Correlation Study of Different Shear Stability Test Methods for Hydraulic Oils

Abstract

Nowadays, different shear stability test methods for hydraulic oils are favored differently by different original equipment manufacturers (OEMs) or in different regions. Therefore, correlation studies between these test methods are becoming very important. In this articles, the correlations among three popular shear stability test methods for hydraulic oils were investigated. In addition, the relationship between these methods and the pump test was investigated. The results showed that the sonic shear test and bearing shear test showed a good correlation in terms of both viscosity loss and shear stability index (SSI). The viscosity change during the pump test can be reproduced both by sonic and bearing shear test methods and the relationship the between bearing shear test and pump test is almost consistent depending on different data sets.

KEY WORDS:

• Hydraulic oil
• Shear stability
• Correlation