Publisher’s Note
Just as with other mechanical components, oil analysis can help drive reliability and uptime in gear systems. This predictive maintenance technology is one of several available tools that can aid in identifying when failure-related symptoms begin to occur. When you monitor the condition of gear-related lubricants, it will be imperative to ensure they maintain the proper viscosity, sufficient film strength, corrosion control, demulsibility and chemical stability characteristics.
While it may seem overwhelming to identify which oil analysis tests to perform, information on this subject can often be obtained by contacting the OEM supplier, oil analysis lab, reviewing online reference sources and participating in technology- specific training.
For gearboxes, the standard test slate should include viscosity, moisture, elemental analysis, particle count, ferrous density, oxidation and/or acid number. Exception tests to perform when an oil or machine failure progression is suspected would involve analytical ferrography, extreme-pressure tests and oil characterization by Fourier-transform infrared (FTIR) spectroscopy. The exact tests may vary based on the type of gear drive and lubrication method, but most applications will be closely related.
Mechanical seals are often integral parts of a component or system. If they are not considered when changes are made to the system, leaks, failure or downtime may occur.
Contamination, both from external and internal sources, is a significant issue with seals. Among the parameters associated with contamination to trend in your oil analysis reports would be the particle count number and the ISO cleanliness code. If your sample results return with continual increases in the particle count and low levels of ferrous material, this may lead to seal damage.
Although compatibility typically is only an issue when switching lubricants, it is another concern for seal life. Changing the base oil from mineral to synthetic while altering the additive packages that make up the lubricant can have a dramatic effect on the seals. When changing lubricants, consider not only the compatibility between the two lubricants but also how the new lubricant will react with the seal material. Swelling, erosion, blistering, depolymerization and excessive wear are all possible failure mechanisms when seals and lubricants do not function in a cohesive environment.
Finally, while not technically an oil analysis test parameter, temperature is another key aspect to account for with seals. As an oil’s temperature begins to rise, it not only drastically affects the life of the oil but also impacts seal aging. Although temperature is a factor with almost all components, it is not quite as critical in low-speed gearboxes due to the minimized internal friction and churning We propose to publish periodic articles on automotive lubricants from our next issue. We request the readers to contribute articles / case studies, which would benefit the readers.
As always, we welcome your feedback on how to further improve the content and presentation of our publication,
Stay safe and healthy,
Warm regards,
Udey Dhir
