内燃机主轴承变形特性及影响规律研究

发布时间：2018-01-16 21:36

本文关键词：内燃机主轴承变形特性及影响规律研究　出处：《北京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：曲轴作为往复式压缩机的关键核心部件，曲轴在机组运转过程中承受着随时间周期性变化的交变载荷，正是这种交变载荷的作用使得曲轴和主轴承受到不同程度的变形，不仅影响着自身的使用寿命，而且关系到发动机的安全性和稳定性，对其他零部件的使用寿命和性能也存在很大的负面影响。因此对曲轴与主轴承结构之间的动力学特性特别是彼此之间变形的协调性分析已成为内燃机可靠性工程中的重要课题。本文主要围绕以下三个方面进行研究： ⑴如何表达和评价曲轴与主轴承的变形根据形位误差理论对圆类零件变形的评价指标进行了研究，包括描述主轴承横截面变形的失圆度；描述多个主轴承整体性变形情况的同轴度、圆跳动和圆柱度；以及主轴承与外面零部件（曲轴）之间变形的协调性，并且将这些评价指标的数学定义实现为算法代码。 ⑵曲轴与主轴承的动力学特性及影响规律研究以某12V机型柴油机为研究对象进行曲轴-主轴承结构动力学仿真分析，分析中主要运用AVL-EXCITE动力学和有限元相结合的方法，得到曲轴系的扭转振动特性，并通过实验对仿真模型进行了验证。采用轴承间隙和轴颈倾斜角度等参数对曲轴-主轴承之间的协调变形进行了研究，归纳了不同转速、轴承径向间隙、不同载荷及油压下曲轴-主轴承协调变形影响规律。 ⑶关键参数对单个及整体主轴承变形影响分析建立了曲轴、机体有限元模型，，研究主轴承在预紧工况、过盈工况、润滑油膜载荷工况下的主轴承刚度分析，并归纳不同参数对主轴承截面失圆度和多个主轴承整体协调变形的影响规律。为内燃机主轴承变形分析提供指导依据。
[Abstract]:Crankshaft as the key component of reciprocating compressor, crankshaft in the operation process of the unit to withstand periodic changes with time alternating load. It is this kind of alternating load that causes the crankshaft and the main bearing to be deformed to varying degrees, which not only affects their service life, but also relates to the safety and stability of the engine. Therefore, the coordination analysis of dynamic characteristics between crankshaft and main bearing structure, especially the deformation between each other, has become the reliability engineering of internal combustion engine. This paper focuses on the following three aspects:. 1. How to express and evaluate the deformation of crankshaft and main bearing According to the theory of shape and position error, the evaluation index of circular parts deformation is studied, including describing the misroundness of cross section deformation of main bearing. Describes the coaxiality, roundness and cylindricity of the integral deformation of multiple main bearings; And the compatibility of deformation between the main bearing and the outside parts (crankshaft), and the mathematical definition of these evaluation indexes is realized as the algorithm code. Study on dynamic characteristics and influence law of crankshaft and main bearing Taking a 12V diesel engine as the research object, the dynamic simulation of crankshaft-main bearing structure is carried out. The method of combining AVL-EXCITE dynamics with finite element method is mainly used in the analysis. The torsional vibration characteristics of crankshaft system are obtained and the simulation model is verified by experiments. The coordinated deformation between crankshaft and main bearing is studied by using the parameters such as bearing clearance and journal inclination angle. The effects of different rotational speed, radial clearance, different load and oil pressure on the coordinated deformation of crankshaft and main bearing are summarized. Analysis of influence of key parameters on deformation of single and integral main bearing The finite element model of crankshaft and block is established to study the stiffness analysis of main bearing under preload condition, interference mode and lubricating oil film load condition. The influence of different parameters on the misroundness of the main bearing section and the coordinated deformation of multiple main bearings is summarized, which provides a guide for the analysis of the deformation of the main bearing of the internal combustion engine.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK428

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