太原科技大学
本科生毕业设计（说明书）
液压挖掘机液压系统设计
Hydraulic Excavator Hydraulic System of Design
学 院（系）： 机械工程学院 专 业： 机械设计制造及其自动化（液压） 学 生 姓 名： 简立瑞 学 号： 200812030134 指 导 教 师： 魏聪梅 评 阅 老 师： 完 成 日 期： 2012.6.8
太原科技大学 Taiyuan University of Science and Technology
目 录
I 摘要········································································
Abstract··································································· I 1 绪论 ...................................................................... 1
1.1 选题意义 ............................................................ 1
1.2 挖掘机及其液压技术概述 .............................................. 1 1.3 国内外研究现状 ...................................................... 2 1.4 挖掘机发展趋势 ...................................................... 3 2 挖掘机液压系统概述 ........................................................ 5
2.1 挖掘机液压系统的基本组成及其基本要求 ................................ 5
2.2 挖掘机液压系统的基本动作分析 ........................................ 6 2.3 挖掘机液压系统的基本回路分析 ........................................ 6
2.3.1 限压回路 ....................................................... 6 2.3.2 缓冲回路 ...................................................... 7 2.3.3 节流回路 ....................................................... 8 2.3.4 行走限速回路 ................................................... 9 2.3.5 合流回路 ..................................................... 11 2.3.6 闭锁回路 ..................................................... 11 2.3.7 再生回路 ...................................................... 12 3 整机参数 ................................................................. 13 3.1 尺寸参数的选择······················································13
4 工作装置的设计···························································14
4.1 动臂机构参数选择····················································14 4.2 斗杆机构参数选择····················································15 4.3 铲斗机构参数选择····················································16 4.4 挖掘范围····························································18 5 挖掘机液压系统设计 ....................................................... 19 5.1 挖掘机的功用和对液压系统的要求 ..................................... 19 5.2 挖掘机液压系统原理图 ............................................... 20 5.3 系统分析 ........................................................... 20 5.4 元件的选择及其元件的设计计算········································22 5.4.1泵的选择······················································22
5.4.2液压缸的设计及其计算··········································22 1 斗杆液压缸的设计·············································22 2 铲斗液压缸的设计·············································30 3 各液压缸的参数···············································34 5.4.3 回转马达的计算及选型·········································36 5.4.4 行走马达的选择···············································37 5.4.5 油箱容积计算·················································37 5.4.6 油管尺寸计算·················································37 5.4.7 管接头的选择·················································38 5.4.8 阀类元件的选择···············································38 6 热平衡验算·······························································39
7 结论 ..................................................................... 42 参考文献 ................................................................... 43
致谢 ....................................................................... 44
液压挖掘机液压系统的设计
摘要
单斗挖掘机是一种重要的工程机械，广泛应用于房屋建筑、筑路工程、水利建设、农林开发、港口建设、国防工事等的土石方施工和矿山采掘工业中，对减轻繁重的体力劳动、保证工程质量、加快建设速度、提高劳动生产率起着十分巨大的作用。随着国家经济建设的不断发展，单斗挖掘机的需求量将逐年大幅度增长，其在国民经济建设中的作用将越来越显著。
近年来，有关挖掘机液压系统方面的文献并不少见，但文献的内容大多针对某一专题进行研究，系统地论述现代液压挖掘机液压系统的论文却较少，因此研究和设计液压挖掘机液压系统具有重要的现实意义和理论意义。
本论文主要概述挖掘机液压技术的发展史及其目前在国内的外发展情况，简述了液压挖掘机发展趋势，本文对液压挖掘机的常用液压回路进行了简单阐述和分析，对课题要求设计的液压挖掘机液压系统进行了方案设计及分析，并通过进一步计算确定了需要的液压元件完成选型。运用AutoCAD绘制液压系统原理图、液压布置图。最后通过验算证明了本设计的可行性。
关键词：单斗挖掘机，液压系统，液压布置图。
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