冷处理和深冷处理在渗碳齿轮件中的应用

通过分析18Cr2Ni4WA和20Cr2Ni4A钢的冷处理和深冷处理工艺过程,经试验确定合理的工艺参数后应用于渗碳齿轮件的实际生产中。结果表明,冷处理和深冷处理后渗碳层表面硬度提高3~5 HRC,并可有效增加淬硬层深度。     

大型直齿锥齿轮的铣削加工方法

直齿锥齿轮一般要在专用机床上加工 ,但能够加工大型直齿锥齿轮的生产企业极少。在龙门铣床上铣削加工大型直齿锥齿轮方法简单易行 ,加工精度能够满足一般使用要求 ,运行平稳。     

基于滑动率最小的渐开线圆柱齿轮传动优化设计

针对渐开线圆柱齿轮传动的设计 ,以一对齿轮副啮合的使用寿命最长为优化设计目标 ,通过调整齿轮的变位系数使齿轮传动的最大滑动率为最小以提高其传动寿命 ,并在此基础上设法使两齿轮最大滑动率相近来使其寿命达到基本一致。探讨了数学模型的建立、算法确定、计算机程序的编制 ,并结合工程实际给出了计算实例     

快速加工圆柱直齿轮的展成拉齿工艺

针对圆柱齿轮传统滚齿、铣齿加工效率偏低的问题,提出了展成拉齿加工的工艺方案,从专用刀具、展成切削原理和加工效率计算等方面入手,从理论上分析了该工艺的优越性,例举了双齿条分度机构改装方案,客观论证了圆柱齿轮展成拉齿加工工艺的成熟可靠性。     

表面技术在模具中的应用

简要述概述了表面处理技术在模具发展中的重要作用。并介绍了模具中应用成熟的表面技术。     

Alkali-activated slag concrete: Fresh and hardened behaviour

The behaviour of fresh and hardened alkali-activated slag (AAS) and OPC concretes was compared and the effect of mixing time assessed. OPC and AAS concrete slump and rheological results proved to differ, particularly when the slag was activated with waterglass (WG). The nature of the alkaline activator was the key determinant in AAS concrete rheology. Bingham models afforded a good fit to all the OPC and AAS concretes. In OPC and NaOH-activated AAS concretes, longer mixing had an adverse effect on rheology while improving hardened performance only slightly. In WG-AAS concrete, longer mixing times, improved mechanical properties and also rheological behaviour was enhanced, in which those conditions were required to break down the microstructure. Longer mixing raised thixotropy in OPC and NaOH-activated AAS concretes, but lowered the value of this parameter in waterglass-activated slag concrete.     

Influence of tooth modifications on tooth contact in face-hobbed spiral bevel gears

In this study the influence of tooth modifications induced by machine tool setting and head-cutter profile variations on tooth contact characteristics in face-hobbed spiral bevel gears is investigated. The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. The modifications of tooth surfaces are introduced into the teeth of both members. The lengthwise crowning of teeth is achieved by applying a slightly bigger radius of lengthwise tooth flank curvature of the crown gear generating the concave side of pinion/gear tooth-surfaces, and by the variation of machine tool settings in the generation of pinion/gear teeth. The ease-off in the tooth height direction of meshing tooth surfaces is achieved by applying a head-cutter whose profile consists of two circular arcs, instead of a straight-line. The method of tooth contact analysis applied determines the path of contact, the potential contact lines, the separations along these lines, and the transmission errors. A computer program implements the method. By using this program the influence of the variation of machine tool settings and of head-cutter geometry on tooth contact is investigated and discussed.     

面向寿命终结阶段的机械产品设计绿色多准则优化

针对机械产品设计过程中通常考虑产品寿命终结阶段(End-of-life,EOL)报废处理过程的可拆卸性、再制造性、环保性等单个绿色质量因素影响,导致机械产品的回收拆解中可重用、回收零部件由于拆解过程费事、费力、经济性差无法回收重用或因回收重用价值不大导致零部件被直接废弃,造成严重的环境污染.从回收拆解作业效率、回收拆解...     

精密伺服机构微型齿轮啮合刚度的有限元辨识

基于微型齿轮重合度大的特点,首先利用齿轮啮合刚度、轮体刚度以及轮齿刚度间的串联关系,建立单齿啮合的有限元模型,计算出单齿啮合时齿轮的啮合刚度以及主、从动轮轮体刚度和轮齿刚度;再引入重合度的影响系数,得到微型齿轮的平均啮合刚度;进一步分析齿轮平均啮合刚度在中心距误差范围内的变化规律,发现当中心距从标准中心距处开始逐步减小时,齿轮平均啮合刚度缓慢增加;当中心距从标准中心距处开始逐步增大时,齿轮平均啮合刚度显著减小。     

某齿轮传动系统生产基地工业设计加工部分

齿轮传动系统作为机械装备的动力传动主体及核心零部件,是国家鼓励发展的产业.详细地论述了某齿轮传动系统生产基地加工部分的工业设计.介绍了该基地建设设计中的主要产品加工工艺流程、主要加工设备选择等加工工艺设计关键技术.该基地已投入生产,技术设备先进,工艺布局合理,具有国内领先水平.