EHL test machine for measuring lubricant film thickness and traction

摘要

A method and apparatus for measuring thickness and traction properties of elastohydrodynamic lubricant (EHL) films is described. The apparatus utilizes at least one ball or roller loaded against the internal diameter of a transparent ring having a larger radius than said ball or roller. A lubricant is placed between the rotating roller and ring thereby forming an EHL film where the ball and ring contact. Roller and ring rotating speeds are controlled to obtain different amounts of relative sliding motion between their surfaces. Contact between the surfaces and the resultant film are observed via the transparent ring which allows optical measurements of lubricating film thickness. Traction forces generated during contact are measured by any suitable force measuring device.