目

录

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........................................................................................4

2.1 挖掘机液压系统的基本组成及其基本要求.........................................................................................4
2.2 挖掘机液压系统的基本动作分析.........................................................................................................5
2.3 挖掘机液压系统的基本回路分析.........................................................................................................5

2.3.1 限压回路........................................................................................................................................5
2.3.2  缓冲回路.......................................................................................................................................6
2.3.3 节流回路........................................................................................................................................7
2.3.4 行走限速回路...............................................................................................................................8
2.3.5  合流回路.....................................................................................................................................10
2.3.6  闭锁回路.....................................................................................................................................11
2.3.7 再生回路......................................................................................................................................11

3 挖掘机液压系统设计......................................................................................12

3.1 挖掘机的功用和对液压系统的要求...................................................................................................12
3.2 挖掘机液压系统分析............................................................................................................................12

3.2.1 挖掘机的液压系统原理图.........................................................................................................12
3.2.2 系统工作循环分析.....................................................................................................................14
3.2.3 主要液压元件在系统中的作用................................................................................................15
3.2.4 液压系统中几种低压回路的作用............................................................................................15

3.3 液压元件的选用....................................................................................................................................16

3.3.2 液压阀的选用.............................................................................................................................16
3.3.4 辅助元件的选用.........................................................................................................................16

4 参数计算及选择.............................................................................................17

4.1 计算所需要的泵的流量........................................................................................................................17
4.2 回转台启动力矩和制动力矩................................................................................................................19
4.2 泵的选择.................................................................................................................................................25
4.3 油箱容积计算.........................................................................................................................................25
4.4 油管尺寸计算.........................................................................................................................................26
4.5 热平衡验算.............................................................................................................................................28

5 结论.............................................................................................................29

参考文献..........................................................................................................30

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