本教材的内容以液压传动为主，气压传动为辅，主要介绍液压与气压传动的基本概念及基本理论知识，主要包括液压与气动元件、液压与气动基本回路、液压与气动典型回路、液压与气动系统的安装、调试及维护等。对于重点要培养的能力及学习的知识点，均编写了相应的实践教学任务，旨在强化学生的实际操作能力和团队协作意识。

苏冬云，女，南通职业大学副教授，模具协会会员，主要研究方向和著作方向是液压与气压传动。近5年来，主持省级教研课题《液压传动和气动技术课程的SPOC建设研究》一项，已结题；主持市级科研课题2项，已结题；主持横向课题2项，已结题；参加省级科研课题2项，已结题。授权发明专利2项，授权实用新型专利5项。发表论文4篇，其中发表SCI论文1篇、EI检索论文2篇。并分别于2011年和2016年出版教材《液压与气动技术》。

项目一 气压传动概述·····················································································.1
任务一 认识气动系统···············································································.1
一、气动系统的工作原理······································································.1
二、气动系统的组成············································································.3
任务二 气动系统的特点············································································.3
一、气压传动的优点············································································.4
二、气压传动的缺点············································································.4
任务三 气压与液压传动的发展及应用 ·························································.4
练习题····································································································.5
项目二 气压传动基础知识···············································································.6
任务一 空气的物理性质············································································.6
一、空气的组成··················································································.6
二、空气的压力··················································································.6
三、空气的密度··················································································.7
四、空气的黏性··················································································.7
五、空气的湿度··················································································.8
六、空气的可压缩性和膨胀性 ·······························································.9
任务二 气体的状态方程············································································.9
一、理想气体的状态方程······································································.9
二、气体状态变化方程·······································································.10
练习题··································································································.11
项目三 气源装置及辅助元件··········································································.12
任务一 气源装置···················································································.12
一、气源装置的作用和工作原理 ··························································.12
二、空气压缩机················································································.13
三、气源净化装置·············································································.14
任务二 辅助元件···················································································.17
一、油雾器······················································································.17
二、消声器······················································································.18
三、气-液转换器 ··············································································.19
练习题··································································································.20
项目四 气动执行元件···················································································.21
任务一 气缸·························································································.21
一、气缸的分类················································································.21
二、几种常见的气缸··········································································.22
任务二 气压马达···················································································.25
一、气压马达的工作原理····································································.25
二、气压马达的选用原则及使用要求 ····················································.26
练习题··································································································.26
项目五 气动控制元件···················································································.27
任务一 方向控制阀················································································.27
任务二 压力控制阀················································································.33
任务三 流量控制阀················································································.36
练习题··································································································.37
项目六 气动基本回路···················································································.38
任务一 方向控制回路·············································································.38
一、单作用气缸换向回路····································································.38
二、双作用气缸换向回路····································································.38
任务二 压力控制回路·············································································.39
一、一次压力控制回路·······································································.40
二、二次压力控制回路·······································································.40
任务三 速度控制回路·············································································.41
一、单作用气缸速度控制回路 ·····························································.41
二、双作用气缸速度控制回路 ·····························································.42
三、速度换接回路·············································································.43
四、缓冲回路···················································································.43
任务四 其他常用气动基本回路 ································································.44
一、安全保护回路·············································································.44
二、顺序动作回路·············································································.46
练习题··································································································.48
项目七 典型气动系统···················································································.49
任务一 气动机械手气动系统····································································.49
任务二 数控加工中心气动换刀系统 ··························································.51
练习题··································································································.53
项目八 气动系统的安装调试与维护 ································································.54
任务一 气动系统的安装与调试 ································································.54
一、气动系统的安装··········································································.54
二、气动系统的调试··········································································.55
三、气动系统的使用及维护 ································································.55
任务二 气动系统的故障分析与排除 ··························································.57
练习题··································································································.60
项目九 液压传动概述···················································································.61
任务一 认识液压系统·············································································.61
一、液压系统的工作原理····································································.61
二、液压系统的图形符号表示 ·····························································.63
任务二 液压系统的组成及液压传动的特点 ·················································.64
一、液压系统的组成··········································································.64
二、液压传动的特点··········································································.65
练习题··································································································.66
项目十 液压传动的流体力学基础····································································.67
任务一 液压传动的工作介质····································································.67
一、液压油的主要物理性质 ································································.67
二、液压油的分类和选用····································································.68
三、液压油的污染与控制····································································.70
任务二 液体静力学基本知识····································································.71
一、液体的压力················································································.71
二、液体静力学基本方程····································································.71
三、压力的传递················································································.72
四、压力的表示方法··········································································.72
五、静止液体对固体壁面的作用力 ·······················································.72
任务三 液体动力学基本知识····································································.73
一、基本概念···················································································.73
二、流量连续性方程··········································································.75
任务四 液体流动时的压力损失 ································································.75
一、沿程压力损失·············································································.76
二、局部压力损失·············································································.76
三、管路系统的总压力损失 ································································.76
任务五 液体流经小孔及缝隙的特性 ··························································.77
一、液体流经小孔的特性····································································.77
