2．力矩电机驱动的进给系统特点
图5为由力矩电机构成的回转工作台，这种回转进给系统具有如下特点：电机与回转工作台间不存在传动链，属“零传动”进给驱动，因而没有传动链误差，也无需机械维护，传动精度高，结构紧凑。
图5 力矩电机构成的回转工作台
3．力矩电机的基本参数力矩电机的基本参数包括：电机的外径、内径、定子长度高度、连续力矩和峰值力矩。表8-3列出了瑞士ETEL公司生产的TMA系列直线电机的型号和基本参数。
表2 瑞士ETEL公司生产的TMA系列力矩电机的型号和基本参数
normal align=center>型号
normal align=center>外径/mm
normal align=center>内径/mm
normal align=center>定子长度/mm
normal align=center>连续力（80oC）/N·m
normal align=center>连续力矩（130oC）/N·m
normal align=center>连续力矩（水冷）/N·m
normal align=center>峰值力矩/N·m
normal align=center>最大转速度/rpm
normal align=center>TMA 0100-010
normal align=center>120
normal align=center>60
normal align=center>40
normal align=center>0.97
normal align=center>1.29
normal align=center>
normal align=center>5.89
normal align=center>600
normal align=center>TMA 0100-030
normal align=center>120
normal align=center>60
normal align=center>60
normal align=center>2.75
normal align=center>3.64
normal align=center>
normal align=center>17.7
normal align=center>600
normal align=center>TMA 0100-050
normal align=center>120
normal align=center>60
normal align=center>80
normal align=center>4.49
normal align=center>5.91
normal align=center>
normal align=center>29.5
normal align=center>600
normal align=center>TMA 0100-070
normal align=center>120
normal align=center>60
normal align=center>100
normal align=center>6.22
normal align=center>8.16
normal align=center>
normal align=center>41.2
normal align=center>600
normal align=center>TMA 0100-100
normal align=center>120
normal align=center>60
normal align=center>130
normal align=center>8.79
normal align=center>11.5
normal align=center>
normal align=center>58.9
normal align=center>600
normal align=center>TMA 0140-030
normal align=center>160
normal align=center>60
normal align=center>70
normal align=center>6.6
normal align=center>8.8
normal align=center>16.8
normal align=center>26.2
normal align=center>550
normal align=center>TMA 0140-050
normal align=center>160
normal align=center>60
normal align=center>90
normal align=center>10.7
normal align=center>14.2
normal align=center>28.4
normal align=center>43.7
normal align=center>550
normal align=center>TMA 0140-070
normal align=center>160
normal align=center>60
normal align=center>110
normal align=center>14.7
normal align=center>19.5
normal align=center>40
normal align=center>61.2
normal align=center>550
normal align=center>TMA 0140-100
normal align=center>160
normal align=center>60
normal align=center>140
normal align=center>20.6
normal align=center>27.3
normal align=center>57.6
normal align=center>87.4
normal align=center>550
normal align=center>TMA 0140-150
normal align=center>160
normal align=center>60
normal align=center>190
normal align=center>30.5
normal align=center>40.3
normal align=center>86.6
normal align=center>131
normal align=center>550
normal align=center>TMA 0210-030
normal align=center>230
normal align=center>140
normal align=center>70
normal align=center>20.4
normal align=center>27.2
normal align=center>54.9
normal align=center>93.2
normal align=center>270
normal align=center>TMA 0210-050
normal align=center>230
normal align=center>140
normal align=center>90
normal align=center>33.1
normal align=center>44
normal align=center>93
normal align=center>155
normal align=center>270
normal align=center>TMA 0210-070
normal align=center>230
normal align=center>140
normal align=center>110
normal align=center>45.7
normal align=center>60.6
normal align=center>132
normal align=center>217
normal align=center>270
normal align=center>TMA 0210-100
normal align=center>230
normal align=center>140
normal align=center>140
normal align=center>64.5
normal align=center>85.3
normal align=center>190
normal align=center>311
normal align=center>270
normal align=center>TMA 0210-150
normal align=center>230
normal align=center>140
normal align=center>190
normal align=center>95.6
normal align=center>126
normal align=center>288
normal align=center>466
normal align=center>270
normal align=center>TMA 0290-030
normal align=center>310
normal align=center>220
