基于最小势能原理的双渐开线齿轮载荷分布研究

双渐开线齿轮接触线上的载荷非均匀分布,使得载荷计算困难。采用现有的方法或过于简化导致精度不足,或过于复杂使得计算量大、耗时长,并不适用于双渐开线齿轮载荷分布研究。为此,将双渐开线齿轮接触线等分为若干段,建立了双渐开线齿轮载荷分布模型,综合有限元法对轮齿载荷分布进行了研究。首先,根据双渐开线齿轮的啮合特点,求解了时变接触线,将每一啮合时刻下的齿轮接触线“分段”;然后,基于最小势能原理,建立了双渐开线齿轮的载荷分布模型,综合有限元法对齿轮轮齿载荷分布进行了研究;最后,对双渐开线齿轮与普通渐开线齿轮的载荷分布进行了对比分析,并研究了输入扭矩、齿宽对双渐开线齿轮轮齿载荷分布的影响。研究结果表明:载荷分布模型与有限元仿真结果之间的误差在10%之内,载荷分布模型合理可靠;双渐开线齿轮沿接触线方向载荷分布不均匀,节线附近载荷值最大;同参数、同工况下的双渐开线齿轮载荷波动幅度小于普通渐开线齿轮;输入扭矩增加,双渐开线齿轮节线附近载荷分布发生突变;齿宽增加,双渐开线齿轮沿接触线载荷分布不均匀程度增加。

精确成形的大模数内啮合传动的啮合性能分析

目前 ,大模数内齿轮的加工在国内是一个急待解决的难题。为了解决这个难题 ,作者研究了一种与传统加工完全不同的新型加工方法———精确成形法。本文根据共轭原理 ,求出与内齿轮相啮合的外齿轮齿形 ,并将其与渐开线齿形进行比较 ,然后对精确成形的大模数内啮合传动的啮合性能进行了理论分析 ,并通过具体实例计算出诱导法曲率、润滑角及接触线分布。结果表明 ,精确成形的大模数内啮合传动的诱导法曲率小 ,润滑角等于90° ,接触线分布较均匀 。

精轧机压下装置平面二包蜗轮副参数优化

热轧精轧机压下装置传动机构是轧机的重要部件。二级减速原品采用的是美国产Hindley蜗杆传动。经过改造后采用平面二次包络蜗轮副传动。分析了直廓环面蜗杆传动和平面二次包络蜗轮副传动的优点 ,并推导了平面二次包络蜗轮副传动接触线方程。在此基础上 ,通过对蜗轮副不同参数情况下接触线的分析 ,对蜗轮副参数进行优化 。

Analysis of a load application point in spline coupling teeth

The objective of this paper is to investigate the position of the resultant force in involute spline coupling teeth due to the contact pressure distribution for both ideal and misaligned conditions. In general, spline coupling teeth are in contact all along the involute profile and the load is far from uniform along the contact line. Theoretical models available in publications consider the resultant contact force as it is applied at the pitch diameter, and this study aims to evaluate the error introduced within the confines of a common approximation environment. This analysis is carried out through using finite element method （FEM） models, considering spline couplings in both ideal and misaligned conditions. Results show that the differences between the load application diameter and pitch diameter are not very obvious in both ideal and misaligned conditions; however, this ap- proximation becomes more important for the calculation of the tooth stiffness.

Failure mechanism of full-size concrete filled steel circle and square tubes under uniaxial compression

In this paper, the failure mechanisms of full-size concrete filled steel tubes(CFST) under uniaxial compression were investigated with nonlinear finite element method. Existing experimental results were employed to verify the validity of the finite element models of CFST specimens. Then, the numerical analysis was further conducted to study the mechanical behaviors of full-size CFST columns with circular and square cross sections under uniaxial compression. The simulation results indicate that the distribution of the contact pressure between circular steel tube and core concrete is much more uniform than that between square steel tube and concrete, resulting in much higher confinement and more efficient interaction between steel tube and core concrete in circular CFST columns, as well as ultimate load capacity and ultimate displacement. Extensive parametric analysis was also conducted to examine the effect of various parameters on the uniaxial compression behaviors of circular and square CFST columns.