Effect of ATF temperature on the friction-wear characteristic of a wet multi-disc clutch during the running-in process

Abstract

Purpose This paper aims to explore the effect of automatic transmission fluid (ATF) temperature on the dynamic friction-wear properties of the friction component in a wet multi-disc clutch during the running-in process. Design/methodology/approach The running-in evolution was explored in terms of global friction performance and instantaneous friction characteristics. The variation of friction torque of the initial 300 engagement cycles was obtained by wet-clutch tests. Finally, an optical microscope was used to detect the wear mechanism of friction surfaces. Findings The ATF temperature showed a significant effect on the friction-wear performance in the clutch running-in process. The mean coefficient of friction decreased with the increase of the ATF temperature and decreased rapidly in the approximately initial 60 clutch engagements. The higher the ATF temperature was, the thinner the ATF film was, and more asperity summits were cut, thus leading to a smoother surface. Considering the slightly instantaneous friction fluctuation and the wear performance, a proper ATF temperature is necessary. Originality/value The results provide theoretical guidance for selecting the optimal ATF temperature during the running-in process.

Research on self-healing characteristic and state prediction method of the copper based powder metallurgy materials on friction interface

“…Conversely, the H increases from 29.6 HRF to 37.6 HRF, a rise of 27.03%. Moreover, the variation of S is similar to the literature [32] in that both decrease with increasing temperature.…”

Influence of applied pressure on the tribological behaviors of a wet multi-disc clutch during the running-in process

“…Figure 2 shows the variation of dynamic parameters during one engagement cycle of the clutch, where the friction status gradually changes from dynamic lubrication to mixed lubrication and then boundary lubrication. According to the friction behavior of the clutch, the friction torque curve is usually divided into three stages: preparation Stage I, stable growth Stage II and exponential growth Stage III (Yu et al , 2020; Ma et al , 2022). The evolutionary process of the running-in is explored from two perspectives: the global friction performance and the instantaneous friction characteristics of Stage II.…”

Friction Coefficient of Wet Clutches as a Function of Service Mileage

“…Finally, in terms of the friction material p et al [19] and Zhang et al [20] respectively studied the influence of phenolic and glass fiber content in friction materials on the friction characteristics of In addition to the internal factors above-mentioned, the actual exter conditions will also have an influence on the friction coefficient of the wet fore, Ingram et al [21] used experiments to investigate the influence of clu ference on the friction coefficient of wet clutches. Ma et al [22] focused on influence of lubricant temperature on the friction coefficient of wet clutches experimentally investigated the influence of different operating conditions o coefficient of wet clutches. In addition, based on the experimental data of f cients under different operating conditions, Cui et al [24] and Wu et al [25] more accurate dynamic model of friction torque.…”

“…Therefore, Ingram et al [21] used experiments to investigate the influence of clutch speed difference on the friction coefficient of wet clutches. Ma et al [22] focused on exploring the influence of lubricant temperature on the friction coefficient of wet clutches. Li et al [23] experimentally investigated the influence of different operating conditions on the friction coefficient of wet clutches.…”