Suface Failure Prevention Method at the Start-Stop of CVT

CVT启停时表面故障的预防方法

基本信息

批准号：
14550127
负责人：
OHNO Nobuyoshi
金额：
$ 2.18万
依托单位：
Saga University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550127/
关键词：
Tribology t-CVT EHL Traction oil Solidification Rheology High pressure Phase diagram

项目摘要

1.High-Pressure Rheology of Eight Synthetic Lubricants Based on Phase DiagramsThe phase diagram was first plotted for oils, up to pressure L2GPa and temperature from 303K to 353K using the high pressure density experiment results and others. The high pressure viscosity experiment was done for oils. Then the relationship between pressure=temperature with density and viscosity was proposed based on free volume theory. It was found that the new equations from these relationships could predict the high pressure rheology more closely than that of Dowson and Roelands. Moreover it was shown that the Ehrenfest equation or the gradient of the phase diagram is closely related to the expansion coefficient of free volume.2.High-Pressure Short Time Behavior of Traction FluidsThe squeeze film formation ability of traction fluids is studied under impact load by falling bearing steel ball against a flat anvil made of mild steel. The effect of the pressure-viscosity coefficient and the viscosity is inv … More estigated for plastic impact. The difference of depth of the lubricated surface dent and the dry dent increases linearly with the product αη of the pressure-viscosity coefficient a and the viscosity η The importance of lubricant parameter αη is observed under the squeeze film formation ability from contact voltage or EHL central film thickness measurement at rolling condition. The intensity of each impact collision is measured by means of an acoustic emission (AE) sensor. The high-pressure short time solidification of traction fluids were confirmed by the analysis of dent after the impact tests and AE analysis under impact loads.3.Surface Failure Prevention Method at Halting of t-CVTA method based on interferometry has been developed for experimentally measuring transient, changes in EHD film thickness in non-steady state conditions. At present the method obtains 125 film thickness or film profile measurements per second by using a high speed digital video camera. In EHL shut down, the entrapments of oil form upon halting. The entrapped film thickness increases linearly with the product αη a of pressure-viscosity coefficient α, the viscosity n and the deceleration a. The subsequent leakage of oil from contact is fluid specific. The periods of squeeze out of entrapped oils are conditioned by the product α p of mean Hertzian pressure p and the pressure-viscosity coefficients α of oils. Less

1.基于相图的八种合成润滑油的高压流变学首先利用高压密度实验结果和其他结果绘制了压力高达L2GPa和温度从303K到353K的油的相图。然后根据自由体积理论提出了压力=温度与密度和粘度之间的关系，并从这些关系中发现了新的方程。可以比Dowson和Roelands更准确地预测高压流变性，并且表明Ehrenfest方程或相图的梯度与自由体积膨胀系数密切相关。2.高压短时行为。牵引液通过将轴承钢球落到由低碳钢制成的平砧上，研究牵引液在冲击载荷下的挤压成膜能力。压力-粘度系数和粘度的影响是相反的。润滑表面凹痕和干燥凹痕的深度差随着压力粘度系数 a 和粘度 η 的乘积 αη 线性增加。润滑剂参数 αη 的重要性在挤压成膜能力下观察到：通过声发射（AE）传感器测量滚动条件下的接触电压或EHL中心膜厚度来确认牵引液的高压短时间固化。通过冲击试验后的凹痕分析和冲击载荷下的 AE 分析。3.基于干涉测量法的 t-CVTA 方法停止时的表面失效预防方法已开发出来，用于实验测量非稳态下 EHD 膜厚度的瞬态变化目前，该方法通过使用高速数字摄像机每秒获得 125 次薄膜厚度或薄膜轮廓测量，在 EHL 停机时，油的截留量会线性增加。压力-粘度系数 α 的乘积 αη a、粘度 n 和减速度 a 因接触而产生的油的泄漏是特定于流体的。被截留油的挤出时间由平均赫兹压力的乘积 α p 决定。 p 和油的压力粘度系数 α 较小。