【作者】 朱巨才；

【导师】 符炜；

【作者基本信息】 湘潭大学 ， 机械设计及理论， 2004， 硕士

【摘要】 本文首先对含运动副间隙机构的动力学研究背景与现状等进行了综述,详细分析介绍了现有的含间隙机构的动力学建模与求解方法。然后,重点研究了含间隙机构的无质量杆.弹簧阻尼组合模型(massless-link/spring-damper model,简称为 MISD 模型),提出了一种新的求解该模型方程的近似解法,并将其应用于实际机构的动力学分析与设计中。作者以 MISD 模型为基础对含间隙四杆机构进行分析,建立了该模型的动力学运动微分方程组;提出了一种新的基于解析法的求解MISD模型非线性动力学运动微分方程组的近似方法,并将其与用变步长四阶龙格库塔方法对二状态模型进行数值积分求解的结果进行了比较,发现二者在整体上吻合得很好。该方法使解决问题的难度大为降低且具有较高的精度,因此也可作为一种新的预测含间隙机构运动副元素是否分离与碰撞的有效方法。在此基础上,作者采用 MLSD 模型对一新型双连杆双曲轴柴油机的主体机构进行了考虑运动副间隙的建模分析,得到了该机构的动力学非线性运动微分方程组。同时,运用上述近似求解方法对这些非线性运动微分方程组进行分析求解,并对所分析的双连杆双曲轴机构的重要参数β进行了优化。该近似解法简单、实用,避免了用数值计算求解的困难,对新型双连杆双曲轴柴油机的深入研究和设计实践具有参考价值。更多还原

【Abstract】 The research background and actuality in the mechanism with cJearance joints are summarized,and existing dynamic modelsand solutions are analyzed.Then,a combined massless.1ink/spring.damper(MLSD)model is studied and a new approximatemethod of solving MLSD model equations is put forword.It isapplied in dynamic analysis and design of the mechanism withclearance ioints. Dynamic motion differential equations of the MLSD mOdel are obtained based on theoretical analysis to a four-barmechanism with clearance and a new approximate method ofsolving MLSD model equations is founded.The computationalresult of approximate method corresponds with thecomputational result of Runge.kutta method in whole.Theapproximate method reduces the difficulty Of solution and hasbetter precision.So it is a new effective memOd Of predictingcontact loss of pairing elements. The MLSD model is used to study the double connectifig-roddouble-crankshalf mechanism with clearance joints which ismain mechanism of a new diesel engine,and the non-1inear motiOndifferential equations of the mechanism are obtained.By usingthe approximate method,the equations are solved and theparameterβof mechanism IS optimized.The method is simple andconvenient and it does not need numerical computation.Thereis referenced value tO further study and design of the newdouble connecting-rOd and double—crankshalf diesel engine.更多还原