NOK Foundation

<div class="htmlview paragraph">It has recently become popular to enclose gas in shock absorbers in order to improve thier performance. The operating condition of oil seals for shock absorbers, therefore, has been changing, and some problems with frictional characteristics and sealing performance have newly been observed. This paper discusses how the problems are solved experimentally and reviews the countermeasures to prevent such problems before they actually happen.</div>

It is well known that the valve-stem seal has been used for the valve-stem application of automotive engines, and influences the lubricating status between the valve stem and a valve guide. The valve-stem seals are important in controlling consumption of lubricating oil for engines and in preventing air pollution. It is necessary that valve-stem seals have stable controlled oil leakage characteristics, Q (cm3/s), relative to variables such as oil viscosity, shaft speed and shaft-surface roughness. In this paper, characteristics of the controlled oil leakage on valve-stem seals have been discussed by applying an inverse problem of hydrodynamic lubrication.