本书除了介绍液压与气压传动的基本原理、基本概念，还介绍机床、工程机械等多个行业设备中液压系统常用的液压元件、典型液压系统等。全书共10 章，第1～2 章为基础知识，包括液压与气压传动的基本原理和基本概念，以及液压流体力学基础；第3～6 章介绍液压传动常用的液压元件、液压油和液压系统辅助元件；第7～8 章介绍液压基本回路和典型液压回路；第9 章介绍液压系统设计与计算，通过一个设计实例阐明一般液压系统的设计原则、方法和步骤；第10 章介绍气压传动，包括常用的气压传动元件（简称气动元件）、气压传动基本回路（简称气动基本回路）和气压传动系统（简称气动系统）实例。

第一作者姚林晓：主要从事工程机械润滑装置三维设计及流动仿真模拟方面的教学科研工作。主持并参与省厅级科研项目12项，横向课题8项，获奖10项，其中作为主持获奖4项，○1"基于辛几何学的大型柔性空间结构动力特性研究”○2"柔性多体智能结构滑模控制研究与工程应用” ○3"车辆集中润滑系统润滑脂流动仿真模拟及工程应用”这三项分别获河南省教育厅科技成果一等奖，○4"车辆集中润滑系统润滑脂流动仿真模拟及工程应用”获河南省科技进步二等奖；主编和副主编出版教材各1部，参编学术专著1部；发表论文12篇，其中三篇第一作者论文分获河南省优秀论文二等奖和三等奖，SCI、EI收录论文4篇。授权专利7项。从事教学工作20年来，主要担任了液压与气压传动、机械原理和机械设计基础课程的本科生教学任务和计算流体力学的研究生教学任务。

目 录
第1 章 绪论 ·················································································································.1
1.1 液压与气压传动基本原理、组成和图形符号 ·······························································.2
1.1.1 液压与气压传动基本原理 ·············································································.2
1.1.2 液压与气压传动系统的组成 ··········································································.4
1.1.3 液压传动图形符号 ······················································································.5
1.2 液压与气压传动的优缺点 ·······················································································.6
1.2.1 液压与气压传动的优点 ················································································.6
1.2.2 液压与气压传动的缺点 ················································································.6
1.3 液压与气压传动的应用与发展 ·················································································.7
1.3.1 液压与气压传动的应用 ················································································.7
1.3.2 液压与气压传动技术的发展 ··········································································.8
1.4 本书内容安排 ······································································································.8
本章小结 ···················································································································.9
思考与练习 ················································································································.9
第2 章 液压流体力学 ·································································································.10
2.1 液体的主要物理性质 ···························································································.10
2.1.1 密度 ······································································································.10
2.1.2 压缩性和膨胀性 ·······················································································.11
2.1.3 黏性 ······································································································.11
2.2 液体静力学 ·······································································································.13
2.2.1 液体所受的作用力 ····················································································.13
2.2.2 静止液体微分方程的推导 ···········································································.14
2.2.3 静止液体微分方程的应用 ···········································································.15
2.2.4 压力的表示方法及单位 ··············································································.17
2.3 流动液体的力学基本规律 ·····················································································.18
2.3.1 经典流体力学研究方法介绍 ········································································.18
2.3.2 流动液体力学的基本概念 ···········································································.19
2.3.3 流动液体的连续性方程 ··············································································.20
2.3.4 理想液体流动的微分方程 ···········································································.20
2.3.5 伯努利方程 ·····························································································.21
2.3.6 动量方程 ································································································.22
2.4 液体在流动中的能量损失 ·····················································································.24
2.4.1 流态实验和雷诺数 ····················································································.24
2.4.2 液体圆管流动中的沿程压力损失 ··································································.26
2.4.3 液体流动中的局部压力损失 ········································································.29
2.4.4 管道系统中的总压力损失和压力效率 ····························································.30
2.5 液体在小孔和缝隙中的流动 ··················································································.32
2.5.1 液体在小孔中的流动 ·················································································.32
2.5.2 液体在缝隙中的流动 ·················································································.34
2.6 液压卡紧问题 ····································································································.40
2.6.1 液压卡紧的概念 ·······················································································.40
2.6.2 液压卡紧现象的原因分析 ···········································································.40
2.6.3 解决液压卡紧现象的措施 ···········································································.41
2.7 液压冲击 ··········································································································.41
2.7.1 阀门突然关闭引起液压冲击的物理过程 ·························································.42
2.7.2 液压冲击力的计算 ····················································································.42
2.7.3 减轻液压冲击的措施 ·················································································.43
2.8 空穴现象与气蚀现象 ···························································································.43
2.8.1 空气分离压与饱和蒸汽压 ···········································································.43
2.8.2 空穴现象 ································································································.44
2.8.3 气蚀现象 ································································································.45
本章小结 ·················································································································.45
思考与练习 ··············································································································.45
第3 章 液压泵和液压马达 ··························································································.48
3.1 概述 ················································································································.49
3.1.1 工作原理 ································································································.49
3.1.2 液压泵与液压马达的分类 ···········································································.50
