Evaluation of Extreme Pressure and Anti-Wear Properties Using a Translatory Oscillation Tribometer (SRV®) to Screen Gear Oils for Scuffing Loading Testing
Dr. Raj Shah - Koehler Instrument Company, Inc.
- Stanley Zhang - Koehler Instrument Company, Inc
Gear oils are a category of high viscosity lubricants primarily used for transmissions and differentials in automobiles or other industrial machinery. It is common practice for gear lubricants to contain various additives to enhance their load-carrying capacity and performance in specific applications. In particular, machinery operating under heavy load, slow speed conditions often require anti scuff gear lubricants or extreme pressure (EP) lubricants to provide protection against adhesive and frictional wear. The Translatory Oscillation Tribometer (SRV®) is an invaluable instrument for evaluating friction and wear properties which can be applied to EP and anti-wear (AW) testing of gear oils. EP and AW tests are conducted on a translatory oscillation tester equipped for parallel movement, following the methodology of DIN 51834-4. The results are able to characterize and differentiate gear oils based on their EP and AW properties, which can serve as a pre-screener to determine which oils should go on for further bench tests and field use. This allows the SRV® Tribometer to function as a tool to screen gear oils and narrow down which gear oils should undergo expensive and time-consuming tests, such as the FZG standard scuffing loading test, which measures the scuffing load capacity of lubricants as per ISO 14635. In addition to pre-screening gear oils, the SRV® Tribometer is capable of yielding results for the coefficient of friction, wear volume and estimations for the load carrying capacity. This poster will show how the tests were developed, how the results compare to the FZG scuffing load test and how the SRV® Tribometer can be used to provide a meaningful evaluation of gear oils.