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将三维瞬态热传导模型、动压润滑模型和润滑油膜传热模型耦合起来,并考虑了润滑油的黏-温变化、油膜破裂位置以及活塞环弹力在气缸套圆周方向上的非轴对称性等影响因素,开发了一种活塞环-气缸套三维非稳态热混合润滑摩擦模型.采用上述模型,对比分析了固体部件温度场、活塞环轴向高度和桶面高度3个结构参数对活塞环-气缸套润滑摩擦性能的影响.结果表明:在365.3°CA时,最小油膜厚度取得最小值,摩擦力取得最大值;活塞环、气缸套分别取进气下止点和燃烧上止点处的温度计算出的最小油膜厚度降低的幅度值为31.7%;活塞环轴向高度由2.00,mm增大到4.00,mm,最小油膜厚度增大的幅度值为74.5%,最大摩擦力降低的幅度值为45.7%;活塞环桶面高度由2.5,μm增大到5.0,μm,最小油膜厚度降低的幅度值为46.5%,最大摩擦力增大的幅度值为57.1%.
The three-dimensional transient heat conduction model, dynamic pressure lubrication model and lubricating oil film heat transfer model are coupled, and the visco-temperature variation of lubricant, the cracked position of oil film and the non-axial symmetry of the piston ring in the circumferential direction are considered A three-dimensional unsteady hot-lubricant friction model of piston-cylinder liner was developed.Using the above model, three structural parameters, temperature field of the solid part, axial height of the piston ring and height of the barrel surface, The results show that the minimum oil film thickness reaches the minimum at 365.3 ° CA, and the friction force reaches the maximum value. The piston rings and cylinder liners respectively take the bottom dead center of intake air and the top dead center of combustion The minimum thickness of the oil film calculated by the temperature decrease is 31.7%; the axial height of the piston ring is increased from 2.00 mm to 4.00 mm, the minimum thickness of the oil film is increased by 74.5%; the maximum value of friction reduction is 45.7%. The height of the barrel surface increased from 2.5 μm to 5.0 μm, the amplitude of the minimum film thickness decreased by 46.5% and the maximum friction increased by 57.1%.