为研究缸套变形对活塞环与缸套摩擦学性能的影响,提出缸套内径实际非圆轮廓的缸套与活塞环间油膜厚度周向分布的理论和计算方法.采用连续梁三弯矩方程,通过求解燃气压力、活塞环张紧力与油膜支反力共同作用下的活塞环变形平衡方程,获得油膜厚度沿活塞环周向的非均匀分布.结果表明:缸套与活塞环日间润滑油膜厚度的周向分布既与作用在活塞环上的载荷有关,也与缸套的变形大小及轮廓形态密切相关.吸气冲程的上死点位置,4个缸的缸套与活塞环之间周向油膜厚度的最小值、最大值和均值的最大比值分别达到1.08、1.78、1.37.非圆缸套下轴向各截面油膜周向均值较相应的理想圆形缸套的油膜厚度大一些.%In order to investigate the effect of non-circular of cylinder bore on tribological properties of oil film between cylinder and piston ring, a new theory and method to calculate oil film thickness between piston ring and cylinder was presented, considering non-circular of the cylinder bore in firing condition. The deformation of the piston ring was obtained using three moment equations on continuous beam to get the equilibrium of forces on it including gas pressure, ring tension and supporting force from oil film, afterwards, the oil film thickness between piston ring and cylinder was calculated. Results indicated that distribution of the film thickness between piston ring and cylinder along the circumferential direction not only was affected by forces on it, but also had a close relationship with shape and magnitude of cylinder deformation. At top dead moment in suction stroke, the maximum ratios of minimum value, maximum value and mean value of oil film thickness along circumferential direction in four different cylinders reached 1.08, 1.78, 1.37 respectively. Comparing with that between piston ring and ideal round cylinder, mean value of oil film thickness along circumferential direction between piston ring and non-circular cylinder bore was bigger.
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