机械基础 （胥宏主编书籍）

内容简介

本书是为了适应职业教育的培养目标和教育特点，遵循“以必须、够用为度”和“强化应用、培养技能”的原则，突出中职教育特色而编写的。

本书共分7 章，内容包括：构件的静力分析、杆件的基本变形、机械工程材料、常用机构、机械传动、支承与连接零部件和液压传动系统。每章前面有学习目标，后面有本章小结，并附有大量的练习题供读者练习。

本书适用于机械、机电类等应用技术类专业的学生使用，也可作为相关行业人员的培训用书。

图书目录

绪论·································································································································· 1

第1 章 构件的静力分析······························································································· 5

1.1 静力学基本概念及静力学公理······································································· 5

1.1.1 力的概念······························································································· 5

1.1.2 刚体的概念··························································································· 6

1.1.3 平衡的概念··························································································· 7

1.1.4 静力学公理··························································································· 7

1.2 约束与受力图································································································ 10

1.2.1 几种常见的约束················································································· 10

1.2.2 受力分析与受力图············································································· 13

1.3 平面汇交力系································································································ 16

1.3.1 平面汇交力系合成的几何法······························································ 16

1.3.2 平面汇交力系合成的解析法······························································ 17

1.3.3 平面汇交力系的平衡条件·································································· 19

1.4 力矩和力偶···································································································· 21

1.4.1 力对点之矩························································································· 21

1.4.2 合力矩定理························································································· 21

1.4.3 力偶的概念························································································· 22

1.4.4 力偶矩································································································· 23

1.4.5 力偶的性质························································································· 23

1.4.6 平面力偶系的合成············································································· 24

1.4.7 平面力偶系的平衡············································································· 24

1.5 平面任意力系································································································ 26

1.5.1 力线平移定理····················································································· 26

1.5.2 平面任意力系向一点的简化······························································ 27

1.5.3 平面任意力系的平衡条件与平衡方程·············································· 30

1.5.4 平面平行力系的平衡········································································· 31

1.5.5 平面任意力系平衡方程的应用·························································· 34

1.5.6 物体系统的平衡················································································· 36

【本章小结】········································································································ 40

【习题】················································································································ 41

第2 章 杆件的基本变形····························································································· 48

2.1 材料力学的基本概念···················································································· 48

2.2 拉伸与压缩···································································································· 50

2.2.1 轴向拉伸与压缩基本变形及相关概念·············································· 50

2.2.2 轴向拉伸与压缩的应力分析······························································ 53

2.2.3 轴向拉伸与压缩时的强度计算·························································· 56

2.2.4 拉伸与压缩时的变形········································································· 59

2.2.5 静载荷作用下材料的力学性能·························································· 62

2.3 剪切和挤压···································································································· 66

2.3.1 剪切的实用计算················································································· 67

2.3.2 挤压的实用计算················································································· 68

2.4 圆轴的扭转···································································································· 70

2.4.1 外力偶的计算····················································································· 71

2.4.2 扭矩与扭矩图····················································································· 71

2.4.3 圆轴扭转时的应力分析····································································· 74

2.5 直梁的弯曲···································································································· 77

2.5.1 平面弯曲的基本概念及梁的类型······················································ 77

2.5.2 梁弯曲时的内力和内力图·································································· 78

2.5.3 梁的弯曲正应力················································································· 83

2.5.4 等截面梁的强度计算········································································· 85

2.5.5 提高弯曲强度的主要措施·································································· 86

【本章小结】········································································································ 88

【习题】················································································································ 89

第3 章 机械工程材料································································································· 94

3.1 金属材料的力学性能···················································································· 94

3.1.1 强度与塑性························································································· 95

3.1.2 硬度····································································································· 95

3.1.3 冲击吸收功和冲击韧度····································································· 96

3.1.4 金属的疲劳强度················································································· 97

3.2 钢铁材料········································································································ 97

3.2.1 碳素钢································································································· 97

3.2.2 合金钢································································································· 99

3.2.3 铸铁··································································································· 102

3.3 钢的热处理·································································································· 103

3.3.1 金属及合金的晶体结构··································································· 103

3.3.2 铁碳合金的基础知识······································································· 106

3.3.3 钢的热处理基本原理······································································· 109

3.3.4 钢的热处理工艺··············································································· 112

3.3.5 钢的表面热处理··············································································· 114

3.4 有色金属材料······························································································ 115

3.4.1 铜及铜合金······················································································· 115

3.4.2 铝及铝合金······················································································· 116

3.5 非金属材料·································································································· 117

3.5.1 工程塑料··························································································· 117

3.5.2 橡胶··································································································· 118

3.5.3 陶瓷··································································································· 118

3.5.4 复合材料··························································································· 119

【本章小结】······································································································ 120

【习题】·············································································································· 120

第4 章 常用机构······································································································ 122

4.1 机构和机构运动简图·················································································· 122

4.1.1 机构的组成······················································································· 122

