湿式离合器接合过程中的热弹性稳定性

Thermoelastic stability of wet clutches during engaging process

针对湿式离合器接合过程中的局部高温区及影响因素,利用热弹性不稳定性理论(TEI)进行了理论建模与分析。模型中考虑了材料表面粗糙度和混合润滑对摩擦副温度和压力的影响,分析了混合润滑状态下润滑区域与接触区域的比例以及油膜剪切热量与摩擦热量的比例。为了准确测量材料表面粗糙度,设计台架试验,利用表面形貌仪测试了对偶片表面形貌,分析了粗糙度在离合器不同使用阶段的变化规律。结果表明,当离合器接合转速超过临界值时,温度场分布出现明显的波动,高、低温区间隔分布。同时,指出了离合器摩擦材料参数(导热性、弹性)与结构参数(对偶片厚度)对稳定性的影响。

Abstra investi effects ct ： On gate t of th the basis of Thermoelastic Instabilit he local hot zones and influence fac e surface roughness and the mixed y （TEI） th tots of wet lubrication eory, a theoretical model is propo clutches during engaging process on the temperature and pressure sed to ~ The of the friction pair are considered. Under mixed lubrication, the ratios of the lubrication area to the contact area and the fluid shear velocity induced heat flux to the frictional heat flux are calculated. A plasmon resonance analyzer is used to investigate the variation of the surface roughness in different stages~ The results show that strong inhomogenous temperature field, hot zones and cold zones appear when the clutch engaging speed exceeds the threshold. The material properties, such as thermal conductivity and elasticity, and structural properties, such as the thickness of the matting disk, significantly influence the stability of the system. Key words： vehicle engineering; wet clutch; thermoelastic instability; surface roughness; mixed lubrication; hot spots