Study on a Ultra-precisely Joining Method using a Shrink Fitter

采用收缩接头将铝多边形镜与碳化硅自动式气轴承进行超精密连接。如果采用固定螺钉和弹簧等传统连接方法，不可避免地会使多面镜的镜面被电机产生的热量磨损。收缩滤镜可以解决镜面因温度升高而产生的变形问题。收缩配合比其他连接方法能更好地定位轴的位置。去年，我们通过数值分析设计了收缩过滤器的尺寸，其中镜面不能被电机产生的热量扭曲超过100nm。然后进行了实验，验证了收缩滤器的设计。通过收缩钳工连接后，多角镜的镜面必须用超精密车床切割到理想的100nm平面。这被称为二次切割。今年，为了避免二次切割，我们通过计算机模拟寻找了多边形反射镜的最佳形状。通常多角镜的镜面在旋转过程中受到离心力的作用，会变形到300nm左右。然而，人们认为，多边形反射镜的特殊形状可以使这种变形保持在大约100纳米以下。因此，我们通过计算机模拟检查了大约30或40个形状，最终找到了2或3个最佳形状，可以将变形保持在可容忍量以下（提交给JSME）。此外，还研究了其他拟合曲面的圆度对镜面变形的影响。制作了6组试件，并测量了每组试件的圆度。根据测量的圆度计算出收缩配合后的镜面形状。在实验中，用激光干涉仪ZYGO测量镜面。计算值与实测值吻合较好。因此，我们可以澄清圆度外的影响（将从JSME发表）。然而，同样清楚的是，如果圆度外为0，则不能省略二次切割。少

A shrink fitter was used to join an aluminum polygon mirror and a SiC self-acting air bearing ultra-precisely. It is inevitable that mirror surfaces of the polygon mirror will de wearped by heat gensrated from a motor if conventional joining methods, such as set screws and springs, are taken. The shrink fitter can resolve the deformation problem of the mirror surfaces caused by the temperature rise. The shrinkage fit gives better shaft location than the other joining methods.Last year we designed dimensions of the shrink fitter by a numerical analysis, in which the mirror surfaces could not be warped over 100nm by the heat generated from the motor. Then the experiment were carried out to check the design of the shrink fitter.After joining by the shrink fitter, the mirror surfaces of the polygon mirror have to be cut by a ultra-precision lathe to a desirable flatness of 100nm. This is called secondary cut. This year, to omit the secondary cut, we have searched optimum shapes of the poly … More gon mirror through computer simulation. Usually the mirror surfaces of the polygon mirror in rotation are deformed outwaed to some 300nm by a centrifugal force. However it is thought that special shapes of the polygon mirror can keep this deformation below some 100nm. So we checked some 30 or 40 shapes through the computer simulation and finally found out 2 or 3 optimum shapes which could keep the deformation below tolerable amount (submitted to JSME). Furthermore the effect out-of-roundness ofothe fitting surfaces on the deformation of the mirror surfaces was investigated. Six sets of specimens were prepared and the out-of-roundness of each specimen was measured. The shapes of the mirror surfaces sfter the shrink fit were calculated based on the measured out-of-roundess. In the experiment, the mirror surfaces were measured by the laser interferometer, ZYGO.The calculated values were in good agreement with the measured ones. Thus we could clarify the effect of the out-of-roundness (to be published from JSME). However it was also clear that the secondary cut could not be omitted if the out-of-roundness was 0. Less