3.1.3 液压泵和液压马达的基本参数 ·····································································.51
3.2 齿轮泵 ·············································································································.54
3.2.1 工作原理 ································································································.54
3.2.2 流量计算和流量脉动 ·················································································.55
3.2.3 外啮合齿轮泵的结构特点和优缺点及提高齿轮泵压力的措施 ······························.56
3.2.4 齿轮液压马达 ··························································································.59
3.3 叶片泵 ·············································································································.61
3.3.1 单作用叶片泵 ··························································································.61
3.3.2 双作用叶片泵 ··························································································.63
3.3.3 叶片液压马达 ··························································································.65
3.4 轴向柱塞泵 ·······································································································.65
3.4.1 斜盘式轴向柱塞泵的工作原理 ·····································································.66
3.4.2 斜盘式轴向柱塞泵典型结构 ········································································.67
3.4.3 总功率变量泵 ··························································································.73
3.5 负载敏感泵 ·······································································································.74
3.5.1 负载敏感泵的节能工作原理 ········································································.75
3.5.2 负载敏感泵的应用 ····················································································.76
3.6 多作用内曲线低速大转矩液压马达 ·········································································.78
3.6.1 结构组成 ································································································.79
3.6.2 工作原理 ································································································.80
本章小结 ·················································································································.80
思考与练习 ··············································································································.81
第4 章 液压缸 ···········································································································.82
4.1 液压缸的分类和工作原理 ·····················································································.83
4.1.1 液压缸的分类 ··························································································.83
4.1.2 液压缸的工作原理 ····················································································.84
4.2 液压缸的典型结构 ······························································································.90
4.2.1 液压缸的结构组成 ····················································································.90
4.2.2 液压缸的主要零件及装置 ···········································································.91
4.3 液压缸的设计和计算 ···························································································.95
4.3.1 液压缸设计过程中应注意的问题 ··································································.95
4.3.2 液压缸的主要尺寸确定 ··············································································.96
4.3.3 液压缸的强度校核 ····················································································.97
4.3.4 液压缸的稳定性校核 ·················································································.98
4.3.5 缓冲计算 ································································································.99
4.3.6 拉杆计算 ································································································.99
本章小结 ················································································································.101
思考与练习 ·············································································································.101
第5 章 液压控制阀 ···································································································.103
5.1 概述 ···············································································································.104
5.1.1 按功用分类 ····························································································.104
5.1.2 按控制方式分类 ······················································································.104
5.1.3 按结构形式分类 ······················································································.105
5.1.4 按连接方式分类 ······················································································.105
5.2 压力控制阀 ······································································································.106
5.2.1 溢流阀 ··································································································.106
5.2.2 减压阀 ··································································································.114
5.2.3 顺序阀 ··································································································.116
5.2.4 平衡阀 ··································································································.117
5.2.5 专用平衡阀 ····························································································.118
5.2.6 压力继电器 ····························································································.119
5.3 流量控制阀 ······································································································.121
5.3.1 节流阀和单向节流阀 ················································································.122
5.3.2 调速阀 ··································································································.124
5.3.3 分流集流阀 ····························································································.126
5.3.4 单路稳流阀 ····························································································.128
5.4 方向控制阀 ······································································································.131
5.4.1 单向阀 ··································································································.131
5.4.2 换向阀 ··································································································.135
5.5 工程机械常用液压阀 ··························································································.142
5.5.1 多路换向阀 ····························································································.142
