under chemical solutions is generally earlier than that in the natural specimen, and the crack propagation and coalescence process of specimen under chemical solutions are longer than those of the natural specimen due to softening of structure of rock caused by hydro-chemical action. Immersion velocity of flow and chemical solutions does not have influence on the ultimate modes of crack coalescence.

Geodesic Acoustic Mode in Toroidally Axisymmetric Plasmas with Non-Circular Cross Sections

The geodesic acoustic mode （GAM）, first predicted by Winsor, Johnson and Dawson in an attempt to explain some experimentally observed low frequency oscillations in stellarators, is a special electrostatic fluid mode with low mode number and coupled with the so-called geodesic curvature of a toroidally confined plasma. The recent on this mode are due to the close relevance of the stabi- lization of drift turbulence by both the zonal flow and the GAM. Previously, the GAM was illustrated in very simple geometries,