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在活塞式发动机上,缸套温度对于摩擦和润滑油油膜厚度的影响最为强烈。随着缸套温度的升高,流体动力的摩擦力和因此而引起的摩擦损失减少。同时,活塞环上的润滑油油膜厚度减薄,上止点和下止点换向部位的混合摩擦力增大,磨损增大。 缸套温度不变的情况下,随着转速提高,流体动力的摩擦力和摩擦损失增加。油膜增厚,混合摩擦力减小,磨损也减较。 缸套温度相同的情况下,压力负荷增大,油膜厚度变薄,尤其是在膨胀冲程时,混合摩擦力增强,同时磨损也增加。 在几种试验用的第一道压缩环的轮廓线之中,对于摩擦、磨损和润滑油控制来说,有一种最佳的断面轮廓线。在目前工作情况下,这是与经过了大量研究且在长期运用实践中成熟了的环截面的试验结果相符的。 摩擦和油膜厚度、混合摩擦力和环与缸套磨损比率、以及油膜厚度和油耗之间的相互关系表明,利用此种类型的试验装置,能够准确地测得有关的物理关系并且可以应用在批量生产的发动机上。
On piston engines, liner temperatures have the most effect on friction and lubricant film thickness. As the cylinder liner temperature increases, hydrodynamic friction and hence friction losses decrease. At the same time, the thickness of the lubricating oil film on the piston ring is reduced, the friction between the top dead center and the bottom dead center is increased, and the wear is increased. With constant cylinder liner temperature, hydrodynamic friction and frictional losses increase as the rotational speed increases. Film thickening, mixing friction decreases, wear is also reduced. When the cylinder liner temperature is the same, the pressure load is increased and the thickness of the oil film is thinned. Especially in the expansion stroke, the friction of the mixture is enhanced and the wear is also increased. Among the profiles of the first compression ring used for several tests, there is an optimal profile for friction, wear and lubricant control. In the present case, this is in line with the experimental results of a large number of studies and of the mature ring sections in long-term practice. The relationship between friction and oil film thickness, mixed friction and ring-to-liner wear ratio, and film thickness and fuel consumption indicate that with this type of testing device the relevant physical relationships can be accurately measured and can be applied in batch Production of the engine.