摘要曲轴是发动机中最重要的机件之一，其性能直接影响着发动机的可靠性和寿命。它的作用是把活塞的往复直线运动变成旋转运动，将作用在活塞的气体压力变成扭矩，用来驱动工作机械和柴油发动机各辅助系统进行工作。曲轴在工作时承受着不断变化的压力、惯性力和它们的力矩作用。因此，在设计曲轴时，必须正确选择曲轴的尺寸参数、结构形式、材料与工艺，使其具有较高的疲劳强度，较大的刚度以及良好的耐磨性以及合理的经济性。

本次设计的主要任务是375柴油机曲轴的结构设计、三维建模及其加工工艺分析。首先，根据柴油机的性能指标对柴油机曲轴的材料以及主要性能参数进行选择，再参照375柴油机的曲轴结构进行结构设计以及三维建模。其次，根据已取定的曲轴的各尺寸参数，选出易发生应力集中现象的部位进行强度校核。最后，查阅有关资料结合曲轴结构特性编制曲轴加工工艺规程。49805

毕业论文关键词：375柴油机、曲轴、结构设计、三维建模、加工工艺  

 Abstract The crankshaft of the engine is one of the most important parts, its performance directly affects the reliability and life of the engine. Its action is change the to and fro straight-line motion of the piston into rotary motion,and change the gas pressure on the piston into torque, that is used to drive executive body and accessory system of the diesel engine. Crankshaft is withstanding the changing pressure, inertia force and the torque. Therefore, in the design of the crankshaft, the dimensions, structure, materials and processes of crankshaft must be selected properly, so that it has a high fatigue strength, a large stiffness, a good wear resistance and a reasonable economy. 

The main task of this design is the structural design, three-dimensional modeling, and process analysis of the 375 diesel engine’s  crankshaft. First, according to the performance indicators of diesel engine select the materials and the main performance parameters of diesel engine’s crankshaft, then design the structure and build 3D models of crankshaft by referring to the structure of 375 diesel engine’s crankshaft. Secondly, according to the given size parameters of crankshaft to pick out the parts easing to produce the phenomenon of stress concentration and check its strength. Finally, access to relevant information and prepare the crankshaft processing technology combining with the structural properties of the crankshaft .

Key words: 375 diesel engine; crankshaft; structural design; 

three-dimensional modeling; processing technology 

目  录

第一章 绪论 1

1.1 选题的目的和意义 1

1.2 国内外研究现状及存在的问题 2

1.3 本文的主要内容 3

第二章 曲轴的结构设计 4

2.1 375柴油机主要技术参数 4

2.2 曲轴概述 4

2.3 曲轴的结构型式及其选择 5

2.3.1 曲轴的结构形式 5

2.3.2 曲轴的材料 6

2.4 曲轴的基本尺寸 6

2.4.1 主轴颈和曲柄销 6

2.4.2 曲柄臂 7

2.4.3 曲轴圆角 8

2.4.4 润滑油道 8

2.4.5 曲轴平衡块