【作者】 王刚志；

【导师】 舒歌群；

【作者基本信息】 天津大学 ， 动力机械及工程， 2007， 博士

【摘要】 内燃机向小体积、高功率密度、高转速和大负荷方向发展。本文以多缸内燃机主轴承为研究对象,以系统论原理为指导,考虑表面形貌效应、弹性变形效应和热效应对其进行了热弹性流体动力润滑分析。同时,对多缸内燃机主轴承的润滑状况进行了试验研究。推导了光滑表面简化假设下,适用于内燃机主轴承的狭义Reynolds方程;推导了适用于内燃机主轴承的摩擦功耗、润滑油流量和等效温度等的计算公式。详细研究了内燃机主轴承载荷计算的简支梁法和连续梁法,分别用两种算法计算了某四缸柴油机的五个主轴承的载荷。计算结果表明,连续梁法比简支梁计算法计算精度高。主轴承的润滑计算应以连续梁轴承载荷为依据。详细研究了内燃机主轴承的热弹性流体动力润滑(TEHD)理论。引入了含机油填充率的扩展Reynolds方程,给出了弹性变形方程、油膜能量方程、热传导方程和载荷平衡方程以及相应的边界条件。以某四缸柴油机为例,对其各档主轴承的润滑状况进行了计算分析,同时将TEHD计算方法同EHD和HD算法进行比较,得到了一些有价值的结论。较为全面地研究了内燃机主轴承润滑性能的影响因素。考虑的主要影响因素有油槽、相对间隙、宽径比、贫油、润滑油类型以及润滑油密度,得出了一些有价值的结论。以系统论原理为指导,对内燃机主轴承进行摩擦学设计。以4100QB柴油机为例对其第三号主轴承进行了摩擦学优化设计,提出了两套设计方案。两套方案都不同程度地增大了该主轴承的油膜厚度,降低了摩擦功耗。对多缸内燃机主轴承的润滑状况进行了试验研究。采用两个非接触式电涡流传感器测量油膜厚度并合成轴心轨迹,同时还测量了不同工况下的进油温度、压力、油膜温度等。结果表明,用TEHD计算方法算出的油膜厚度同试验结果相近。更多还原

【Abstract】 Internal-combustion engine develops face small volume, high power density, high rotation rate and heavy load. The paper takes main journal bearings of Multicylinder internal-combustion engine as objects to research. Under Systems Principles, being considered with surface topography effect, with elastic-deformation effect and thermal effect, thermoelastohydrodynamic(short for TEHD) analysis of the main bearings have been done. Meanwhile, lubrication conditions of a Multicylinder internal-combustion engine have been tested.Reynolds, friction power loss, lubricant flux and calefaction equation which are suitable for main bearings of internal-combustion engine have been inferred on the basis of surface lubricity.Loads of five main journal bearings are respectively calculated with determinate and indeterminate load computing methods after the methods are researched carefully. It makes clear that indeterminate load computing method is precise than determinate method. Lubrication calculation of main journal bearings should be based on the indeterminate load computing method.TEHD theory for main journal bearing has been discussed in detail. Extended Reynolds equation contained with lubricant fill ratio is introduced. Equations of solid elastic deformation, oil film enery, thermal conduction and loading are given as well as their boundary conditions. Being taken a diesel engine as as example, lubrication performances of five main journal bearings of it are calculated and analysed. In the dissertation, some valuable conclusions are illuminated after that the calculation method of TEHD is compared with that of EHD and HD.Various influence effects of main journal bearings of ICE are considered roundly. They are oil groove, relative axial clearance, ratio of width and diameter, poor oil, types of lubricant and density of lubricant. Some valuable conclusions are illuminated.On the guidance of Systems Principles, tribological design of main journal bearings of ICE is put forward. Two tribological design schemes of NO 3 main bearing of 4100QB diesel engine are given. Both of them enhance minimum oil film thickness and reduce friction power loss.Lubrication performances of main journal bearings of multicylinder ICE are tested in state key laboratory of engines. Oil film thicknesses which are measured by two non contact electric vortex sensors are synthesized to form center orbital path. Inlet oil temperature, oil film temperature and oil pressure etc on different operation condition are also synchronously measured. It can be found that the minimum oil film thickness calculated by TEHD method is close to that of measurement.更多还原