| Summary: | 碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 101 === In this study, a theoretical model is proposed to predict the thermal effects on the elastohydrodynamic lubrication behavior of line contacts under the lubricant starvation. The film thickness and the oil temperature are calculated by the modified Reynolds and energy equations in the supply region (before the oil flows through the Hertzian contact) at the fixed flow rate and the lubricant starvation conditions. The effect of flow rate on the oil temperature is investigated.
Results show that the film thickness at the supply region increases with increasing the flow rate at different slip ratios, so that the location of the meniscus gradually moves to upstream. Consequently, the friction coefficient and the surface temperature of roller are decreased. When the flow rate is much smaller at the severe starvation conditions, the temperatures of the oil and the roller increase. When the flow rate is large than that of the fully flooded conditions, the oil flows back, so that more heat is taken away. The fresh oil has better cooling effect on the roller. Consequently, the oil temperature and the surface temperatures of the rollers at the pressure region is relatively low. Finally , the formula of the surface temperature at the upper and lower rollers in the outlet region is derived.
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