基于滚珠丝杠的测量系统的设计与实现.doc

摘 要 滚珠丝杠是将角位移转化为线位移，或将线位移转化为角位移的理想产品，可以使传动和定位在同一零件上得到实现。另外，滚珠丝杠不但能够作为定位，传动零件，还可以起到定位的作用。由于使用滚珠作为其传递运动的媒介，使得滑动运动变为滚动运动，从而大大的减少了摩擦作用，提高的传动的效率。滚珠丝杠有效率高、精度高、微给进、使用寿命长等特点，因此，它成为了工具机械和精密机械上最常使用的传动元件。 在现代数控机床中，滚珠丝杠起了极其重要的作用。它作为数控机床运动系统中的传动，定位部件，其精度的高低往往直接决定着数控机床的加工精度。由于制造工艺和制造手段的限制，滚珠丝杠制造精度的提高已经变得十分困难，所以，高精度的滚珠丝杠检测手段就成为了补偿数控机床加工误差，提高机床加工精度的重要方式。另外，出于满足滚珠丝杠制造商对其出厂产品质量检验的需要，设计一种高性能的丝杠检验设备也是十分必要的。我国对滚珠丝杠的检测长期使用静态法，效率低下，且容易人为的引入误差。而现今国内使用的动态丝杠测量仪多采用单频、双频激光作为长度基准，圆光栅作为角度基准，共同作用来测量滚珠丝杠的行程误差。但其缺点是成本较高，只能对滚珠丝杠的一条母线进行测量，而不能对丝杠径向上的多条母线进行综合的评定。 本文以滚珠丝杠螺纹牙型曲线拟合为基本思想，将采用一种新的方式对丝杠的螺距误差进行测量，在实现径向多母线测量目的的基础上，尽量减少设备的制造成本。 关键词：滚珠丝杠；光栅位移传感器；多母线测量数控 ABSTRACT Ball screw shaft is a ideal product to turn angle displacement to line displacement, or line displacement to angle. It can implement both driving and locating at the same time. Besides driving and locating, it can be a measuring piece. Because of the use of ball as the media, it reduces the function of friction significantly, and improves the efficiency. Ball screw shaft has the virtue of high efficiency and precision, micro-diving, long life-span etc, therefore it becomes the most popular driving piece in tool-machine and precision-machine. In modern NC machine tool, ball screw shaft plays a very important role. As the driving and locating piece of the mobile system in NC machine tool, the pricison of ball screw shaft always affects the precision of machine tool. Because of the limit of manufacturing process and method, it is very difficult to improve the precision of the ball screw shaft. The measurement of ball screw shaft with high precision is the important approach to optimize the parameter of manufacture and improve the precision of NC machine tool. In China, static measurement has been widely used for a long time,which is low efficient and can bring man-made error. Recently ,the dynamic measurement system used in China usually adopts the double frequency interferometers as length benchmark and round raster as angle benchmark .