5.5.2 减压阀式先导控制阀 ················································································.145
5.6 新型液压阀 ······································································································.147
5.6.1 电液比例阀 ····························································································.147
5.6.2 数字阀 ··································································································.149
本章小结 ················································································································.152
思考与练习 ·············································································································.154
第6 章 液压油和液压系统辅助元件 ···········································································.156
6.1 液压油 ············································································································.157
6.1.1 液压系统对液压油的基本要求 ····································································.157
6.1.2 液压油的特性 ·························································································.157
6.1.3 液压油的选择和使用 ················································································.159
6.1.4 液压油的污染及其控制 ·············································································.160
6.2 蓄能器 ············································································································.162
6.2.1 蓄能器的作用和分类 ················································································.162
6.2.2 蓄能器容积计算 ······················································································.164
6.2.3 蓄能器的使用和安装 ················································································.166
6.3 滤油器 ············································································································.166
6.3.1 滤油器的分类 ·························································································.167
6.3.2 滤油器的选用和安装 ················································································.169
6.4 油箱和热交换器 ································································································.170
6.4.1 油箱 ·····································································································.170
6.4.2 热交换器 ·······························································································.172
6.5 其他辅助元件 ···································································································.175
6.5.1 密封件 ··································································································.175
6.5.2 管件 ·····································································································.178
6.5.3 压力表 ··································································································.181
本章小结 ················································································································.181
思考与练习 ·············································································································.181
第7 章 液压基本回路 ································································································.183
7.1 压力控制回路 ···································································································.184
7.1.1 调压回路 ·······························································································.184
7.1.2 减压回路 ·······························································································.186
7.1.3 增压回路 ·······························································································.187
7.1.4 卸荷回路 ·······························································································.188
7.1.5 保压回路 ·······························································································.190
7.1.6 缓冲补油回路 ·························································································.191
7.2 速度控制回路 ···································································································.194
7.2.1 调速回路 ·······························································································.194
7.2.2 平衡回路 ·······························································································.202
7.2.3 增速回路 ·······························································································.203
7.2.4 快慢速换接回路 ······················································································.204
7.3 方向控制回路 ···································································································.206
7.3.1 换向回路 ·······························································································.206
7.3.2 浮动回路 ·······························································································.207
7.3.3 锁紧回路 ·······························································································.209
7.4 多执行元件控制回路 ··························································································.211
7.4.1 顺序动作回路 ·························································································.212
7.4.2 同步回路 ·······························································································.215
7.4.3 多缸快慢速互不干扰回路 ··········································································.216
本章小结 ················································································································.218
思考与练习 ·············································································································.218
第8 章 典型液压系统 ································································································.222
8.1 组合机床动力滑台液压系统 ·················································································.223
8.1.1 YT 4543 型动力滑台液压系统的性能要求 ······················································.223
8.1.2 YT 4543 型动力滑台液压系统的工作原理 ······················································.224
8.1.3 YT 4543 型动力滑台液压系统的特点 ····························································.226
8.2 液压机液压系统 ································································································.226
8.2.1 YB 32-200 型液压机液压系统的性能要求 ······················································.226
8.2.2 YB 32-200 型液压机液压系统的工作原理 ······················································.227
8.2.3 YB 32-200 型液压机液压系统的特点 ····························································.230
8.3 汽车起重机液压系统 ··························································································.231
