设计简介
摘 要
本次设计题目为小型农田起重机，目的是设计一个适合农田使用的小型起重机。首先确定小型农田起重机的总体设计方案，查找相关书籍、资料，再根据最大起重量0.35t的要求进行移动底盘，回转机构、变幅机构、起升机构的具体设计。本次小型农田起重机的底盘采用履带式底盘，驱动轴在底盘前部；回转机构采用单行星齿轮系，动力从太阳轮输入，外齿圈输出，带动上车底盘回转；变幅机构利用四杆机构的原理，使用液压缸推动前臂做起、落，实现起重机的变幅；起升机构采用卷扬机收缩钢丝绳带动吊钩起升重物，为了防止干涉现象的产生，起升机构涉及到定滑轮组的选择。其次，利用材料力学所学的知识进行关键部件的强度、挠度计算；以及利用所给定的尺寸、零件的质量进行防倾覆计算，计算结果与规定参数进行比较，对尺寸进行调整，然后确定小型农田起重机的外形尺寸，以及部分零件的尺寸、加工精度、公差等级等等。最后，利用三维软件进行三维图的绘制，在生成2D工程图，在2D图纸中进行尺寸的标注；选择几个主要零件进行零件图的绘制。
关键词：回转机构；变幅机构；起升机构；强度校核
本次设计题目为小型农田起重机，目的是设计一个适合农田使用的小型起重机。首先确定小型农田起重机的总体设计方案，查找相关书籍、资料，再根据最大起重量0.35t的要求进行移动底盘，回转机构、变幅机构、起升机构的具体设计。本次小型农田起重机的底盘采用履带式底盘，驱动轴在底盘前部；回转机构采用单行星齿轮系，动力从太阳轮输入，外齿圈输出，带动上车底盘回转；变幅机构利用四杆机构的原理，使用液压缸推动前臂做起、落，实现起重机的变幅；起升机构采用卷扬机收缩钢丝绳带动吊钩起升重物，为了防止干涉现象的产生，起升机构涉及到定滑轮组的选择。其次，利用材料力学所学的知识进行关键部件的强度、挠度计算；以及利用所给定的尺寸、零件的质量进行防倾覆计算，计算结果与规定参数进行比较，对尺寸进行调整，然后确定小型农田起重机的外形尺寸，以及部分零件的尺寸、加工精度、公差等级等等。最后，利用三维软件进行三维图的绘制，在生成2D工程图，在2D图纸中进行尺寸的标注；选择几个主要零件进行零件图的绘制。
关键词：回转机构；变幅机构；起升机构；强度校核
ABSTRACT
This graduation design topic is small farmland crane, the purpose is to design a small crane suitable for farmland use. First, the general design scheme of small farm crane is determined, and the relevant books and materials are searched, and then the specific design of moving chassis, rotating mechanism, amplitude changing mechanism and lifting mechanism is carried out according to the requirement of the maximum lifting weight of 0.35 t. The chassis of this small farm crane adopts crawler chassis, driving shaft is in the front part of the chassis; the rotary mechanism adopts single planetary gear system, the power is input from the sun wheel, the output of the outer gear ring, drives the chassis to turn on the car; Using the principle of four-bar mechanism, the luffing mechanism uses the hydraulic cylinder to push the forearm to start and fall, to realize the shift of the crane, and the lifting mechanism uses the winder to shrink the wire rope to drive the hoist to lift the heavy object in order to prevent the interference. The hoisting mechanism relates to the selection of fixed pulley sets. Secondly, using the knowledge of material mechanics to calculate the strength and deflection of the key parts, and to calculate the anti-capsizing by using the given dimensions and the quality of the parts, the calculated results are compared with the prescribed parameters, and the dimensions are adjusted. Then determine the size of the small farm crane shape, as well as some parts of the size, processing accuracy, tolerance grade and so on. Finally, 3D software is used to draw 3D drawings, 2D engineering drawings are generated, dimensions are marked in 2D drawings, and several main parts are selected to draw part drawings.
Keywords: Rotary mechanism; Amplitude change mechanism; Hoisting mechanism; Strength checking
This graduation design topic is small farmland crane, the purpose is to design a small crane suitable for farmland use. First, the general design scheme of small farm crane is determined, and the relevant books and materials are searched, and then the specific design of moving chassis, rotating mechanism, amplitude changing mechanism and lifting mechanism is carried out according to the requirement of the maximum lifting weight of 0.35 t. The chassis of this small farm crane adopts crawler chassis, driving shaft is in the front part of the chassis; the rotary mechanism adopts single planetary gear system, the power is input from the sun wheel, the output of the outer gear ring, drives the chassis to turn on the car; Using the principle of four-bar mechanism, the luffing mechanism uses the hydraulic cylinder to push the forearm to start and fall, to realize the shift of the crane, and the lifting mechanism uses the winder to shrink the wire rope to drive the hoist to lift the heavy object in order to prevent the interference. The hoisting mechanism relates to the selection of fixed pulley sets. Secondly, using the knowledge of material mechanics to calculate the strength and deflection of the key parts, and to calculate the anti-capsizing by using the given dimensions and the quality of the parts, the calculated results are compared with the prescribed parameters, and the dimensions are adjusted. Then determine the size of the small farm crane shape, as well as some parts of the size, processing accuracy, tolerance grade and so on. Finally, 3D software is used to draw 3D drawings, 2D engineering drawings are generated, dimensions are marked in 2D drawings, and several main parts are selected to draw part drawings.
Keywords: Rotary mechanism; Amplitude change mechanism; Hoisting mechanism; Strength checking
目 录
摘 要 I
ABSTRACT II
1 绪论 1
1.1 概述 1
1.2 课题的研究背景及主要任务 1
1.3 方案一二三比较 2
2 小型农田起重机主要目标设计参数的确定 3
3 移动底盘的参数设计 4
3.1 移动底盘输出轴设计 4
3.2 根据弯扭合成应力校核轴的强度 6
3.3 校核轴的疲劳强度 6
3.4 输出轴滚动轴承计算 8
3.5 输出轴键的计算 9
3.6 选择轴承的润滑与密封方式 9
4 回转机构的参数设计 11
4.1 根据齿面接触强度进行设计 11
4.2 按齿根弯曲疲劳强度进行验算是否符合要求 13
4.3 几何尺寸计算 15
5 变幅机构的参数设计 16
5.1 前臂 16
5.2 立柱 18
5.3 液压缸 19
5.4 前一臂的结构分析 23
5.5 下车与上车连接处支承立柱强度校核 27
5.6 液压稳定性强度校核 28
5.7 起重机稳定性计算 29
6 移动底盘的参数设计 32
6.1 吊钩机构的参数 32
6.2 其他重要参数 33
7 结论 34
参 考 文 献 36
致 谢 43
