微载荷含油轴承摩擦性能研究 Ⅱ.摩擦试验分析

采用自行研制的径向轴承微载荷摩擦试验机研究了微载荷下径向含油轴承的摩擦性能，采用小波方法对试验数据进行滤波降噪．结果表明，含油轴承在稳定微载荷状态下的瞬态摩擦系数不固定，且随着润滑剂、轴承转速、径向载荷与混合润滑状态等因素而变化．在微载荷状态下，当600r／min、采用液晶添加剂（5CB）与46号机械油以体积比1％-2％配制的润滑剂润滑时，平均摩擦系数达到最小值；当转速从600r／min增至3000r／min时，平均摩擦系数由小变大、再变小；瞬态摩擦系数随着载荷从0．5N增至10．0N呈现高-低-稳定的变化趋势．与混合润滑状态相比，充分润滑下的摩擦系数较大；当混合润滑时，在主轴转速为1500—2400r／min下的摩擦系数出现不稳定．

不同工况参数对酚醛树脂基无石棉闸瓦材料摩擦性能影响

针对WSM–3型酚醛树脂基无石棉摩阻材料,搭建实验装置研究WSM–3型闸瓦材料与16Mn钢摩擦副摩擦性能。根据实验数据,研究了瞬态/平均摩擦系数随不同接触压力、不同滑动速度及不同接触表面温度的变化规律,在考察多种曲线的基础上,分析瞬态/平均摩擦系数在不同工况参数下的变化特性,并探讨了闸瓦材料摩擦性能的变化机制。实验证实,闸瓦材料的摩擦性能不仅具有强烈的系统依赖性,而且与系统的工况因素具有强耦合性,在闸瓦材料摩擦学设计中将瞬态/平均摩擦系数视作变量是必要的。

Thermo-structural analysis on evaluating effects of friction and transient heat transfer on performance of gears in high-precision assemblies

The high precision assemblies with considerable radial interference should be accompanied by heating and cooling processes.However,the mechanical properties of metals are greatly affected by thermal operations.So,for evaluating the stress distribution and distortion of teeth profiles in a gear/shaft assembly,a transient thermal analysis is necessary for finding the change in mechanical properties.The friction on the contact surface is another important parameter in interaction of the gear with the shaft.Evaluating the gear stress and deformation fields for several modes of heat transfer and friction coefficients showed that the maximum radial or tangential stresses on contact surface of the joint may have more than 8%increase by increasing friction coefficient;while the intensity of heat transfer at cooling stage has lower effect on stress distribution.