基于光滑粒子流体动力学的滑油泵数值仿真

基于光滑粒子流体动力学方法,构建齿轮泵壳体及内部流体的粒子模型,对内啮合齿轮泵在不同工况下的流量特性进行数值模拟。首先设置了均匀分布的油泵出入口压强,计算得到的流量结果与试验结果吻合,且在中低转速下流量与转速呈线性关系;针对高转速下油泵流量降低的问题,通过适当减小周期模型内部的流体粒子数反映流量降低,获得了与试验值相吻合的连续转速流量的模拟结果;针对影响齿轮泵性能的间隙和空化现象,结合模型特点给出了相应的近似处理方法。通过以上研究,将SPH方法成功地应用于滑油泵问题的分析计算。     

Review on contact simulation of beveloid and cycloid gears and application of a modern approach to treat deformations

Gear drives are key components for all kinds of machines as well as of industrial equipment. Therein, beveloid gears and cycloid gears are increasingly used in industry. Gaining a more comprehensive understanding of those types of gears is essential. However, the measurement of the dynamic response of these gears is not an option due to the high cost of the required experiments. Along with the development of computer technology, several numerical tools and methods to study gears with standard and non-standard flank profiles have been introduced. Various works related to standard gears or beveloid and cycloid gears have been published. In this study, a contemporary review about the modelling and contact simulation of beveloid and cycloid gear drives will be given. Some studies will also be introduced to present an efficient approach to simulate contact forces and contact characteristics of gear wheels with standard and non-standard tooth profiles considering deformations too.     

Critical shimmy speed of nonswiveling landing-gear wheels subject to lateral loading

The paper presents a nonlinear model describing vibration of the landing gear relative to the fuselage. The model is intended to analyze the dynamic stability of nonswiveling main-gear wheels. The model is used to show that the lateral component of the fuselage speed has a significant effect on the critical shimmy speed __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 9, pp. 134–142, September 2006.     

干摩擦条件下聚甲醛塑料动力齿轮传动啮合效率的分析研究与计算

从高分子材料的粘弹性力学模型出发，推导出塑料与钢齿轮副粘滞发热损耗功率的计算公式，并以此为基础，结合塑料材料的弹性模量和滑动摩擦系数的测试数据，考虑温度、弹性模量、摩擦系数及载荷之间复杂的偶合关系，研究并提出了一种在干摩擦条件下塑料与钢齿轮副啮合效率的数值计算方法，运用这种方法，可以方便地获得任意啮合位置的瞬时啮合效率及一个啮合循环中的平均啮合效率，通过对聚甲醛与４５＾＃钢齿轮副的计算发现，在干摩     

聚四氟乙烯对齿轮润滑成膜膏润滑性能的影响

作者以聚四氟乙烯(PTFE)为固体润滑剂填料对GM型齿轮润滑成膜膏进行了改进,并且研制出了两种新的成膜膏系列产品。经四球试验机、动静摩擦系数精密测定仪和SRV试验机评价的结果表明,添加PTFE的GM-2型成膜膏的承载能力和减磨性能都明显地比未添加的好;以PTFE为主要固体润滑剂填料的GM-3和MFC-1型两种润滑成膜膏也都具有良好的润滑性能,其中后者的性能与含PTFE的GM-2型成膜膏的接近。通过对摩擦轨迹的电子探针检测发现,PTFE在摩擦过程中于摩擦表面形成了转移膜,因而改善了润滑成膜膏的摩擦学性能。     

山地输电线动刚度计算及模态分析

为了揭示地形变化对连续档输电线动态特性的影响，本文提出了基于任意高差角的动刚度理论．首先将单档导线视为连续档导线的子结构，构建了两悬挂点不等高的单档导线振动方程，并在该理论方程中引入了二次项，能够考虑重力沿弦向分量的影响，推导出绝缘子串绕其悬挂点转动的动刚度计算方法，通过动刚度理论研究连续档导线横向振动模态和频率，并应用有限元软件ABAQUS 验证理论模态和频率公式的准确性．所得结果表明，动刚度的计算方法具有较高的精度，理论模态与有限元输出结果吻合较好，同时获得的频率和模态可为山地高压输电线路防舞技术的研究提供依据．     

齿轮有限元强度计算的单元自动生成

本文提出了一种专用于齿轮有限元强度计算的单元自动生成办法,只需输入法截面内一半数据,便可自动生成空间二十节点等参元的全部数据。本文严格地以实际齿面方程所描述的齿廓曲面体为计算对象,并按轮齿法截面划分单元,也适合于其他柱面体和螺旋面体的有限元计算。     

高压下受限齿轮油成膜特性研究

本文揭示了在实际应用中极端工况下齿轮油的润滑特性.为了测量在高接触压力和不同温度条件下齿轮油的成膜能力,制作了高精度的膜厚测量仪,采用相对光强法实现纳米级膜厚测量.试验中共采用了5种性质不同的齿轮油,在纯滚动条件下测量接触区的油膜厚度,结果表明：随着接触压力的升高油膜厚度明显降低,但压力对润滑状态影响不大;温度的改变不但能影响油膜厚度,对润滑状态的影响也很明显;GL-5 85W/190和GL-5 85W/90齿轮油在接触压力达3 GPa温度提高到120℃时仍能形成很厚的油膜,但其余3种润滑剂在极端工况下成膜能力不足.本文最后根据试验结果还提出了含有丰富添加剂的齿轮油润滑模型.     

谐波齿轮减速器啮合状况研究

谐波齿轮减速器的工作性能与其啮合状况有密切联系，而啮合状况又与减速器的几何参数、柔轮变形状况有关。本文在考虑柔轮二维变形条件下，上机计算了减速器不受载荷时的轮齿侧隙分布情况及受载时的啮合击数、啮合力分布规律，计算结果与实际情况相符。这为改进减速器的设计、提高其工作性能打下了良好的基础。     

A method for calculating static transmission errors of plastic spur gears using FEM evaluation

There are many ways to calculate the static transmission errors of steel gears, but none is developed for plastic gears. Since the Young's modulus of the plastic material is lower than that of steel by two orders, the effects of large tooth deflection on the static transmission errors of plastic gears become significant. A multi-tooth contact analysis using finite element method for calculating the static transmission errors of plastic spur gears is established to compare with the existing method for steel spur gears. According to the comparison results, a modification of the existing method is proposed for plastic spur gears and verified by the same finite element contact analysis.