影像法测量齿轮径向跳动不确定度及误差处理

Geared ring radial runout uncertainty approval and result error processing in projection measurement

为解决齿轮离线单件测量中,需要额外配置心轴的工序,试验中对在无心轴的条件下,采用影像测量仪对齿轮测量进行了研究,并结合实例评定影像法测量的误差及不确定度。试验中通过回转工作台代替心轴,调整回转工作台中心与齿轮中心同轴,实现对不同规格齿轮径向跳动测量的目的。通过数据分析,找出测量过程中存在的系统误差为362μm,并对结果进行修正。通过测量不确定度A类和B类综合评定,和对统计控制的极差控制图分析,前者极限偏差比后者小35μm。而单值极限偏差与控制极差几乎一致,相差1μm。两种方法对齿圈径向跳动精度等级判定,得出相同的判定结果。由于被测机加工塑料齿轮在加工过程中受到机械力和温度影响,产生较大齿廓偏差,最终导致塑料齿轮齿圈跳动误差过大,超出国标规定齿轮精度范围。

To resolve the extra workload of spindle preparation in single part offline measurement of geared ring radial runout, an experiment is made to explore the errors and uncertainty of gear measurement by projection measurement appliance. When mea- suring, a rotation platform is put into function in stead of spindle, and keep coaxial with gear center, thus various gear can be measured. By analysis of data, the systematic error is 362prn, which can be corrected later as a correction value. Comparing maximum offset by the approval of A series uncertainty and B series uncertainty with range control chart in statistic control, the former result is 35μm less than the later one. However, the single value maximum offset is similar with control range, leave only 1μm margine. Two methods of approval of gear precision have the common result. Furthermore, a much large gear contour error causes a large geared ring radial runout, which is out of the range of GB standard of gear precision, by the reason of much mechanical strength and temperature in machining.