Liquid/Solid Transition Lubrication in Hertzian Contacts

赫兹接触中的液/固转变润滑

基本信息

批准号：
03650131
负责人：
OHNO Nobuyoshi
金额：
$ 1.34万
依托单位：
Saga University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650131/
关键词：
Herzian contact Lubrication regimes Bulk modulus Free volume Traction Ball bearings Lubricant properties Liquid Solid transition Lubrication ガラス転移潤滑油

项目摘要

(1) The observed minimum film thickness at a rolling contact is plotted in the form of the Greenwood diagram. In the solidification ranges VE (Viscoelastic) and EP (Elastic-Plastic) larger thickness is formed. The upper parts of these thickness curves are limited by the boundary of the PR (Piezoviscous rigid) range defined by Houpert.(2) In the case of traction oils bearing life is hardly related with the film parameter in contrast to mineral oils, which show a general feature that bearing life increases with increasing film parameter.(3) Traction oils having larger pressure-viscosity coefficients and higher coefficients of traction are easily solidified under the operating conditions of bearings.(4) In the case of thrust ball bearings the merit of the solidified films is rather little recognized. They shorten bearing life, increase friction and operating temperature. These facts are related with bulk moduli of solidified films.(5) Demerits of traction oils are attributed to severe operating conditions of thrust ball bearings, which are strongly affected by the presence of spin moment.(6) The solidified oil films of traction oils easily cause breakdown owing to their brittle nature. The brittleness shows a relation reversed to the bulk modulus. It is estimated by measuring the temperature difference between solidified and failure temperature at lowering temperatures.(7) By raising operating temperatures by external heating bearing life is rapidly shortened as the product of the pressure-viscosity coefficient and the average contact pressure is reduced considerably lower than the critical value 25, i.e. necessary to maintain the elastic plastic state.

(1) 以格林伍德图的形式绘制滚动接触处观察到的最小膜厚度。在 VE（粘弹性）和 EP（弹塑性）凝固范围内，形成较大的厚度。这些厚度曲线的上部受到 Houpert 定义的 PR（压电粘性刚性）范围的边界限制。(2) 在牵引油的情况下，与矿物油相比，轴承寿命几乎与油膜参数无关，这表明轴承寿命随着油膜参数的增加而增加。 (3) 具有较大压力粘度系数和较高牵引系数的牵引油在轴承的工作条件下很容易凝固。 (4) 推力球轴承的优点的固化薄膜很少被认可。它们会缩短轴承寿命、增加摩擦和工作温度。这些事实与固化膜的体积模量有关。(5)牵引油的缺点归因于推力球轴承的恶劣工作条件，其受到旋转力矩的存在的强烈影响。(6)牵引油的固化油膜由于其脆性，很容易导致损坏。脆性显示出与体积模量相反的关系。它是通过测量较低温度下的凝固温度和失效温度之间的温差来估算的。(7) 通过外部加热提高工作温度，轴承寿命会迅速缩短，因为压力粘度系数和平均接触压力的乘积会大大降低超过临界值25，即维持弹塑性状态所必需的。