编号：
本 科 毕 业 设 计
题 目：学 院：专 业：年 级：姓 名：指导教师：完成日期：
挖掘机液压系统的分析与设计 机械工程学院 机械设计制造及其自动化
级机制 班 ２０１２ 年6月1日
挖掘机液压系统的分析与设计
摘要
液压挖掘机是工程机械的一个重要品种，是一种广泛用于建筑、铁路、公路、水利、采矿等建设工程的土方机械。液压挖掘机利用液压元件（液压泵、液压马达、液压缸等）带动各种构件动作，具有许多优点，于是它对液压系统的设计提出了很高的要求，其液压系统也是工程机械液压系统中最为复杂的。因此，对挖掘机液压系统的分析设计对推动我国挖掘机发展具有十分重要的意义。
在搜集了国内外挖掘机液压系统相关资料的基础上，了解了挖掘机液压系统的发展历史，并对挖掘机液压系统的技术发展动态进行了分析总结。本次毕业设计课题是液压挖掘机。挖掘机由多个系统组成，包括液压系统，传动系统，操纵系统，工作装置，底架，转台，油箱，发动机安装等。本人的设计主要致力于分析和设计中型液压挖掘机液压系统的液压元件。以液压元件和液压回路为主。
关键词：挖掘机；液压系统；液压泵
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Excavator Hydraulic System Analysis and Design
Abstract
Hydraulic excavator,one of important engineering machine, is a widely used in construction, railway, highway, water conservancy, mining, etc construction projects of earthwork machinery. Hydraulic excavator using hydraulic components (hydraulic pump hydraulic motor hydraulic cylinder, etc) drive the various components action, has many advantages and puts forward high demand for hydraulic system design, and the hydraulic systems of engineering machinery in hydraulic system is complex. Therefore, the excavator hydraulic system analysis and design has the extremely vital significance for impelling our country excavator development.
Based in the materials of the domestic and foreign excavator hydraulic system,we learn about the excavator hydraulic system development history and summerize the dynamic development of excavator hydraulic system technology.The graduation design task is hydraulic excavator made by multiple system components, including hydraulic system, transmission system, control systems, work device, chassis, turntable, tank, engine installation, etc. The design is mainly devoted to the analysis and design of medium-sized hydraulic excavator hydraulic system hydraulic components,especially hydraulic components and hydraulic circuit.
Keywords :Excavator;Hydraulic System;Hydraulic Pump
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目录
1. 概论 ............................................................................................................................................. 1
1.1 挖掘机的简介 ................................................................................................................... 1 1.2 液压挖掘机的发展概况 ................................................................................................... 3
1.2.1 国外液压挖掘机研究状况及发展趋势 ............................................................... 5 1.2.2 国内液压挖掘机的发展概况 ............................................................................... 7 1.3 本论文研究内容 ............................................................................................................... 8 1.4 内容安排 ........................................................................................................................... 9 2．挖掘机液压系统的计算 ............................................................................................................. 9
2.1 设定液压挖掘机的基本参数 ........................................................................................... 9
2.1.1 挖掘机液压系统的简介 ....................................................................................... 9 2.1.2 YW-160型单斗液压挖掘机液压系统 ................................................................ 10 2.2 液压挖掘机工作装置油缸作用力的确定 ..................................................................... 12
2.2.1 动臂油缸作用力分析 ......................................................................................... 12 2.2.2 铲斗油缸工作受力分析 ..................................................................................... 13 2.2.3 斗杆油缸作用力分析 ......................................................................................... 15 2.3 液压元件的计算 ............................................................................................................. 16
2.3.1 液压缸内径 ......................................................................................................... 16 2.3.2 缸筒壁厚 ............................................................................................................. 16 2.3.3 缸筒壁厚验算 ..................................................................................................... 17 2.3.4 活塞杆计算 ......................................................................................................... 17 2.3.5 活塞杆强度计算 ................................................................................................. 17 2.3.6 确定液压系统的工作压力 ................................................................................. 17 2.3.7 确定液压缸的主要参数和工作压力 ................................................................. 18 2.3.8 确定液压马达的排量和工作压力 ..................................................................... 18 2.3.9 计算液压缸与液压马达的流量 ......................................................................... 19
3. 液压元件的选择 ....................................................................................................................... 19
3.1 液压缸的选择 ................................................................................................................. 19 3.2 液压泵的选择 ................................................................................................................. 19 3.3 液压马达的选择 ............................................................................................................. 20 3.4 发动机的选择 ................................................................................................................. 20 4．液压系统回路的设计 ............................................................................................................... 21
4.1 液压缸控制回路 ............................................................................................................. 21 4.2 液压马达控制回路 ......................................................................................................... 21 4.3 计算系统所需的最大流量 ............................................................................................. 22 4.4 压力损失的计算 ............................................................................................................. 23 4.5 拟定液压源控制回路 ..................................................................................................... 23 5. 液压系统性能验算 ................................................................................................................... 24
5.1 液压系统功率损失 ......................................................................................................... 24 5.2 液压油油温过高的原因及预防措施 ............................................................................. 25 6．结论和展望 ............................................................................................................................... 28
6.1 结论 ................................................................................................................................. 28 6.2 展望 ................................................................................................................................. 28
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