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结构形式可变换的柔性夹具装有可变更结构排列的零件（例如针形颊板，多片式零件和片状夹板)，标准工件的非专用夹持或夹紧元件（例如：启动标准夹持夹具和带有可移动元件的夹具配套件），或者装有陶瓷或硬化了的中介物质 (如：流动粒子床夹具和热夹具紧夹具）。为了生产，零件耍在夹具中被紧固， 需要产生夹紧作用，其有几个与夹具柔顺性尤关的步骤：根据被加工的即基础的部分和工作特点，确定工件在夹具中的所需的位置,接着必须选择苦干稳定平面的组合，这些稳定平面就构成工件被同定在夹具中确定位置上的夹持状轮廓结构，均衡所有各力和力矩，而且保证接近工件工作特点。最后，必须计算、调整、 组装可拆装的或标准夹具元件的所需位,以便使工件牢牢地被夹紧在夹具中。 依据这样的程序，夹具的轮廓结构和装合的规划和记录过程可以进行自动化控制。源'自^751;文,论`文'网]www.751com.cn
结构造型任务就是要产生若干稳定平面的组合,这样在这些平面上的各夹紧力将使工件和夹具稳定。按惯例，这个任务可用人一机对话即几乎完全自动化的方式来完成。一人一机对话即以自动化方式确定夹具结构造型的优点是可以有组织有规划进行夹具设计，减少所需的设计人员，缩短研究周期和能更好地配置工作条件。简言之，可成功地达到显著提高夹具生产效率和效益。
在充分准备了构造方案和一批材料情况下，在完成首次组装可以成功实现节约时间达60%。因此夹具机构造型过程的S的足产生合适的编程文件。
GEAR AND SHAFT INTRODUCTION
Abstract:
The important position of the wheel gear and shaft can't falter in traditional machine and modern machines. The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is pided into many model numbers, using for many situations respectively. So we must be the multilayer to the understanding of the wheel gear and shaft in many ways.
Key words: Wheel gear; Shaft
In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel lo each other. There are also other reasons, as we shall learn.
Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an in volute helicoids. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an in volute curve. The surface obtained when every point on the edge generates an in volute is called an in volute helicoids.
The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point，which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation: in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel oil the thrust load.