8.3.1 Q 2-8 型汽车起重机的液压系统性能要求 ······················································.231
8.3.2 Q 2-8 型汽车起重机液压系统的工作原理 ······················································.231
8.3.3 Q 2-8 型汽车起重机液压系统的特点 ····························································.234
8.4 塑料注射成形机液压系统 ····················································································.234
8.4.1 塑料注射成形机液压系统的性能要求 ···························································.236
8.4.2 塑料注射成形机液压系统的工作原理 ···························································.236
8.4.3 塑料注射成形机液压系统的特点 ·································································.238
8.5 挖掘机液压系统 ································································································.239
8.5.1 挖掘机液压系统的性能要求 ·······································································.239
8.5.2 挖掘机液压系统的工作原理 ·······································································.239
8.5.3 YW-60 型挖掘机液压系统的特点 ·································································.243
8.6 带钢张力电液伺服液压系统 ·················································································.244
8.6.1 带钢张力电液伺服液压系统的性能要求 ························································.244
8.6.2 带钢张力电液伺服液压系统的工作原理 ························································.244
8.6.3 带钢张力电液伺服液压系统的特点 ······························································.245
本章小结 ················································································································.245
思考与练习 ·············································································································.245
第9 章 液压系统设计与计算 ·····················································································.247
9.1 液压系统的一般设计流程 ····················································································.248
9.2 系统工况分析与负载匹配 ····················································································.248
9.2.1 负载分析与负载循环图 ·············································································.249
9.2.2 运动分析及运动循环图 ·············································································.252
9.2.3 负载匹配 ·······························································································.253
9.3 液压系统设计 ···································································································.254
9.3.1 确定系统主要参数 ···················································································.254
9.3.2 拟定液压系统工作原理图 ··········································································.258
9.3.3 液压元件的选型 ······················································································.260
9.3.4 液压系统性能验算 ···················································································.266
9.3.5 结构设计及技术文件编制 ··········································································.268
9.4 液压系统设计实例 ·····························································································.271
9.4.1 系统工况分析 ·························································································.271
9.4.2 主要参数的确定 ······················································································.272
9.4.3 拟定液压系统工作原理图 ··········································································.274
9.4.4 液压元件的选择 ······················································································.277
9.4.5 液压系统的性能验算 ················································································.279
9.5 液压系统动态特性分析 ·······················································································.279
9.5.1 液压系统动态特性分析的作用 ····································································.279
9.5.2 液压系统动态特性分析的内容和方法 ···························································.281
9.5.3 系统数学模型 ·························································································.285
9.5.4 动态特性分析实例 ···················································································.285
本章小结 ················································································································.293
思考与练习 ·············································································································.293
第10 章 气压传动 ·····································································································.294
10.1 气压传动概述 ·································································································.295
10.1.1 气压传动的特点 ·····················································································.295
10.1.2 气压传动系统的组成 ···············································································.295
10.2 气动元件 ·······································································································.296
10.2.1 气源装置 ······························································································.297
10.2.2 辅助元件 ······························································································.300
10.2.3 气动执行元件 ························································································.301
10.2.4 气动控制元件 ························································································.303
10.2.5 气动逻辑元件 ························································································.309
10.3 气动基本回路 ·································································································.313
10.3.1 方向控制回路 ························································································.313
10.3.2 压力控制回路 ························································································.313
10.3.3 速度控制回路 ························································································.314
10.3.4 其他回路 ······························································································.317
10.4 气动系统应用实例 ···························································································.319
10.4.1 气液动力滑台的气动系统 ·········································································.320
10.4.2 射芯机气动系统 ·····················································································.321
本章小结 ················································································································.323
思考与练习 ·············································································································.323
参考文献 ·····················································································································.324
附录 GBT 786.1—2009《流体传动系统及元件图形符号和回路图》（节选） ···············.326