A Review of the Lubrication Status of Gears Under Dry Running Conditions

In certain operational conditions, gear transmission systems are susceptible to oil leakage, which can result in a loss of lubrication. This degradation of the lubrication condition within the reducer leads to a significant increase in temperature, which can induce gear surface scuffing and ultimately lead to gear transmission failure. Thus, it is crucial to investigate the mechanism of lubrication failure in gears during this process to enhance the reliability and performance of gear transmission systems. Based on the theory of gear Elastohydrodynamic Lubrication, according to the research steps of establishing gear surface equation, obtaining contact trace and load distribution factor, and then deducing entrainment speed and gear surface contact area, the research on key parameters analysis of gear contact and Elastohydrodynamic Lubrication is summarized. Next, the construction and solution methods of the Elastohydrodynamic Lubrication control equation of the gear are analyzed, the advantages and disadvantages of each solution method are compared, the Elastohydrodynamic Lubrication modeling is completed, and the influence of changes in key parameters on the lubrication characteristics of the gear is analyzed. Furthermore, the research on gear lubrication under dry-running conditions is reviewed, and gear lubrication failure prediction and fluid mechanics simulation methods are analyzed. Finally, the development trend of this research field is projected. This provides a reference for the study of gear dry running.