normal align=center>70
normal align=center>40.6
normal align=center>54.2
normal align=center>114
normal align=center>208
normal align=center>180
normal align=center>TMA 0290-050
normal align=center>310
normal align=center>220
normal align=center>90
normal align=center>66.1
normal align=center>87.8
normal align=center>194
normal align=center>347
normal align=center>180
normal align=center>TMA 0290-070
normal align=center>310
normal align=center>220
normal align=center>110
normal align=center>91.3
normal align=center>121
normal align=center>274
normal align=center>486
normal align=center>180
normal align=center>TMA 0290-100
normal align=center>310
normal align=center>220
normal align=center>140
normal align=center>129
normal align=center>170
normal align=center>397
normal align=center>694
normal align=center>180
normal align=center>TMA 0290-150
normal align=center>310
normal align=center>220
normal align=center>190
normal align=center>191
normal align=center>252
normal align=center>600
normal align=center>1040
normal align=center>180
normal align=center>TMA 0360-030
normal align=center>385
normal align=center>265
normal align=center>90
normal align=center>78.5
normal align=center>105
normal align=center>202
normal align=center>294
normal align=center>180
normal align=center>TMA 0360-050
normal align=center>385
normal align=center>265
normal align=center>110
normal align=center>126
normal align=center>168
normal align=center>343
normal align=center>490
normal align=center>180
normal align=center>TMA 0360-070
normal align=center>385
normal align=center>265
normal align=center>130
normal align=center>172
normal align=center>229
normal align=center>485
normal align=center>686
normal align=center>180
normal align=center>TMA 0360-100
normal align=center>385
normal align=center>265
normal align=center>160
normal align=center>241
normal align=center>319
normal align=center>698
normal align=center>981
normal align=center>180
normal align=center>TMA 0360-150
normal align=center>385
normal align=center>265
normal align=center>210
normal align=center>354
normal align=center>468
normal align=center>1054
normal align=center>1471
normal align=center>180
normal align=center>TMA 0450-100
normal align=center>0
normal align=center>0
normal align=center>0
normal align=center>405
normal align=center>539
normal align=center>1149
normal align=center>1622
normal align=center>136
normal align=center>TMA 0530-030
normal align=center>565
normal align=center>420
normal align=center>90
normal align=center>192
normal align=center>259
normal align=center>508
normal align=center>700
normal align=center>140
normal align=center>TMA 0530-050
normal align=center>565
normal align=center>420
normal align=center>110
normal align=center>307
normal align=center>413
normal align=center>859
normal align=center>1166
normal align=center>140
normal align=center>TMA 0530-070
normal align=center>565
normal align=center>420
normal align=center>130
normal align=center>420
normal align=center>562
normal align=center>1213
normal align=center>1633
normal align=center>140
normal align=center>TMA 0530-100
normal align=center>565
normal align=center>420
normal align=center>160
normal align=center>586
normal align=center>782
normal align=center>1692
normal align=center>2332
normal align=center>140
normal align=center>TMA 0530-150
normal align=center>565
normal align=center>420
normal align=center>210
normal align=center>859
normal align=center>1145
normal align=center>2556
normal align=center>3499
normal align=center>140
normal align=center>TMA 0760-030
normal align=center>795
normal align=center>650
normal align=center>110
normal align=center>429
normal align=center>578
normal align=center>1146
normal align=center>1576
normal align=center>90
normal align=center>TMA 0760-050
normal align=center>795
normal align=center>650
normal align=center>130
normal align=center>685
normal align=center>920
normal align=center>1939
normal align=center>2626