二、液体流经缝隙的特性····································································.78
任务六 液压冲击和空穴现象····································································.79
一、液压冲击···················································································.79
二、空穴现象···················································································.80
练习题··································································································.81
项目十一 液压动力元件················································································.83
任务一 液压泵概述················································································.83
一、液压泵的工作原理及种类 ·····························································.83
二、液压泵的主要性能参数 ································································.84
任务二 齿轮泵······················································································.87
一、外啮合齿轮泵的结构组成及工作原理 ··············································.87
二、外啮合齿轮泵的结构特点 ·····························································.87
任务三 叶片泵······················································································.90
一、双作用叶片泵·············································································.90
二、单作用叶片泵·············································································.92
任务四 柱塞泵······················································································.94
一、轴向柱塞泵················································································.94
二、径向柱塞泵················································································.96
任务五 液压泵的选用·············································································.97
练习题·································································································.103
项目十二 液压执行元件···············································································.104
任务一 液压马达··················································································.104
一、液压马达的作用和分类 ·······························································.104
二、液压马达的主要性能参数 ····························································.106
任务二 液压缸·····················································································.107
一、液压缸的类型及其结构特点 ·························································.107
二、液压缸的典型结构和组成 ····························································.113
练习题·································································································.116
项目十三 液压控制元件···············································································.118
任务一 概述························································································.118
一、液压控制阀的基本结构及工作原理 ················································.118
二、液压控制阀的分类······································································.119
三、液压控制阀的主要性能参数 ·························································.120
任务二 方向控制阀···············································································.120
一、单向阀·····················································································.120
二、换向阀·····················································································.121
任务三 压力控制阀···············································································.128
一、溢流阀·····················································································.128
二、减压阀·····················································································.133
三、顺序阀·····················································································.134
四、压力继电器···············································································.136
任务四 流量控制阀···············································································.138
一、节流口的结构形式及流量特性 ······················································.138
二、节流阀·····················································································.139
三、调速阀·····················································································.140
练习题·································································································.144
项目十四 辅助元件·····················································································.147
任务一 蓄能器·····················································································.147
一、蓄能器的用途············································································.147
二、蓄能器的类型············································································.148
三、蓄能器的安装与使用···································································.149
任务二 滤油器·····················································································.149
一、滤油器的作用和基本要求 ····························································.149
二、滤油器的类型及特点···································································.150
三、滤油器的安装与使用···································································.152
任务三 密封装置··················································································.152
一、密封装置的作用和要求 ·······························································.152
二、密封装置的类型和特点 ·······························································.153
练习题·································································································.155
项目十五 液压基本回路···············································································.156
任务一 方向控制回路············································································.156
一、换向回路··················································································.156
二、锁紧回路··················································································.157
任务二 压力控制回路············································································.158
一、调压回路··················································································.158
二、卸荷回路··················································································.159
三、保压回路··················································································.161
四、增压回路··················································································.162
五、减压回路··················································································.162
六、平衡回路··················································································.163
任务三 速度控制回路············································································.164
一、调速回路··················································································.164
二、增速回路··················································································.173
三、速度换接回路············································································.174
任务四 多缸工作控制回路······································································.176
一、顺序动作回路············································································.176
二、同步回路··················································································.179
三、互不干扰回路············································································.180
练习题·································································································.183
项目十六 典型液压系统···············································································.188
任务一 组合机床动力滑台液压系统 ·························································.188
一、概述························································································.188
二、YT4543 型动力滑台液压系统的工作原理·········································.189
三、YT4543 型动力滑台液压系统的特点···············································.191
任务二 数控车床液压系统······································································.192
一、卡盘夹紧与松开·········································································.193
二、回转刀架动作············································································.193
三、尾座套筒伸出与退回···································································.193
任务三 液压机液压系统·········································································.194
一、3150kN 通用液压机液压系统的工作原理·········································.194
二、3150kN 通用液压机液压系统的性能分析·········································.197
练习题·································································································.198
项目十七 液压系统的安装调试与维护 ····························································.201
任务一 液压系统的安装与调试 ·······························································.201
一、液压系统的安装·········································································.201
二、液压系统的调试·········································································.202
三、液压系统的使用与维护 ·······························································.203
任务二 液压系统的故障分析与排除 ·························································.203
一、液压系统的故障诊断步骤 ····························································.204
二、液压系统的故障诊断方法 ····························································.204
三、液压系统的常见故障分析与排除方法 ·············································.205
练习题·································································································.209
附录 A 常用气压与液压元（辅）件图形符号（摘自 GB/T 786.1—2021） ················210
参考文献····································································································.215