增压直喷汽油机连杆大头轴承润滑特性研究

某增压直喷汽油发动机是在某增压发动机的基础上开发得到的，为满足连杆工作过程中的可靠性要求，需要对增压发动机的连杆工字梁结构进行加强，由此使连杆质量增加了12g。应用多体动力学方法，利用连杆轴承弹性流体动力学（EHD）计算分析连杆增加质量后对连杆大头轴承润滑特性的影响。计算结果表明，增加质量后，连杆大头轴承总摩擦功率损失增加，峰值总压力也随之增加，最高增幅为9．7％，机油温升也提高，最小油膜厚度变化较小。

Study on Lubricating Characteristics of Connecting-Rod Big-End Bearing in a Turbo-charged Direct Injection Gasoline Engine

A turbo-charged gasoline direct injection （TGD]） engine was developed based on a preceding turbocharged engine. To satisfy the reliability requirements during the connectlng-rod operation, the structure of connecting rod needed to be reinforced by increasing ＂ I ＂ shape section size, which led to a 12g mass increase accordingly. The effect of connecting-rod mass increase on its big-end bearing lubricating characteristics was analyzed by applying multi-body dynamic method and connecting-rod bearing EHD （elasto-hydro dynamics） calculation. The result indicated, after the connecting--rod mass increased ,the total friction power loss and oil temperature increased, and total peak pressure increased by 9.7%, and the change in minimum oil film thickness was less.