normal align=center>90
normal align=center>TMA 0760-070
normal align=center>795
normal align=center>650
normal align=center>150
normal align=center>935
normal align=center>1253
normal align=center>2658
normal align=center>3676
normal align=center>90
normal align=center>TMA 0760-100
normal align=center>795
normal align=center>650
normal align=center>180
normal align=center>1305
normal align=center>1743
normal align=center>3826
normal align=center>5252
normal align=center>90
normal align=center>TMA 0760-150
normal align=center>795
normal align=center>650
normal align=center>230
normal align=center>1913
normal align=center>2550
normal align=center>5776
normal align=center>7878
normal align=center>90
normal align=center>TMA 0990-030
normal align=center>1030
normal align=center>870
normal align=center>110
normal align=center>758
normal align=center>1024
normal align=center>2040
normal align=center>2802
normal align=center>68
normal align=center>TMA 0990-050
normal align=center>1030
normal align=center>870
normal align=center>130
normal align=center>1212
normal align=center>1628
normal align=center>3455
normal align=center>4669
normal align=center>68
normal align=center>TMA 0990-070
normal align=center>1030
normal align=center>870
normal align=center>150
normal align=center>1654
normal align=center>2216
normal align=center>4880
normal align=center>6537
normal align=center>68
normal align=center>TMA 0990-100
normal align=center>1030
normal align=center>870
normal align=center>180
normal align=center>2307
normal align=center>3082
normal align=center>7025
normal align=center>9339
normal align=center>68
normal align=center>TMA 0990-150
normal align=center>1030
normal align=center>870
normal align=center>230
normal align=center>3383
normal align=center>4509
normal align=center>10600
normal align=center>13723
normal align=center>68
normal align=center>TMA 1220-030
normal align=center>1260
normal align=center>1100
normal align=center>110
normal align=center>1182
normal align=center>1596
normal align=center>3192
normal align=center>4379
normal align=center>55
normal align=center>TMA 1220-050
normal align=center>1260
normal align=center>1100
normal align=center>130
normal align=center>1889
normal align=center>2539
normal align=center>5406
normal align=center>7299
normal align=center>55
normal align=center>TMA 1220-070
normal align=center>1260
normal align=center>1100
normal align=center>150
normal align=center>2578
normal align=center>3454
normal align=center>7636
normal align=center>10219
normal align=center>55
normal align=center>TMA 1220-100
normal align=center>1260
normal align=center>1100
normal align=center>180
normal align=center>3595
normal align=center>4804
normal align=center>10670
normal align=center>14598
normal align=center>55
normal align=center>TMA 1220-150
normal align=center>1260
normal align=center>1100
normal align=center>230
normal align=center>5270
normal align=center>7026
normal align=center>16110
normal align=center>21897
normal align=center>55
三、数控机床导轨
1．对导轨的基本要求 机床导轨的功用是起导向及支承作用，它的精度、刚度及结构形式等对机床的加工精度和承载能力有直接影响。为了保证数控机床具有较高的加工精度和较大的承载能力，要求其导轨具有较高的导向精度、足够的刚度、良好的耐磨性、良好的低速运动平稳性，同时应尽量使导轨结构简单，便于制造、调整和维护。数控机床常用的导轨按其接触面间摩擦性质的不同可分为滑动导轨和滚动导轨。 2．滑动导轨 在数控机床上常用的滑动导轨有液体静压导轨、气体静压导轨和贴塑导轨。 1）液体静压导轨：在两导轨工作面间通入具有一定压力的润滑油，形成静压油膜，使导轨工作面间处于纯液态摩擦状态，摩擦系数极低，多用于进给运动导轨。 2）气体静压导轨：在两导轨工作面间通入具有恒定压力的气体，使两导轨面形成均匀分离，以得到高精度的运动。这种导轨摩擦系数小，不易引起发热变形，但会随空气压力波动而使空气膜发生变化，且承载能力小，故常用于负荷不大的场合。 3）贴塑导轨：在动导轨的摩擦表面上贴上一层由塑料等其它化学材料组成的塑料薄膜软带，其优点是导轨面的摩擦系数低，且动静摩擦系数接近，不易产生爬行现象；塑料的阻尼性能好，具有吸收振动能力，可减小振动和噪声；耐磨性、化学稳定性、可加工性能好；工艺简单、成本低。 3．滚动导轨 滚动导轨的最大优点是摩擦系数很小，一般为0.0025～0.005，比贴塑料导轨还小很多，且动、静摩擦系数很接近，因而运动轻便灵活，在很低的运动速度下都不出现爬行，低速运动平稳性好，位移精度和定位精度高。滚动导轨的缺点是抗振性差，结构比较复杂，制造成本较高。近年来数控机床愈来愈多地采用由专业厂家生产的直线滚动导轨副或滚动导轨块。这种导轨组件本身制造精度很高，对机床的安装基面要求不高，安装、调整都非常方便。直线滚动导轨副结构在第六章已介绍过，这里简要介绍一下滚动导轨块结构。 图6所示为一种滚动导轨块组件，其特点是刚度高、承载能力大、导轨行程不受限制。当运动部件移动时，滚柱3在支承部件的导轨与本体6之间滚动，同时绕本体6循环滚动。每一导轨上使用导轨块的数量可根据导轨的长度和负载的大小确定。1—防护板 2—端盖 3—滚珠 4—导向片 5—保护架 6—本体
图6 滚动导轨块结构
