Research advances in wet multi-plate clutches and the significance of groove structure in research

Wet clutch, as a transmission system, plays a critical role in many mechanical applications, such as those in vehicles, ships, and helicopters. The performance of wet clutches significantly affects the overall transmission performance. Since their inception, wet multi-plate clutches have been a focal point of clutch research. With the widespread application of wet clutches, research in this area has become increasingly extensive and in-depth. Researchers have investigated the thermal characteristics of frictional pairs during engagement, by noting a sharp increase in frictional heat. To enhance vehicle smoothness during starting and shifting, friction and wear characteristics have also been studied. Additionally, considering the service life and safety of automobiles, researchers have conducted studies on life prediction of clutches. In wet dual-clutch systems, drag torque exists, impacting the control precision of torque transmission, vehicle transmission efficiency, and performance during starting and shifting. Researchers have also examined the characteristics of drag torque. This paper reviews recent advances in wet clutch research, analyzes the influence of friction plate groove structures on four research directions, and suggests that groove structure optimization should simultaneously consider its impact on all four areas.