目录1.绪论···········································································································12.主传动系统的组成及要求···················································································23.主传动系统的运动设计······················································································43.1转速图·······································································································43.2结构网与结构式···························································································93.3转速图的拟定····························································································103.4带轮及V带设计·························································································153.5齿轮齿数的确定·························································································173.6齿轮各项参数的确定···················································································224.主传动系统的结构设计·····················································································254.1主传动系统的布局及变速机构的类型······························································254.2齿轮的布置·······························································································264.3轴的空间布置····························································································284.4计算转速··································································································294.5主轴轴径设计····························································································324.6主传动系统的开停装置················································································354.7主传动系统的制动装置················································································355.传动系统的润滑······································································错误！未定义书签。5.1润滑系统的要求·························································································365.2润滑剂的选择····························································································365.3润滑方式··································································································376.参考文献·······································································································39
Ⅰ1.绪论金属切削机床（以下简称机床）是用刀具或磨具对金属工件进行切削加工的机器。在一般机械制造工厂中，机床约占机器设备总台数的50—70%，它所担负的工作量约占总劳动量的一半。
现代化工业生产主要表现在生产总量的提高与先进的技术指标两方面，而这些则取决于机械制造工业提供的装备的技术水平、机床工业是及其制造业的重要部门，担负着为农业、工业、科学技术和国防等现代化提供技术装备的任务，在整个国民经济中占有重要地位。一个国家机床工业的技术水平。机床的拥有量和现代化程度是这个国家工业生产能力核技术水平的重要标志之一。
我国机床工业从无到有，从小到大，从修配到制造，从纺织到自行设计，从沿海到内地，从通用机床到专用机床，从单机到配套，不断发展壮大。目前，我国的机床工业体系已经基本形成，并设计和制造了一些具有先进水平的机床，逐步掌握了精密、高效、简短、重型等机床品种。许多工厂已试制和生产了数控车床、数控铣床、数控镗床以及加工中心。机关技术、静压技术、数显装置、电子计算机等也成功地用到机床上。
虽然我国的机床工业取得了巨大的成就，但还不能满足国防建设和工业告诉发展的需要，特别是在质量和品种方面，在重型机床和高效机床方面，在基本理论和试验研究方面，与世界先进水平相比还存在一定的差距。
第1页共40页2．主传动系统的组成与要求机床的主传动系统是用来实现机床的主运动的，它与机床的传动方案和总体布局有关，对于机床的使用性能、结构和制造成本都有明显的影响。因此在设计机床的过程中必须给予充分的重视，以便制定出既满足使用要求有经济合理的方案。
铣床的主传动装置和零件全部装在床身中，是整体式的结构，为了满足工作性能的要求，从电动机起，至机床工作的执行部件（主轴），主传动系统通常包括下列几个组成部分：
1.定比传动机构2.变速装置
机床的变速装置有齿轮变速机构，机械无级变速机构以及液压无极变速装置等，其中最常见的是齿轮变速机构。
3.主轴组件
机床的主轴组件有主轴、主轴支承和安装在主轴上的传动件等。4.开停装置
用来控制机床主运动执行部件（主轴）的启动和停止，通常采用离合器或直接开停电动机。
5.制动装置
用来使机床主运动执行部件（主轴）尽快地停止运动，通常可以采用机械的、液压的或电动机的制动方式。
6.换向装置
用来改变机床主运动的方向，对于需要换向的机床，在设计主传动系统时，都应设有换向装置。他们可以是机械的、液压的，用来直接改变电动机的旋转方向。
7.操纵机构
机床的开停、变速、制动及换向等，都需要通过操纵机构来实现。设计机床时，一般是将主传动系统的设计方案与操纵机构同时加以考虑。
8.润滑与密封装置
为了保证主传动系统的正常工作，必须要良好的润滑与密封装置，防止出现漏油、
第2页共40页即具有固定传动比的传动机构，常采用齿轮、皮带及链传动等
漏水和漏气现象。
9.箱体
各机构和传动件的支承均装入箱体中，并保证他们相互位置的准确性。机床主传动系统与整台机床技术经济指标有密切的联系。例如机床的主轴转速范围、转速级数及电动机功率将直接影响这台机床的使用范围，主轴组件的精度、刚度、抗震性及温升对加工质量有重要的影响。总之，设计主传动系统时，一般应满足下面的几项要求：
（1）机床的主轴须有足够的转速范围和转速级数（对于主传动系统为直线运动的机床则为直线速度的变速范围和变速级数），以满足实际使用要求。
（2）主电动机和全部机构要能传递足够的功率和扭矩，并具有较高的传动效率。（3）执行部件（如主轴组件）需有足够的精度、刚度、抗震性以及小于许可限度的热变形。
（4）操纵要轻便灵活、迅速、安全可靠，并便于调整和维修。（5）结构简单、润滑与密封良好，便于加工和装配，成本低。
第3页共40页3主传动系统的运动设计主传动系统的运动设计是运用转速图的基本原理，以拟定满足给定的转速数列的经济合理的传动系统方案，其主要内容包括选择变速组数及传动副数，确定各变速组中的传动比，以及计算齿轮齿数和皮带轮直径等。如运动参数的确定，运动参数是指机床执行件如主轴、工件安装部件（工作台、刀架）的运动速度。1．主轴转速的确定
主运动为旋转运动的机床，主轴转速n由切削速度v和工件或刀具的直径d来确定：
n?1000v?d(r/min)
（2.3）
2.主轴最高转速和最低转速的确定
对于数控机床，为了适应切削速度和工件或刀具直径的变化，主轴的最高、最低转速可由下式确定：
nmax?nmin?
1000vmax?dmin1000vmin?dmax
（2.4）(2.5)
式中
nmax、nmin——主轴的最高、最低转(r/min)；
；vmax、vmin——最高、最低的切削速度（m/min）
dmax、dmin——相应最大、最小计算转径(mm)；
3．主轴的变速范围Rn
主轴的最高转速与最低转速之比值，称为主轴的变速范围，用Rn表示,即：
Rn?
Rn?
nmax1600
??48nmin33.5nmaxnmin
即
第4页共40页
机械设计课程设计_《卧式铣床设计说明书》