4.1.2 机构运动简图··················································································· 124

4.2 平面连杆机构······························································································ 124

4.2.1 铰链四杆机构的基本形式································································ 125

4.2.2 平面四杆机构的其他形式································································ 128

4.2.3 平面四杆机构的基本特性································································ 130

4.3 凸 轮 机 构································································································ 135

4.3.1 凸轮机构的分类··············································································· 136

4.3.2 从动件的常用运动规律··································································· 138

4.3.3 盘形凸轮轮廓曲线的设计································································ 141

4.4 间歇运动机构······························································································ 144

4.4.1 棘轮机构··························································································· 144

4.4.2 槽轮机构··························································································· 146

【本章小结】······································································································ 147

【习题】·············································································································· 148

第5 章 机械传动······································································································ 150

5.1 带传动········································································································· 151

5.1.1 带传动的主要类型及工作原理························································ 151

5.1.2 摩擦型带传动的主要特点和应用···················································· 152

5.1.3 带传动的受力分析··········································································· 153

5.1.4 带传动的弹性滑动与传动比···························································· 155

5.1.5 V 带与V 带轮·················································································· 156

5.1.6 普通V 带传动的设计计算简介······················································· 160

5.1.7 带传动的张紧和维护······································································· 164

5.2 齿轮传动······································································································ 165

5.2.1 齿轮传动的类型及特点··································································· 165

5.2.2 渐开线齿廓······················································································· 167

5.2.3 渐开线标准直齿圆柱齿轮的主要参数和几何尺寸························· 170

5.2.4 渐开线标准直齿圆柱齿轮的啮合传动············································ 173

5.2.5 渐开线齿轮的加工方法··································································· 177

5.2.6 平行轴标准斜齿圆柱齿轮传动························································ 179

5.2.7 直齿圆锥齿轮传动··········································································· 183

5.2.8 齿轮的材料与齿轮的失效形式························································ 185

5.2.9 齿轮的结构及齿轮传动的润滑························································ 188

5.3 蜗杆传动······································································································ 190

5.3.1 蜗杆传动的类型和特点··································································· 190

5.3.2 圆柱蜗杆传动的主要参数和几何尺寸············································ 191

5.3.3 蜗杆传动的失效形式和常用材料···················································· 195

5.3.4 蜗轮回转方向的判定······································································· 196

5.4 齿轮系········································································································· 196

5.4.1 齿轮系的功用和分类······································································· 196

5.4.2 定轴齿轮系传动比的计算································································ 198

5.4.3 行星齿轮系传动比的计算································································ 201

【本章小结】······································································································ 203

【习题】·············································································································· 205

第6 章 支承与连接零部件······················································································· 209

6.1 轴················································································································· 210

6.1.1 轴的分类和轴的材料······································································· 210

6.1.2 轴的失效形式与设计准则································································ 212

6.1.3 轴的结构设计··················································································· 214

6.2 轴承············································································································· 218

6.2.1 滚动轴承的结构、特点和类型························································ 218

6.2.2 滚动轴承的代号及类型选择···························································· 221

6.2.3 滚动轴承的组合设计······································································· 225

6.3 轴毂连接······································································································ 228

6.3.1 键连接的类型··················································································· 229

6.3.2 键的选用··························································································· 230

6.3.3 花键的类型、特点和应用································································ 232

6.4 螺纹连接······································································································ 232

6.4.1 螺纹的类型、特点和应用································································ 232

6.4.2 螺纹连接的基本类型······································································· 235

6.4.3 标准螺纹连接件··············································································· 236

6.4.4 螺纹的预紧与防松··········································································· 238

6.5 联轴器和离合器·························································································· 239

6.5.1 联轴器······························································································· 240

6.5.2 离合器······························································································· 243

【本章小结】······································································································ 245

【习题】·············································································································· 245

第7 章 液压传动系统······························································································· 247

7.1 液压传动概述······························································································ 247

7.1.1 液压传动的工作原理······································································· 247

7.1.2 液压传动系统的组成······································································· 248

7.1.3 液压传动的特点··············································································· 249

7.1.4 液压系统的图形符号······································································· 249

7.2 液压传动的基础知识·················································································· 250

7.2.1 液压油的特性及选用······································································· 250

7.2.2 液压传动的两个重要参数································································ 250

7.3 液压元件······································································································ 253

7.3.1 液压泵······························································································· 253

7.3.2 液压缸······························································································· 256

7.3.3 液压控制阀······················································································· 259

7.3.4 液压辅件··························································································· 267

7.4 液压基本回路······························································································ 269

7.4.1 方向控制回路··················································································· 269

7.4.2 压力控制回路··················································································· 270

7.4.3 速度控制回路··················································································· 271

7.4.4 多缸动作回路··················································································· 273

7.5 液压系统实例······························································································ 274

【本章小结】······································································································ 275

【习题】·············································································································· 276

参考文献······················································································································ 280