反向间隙误差对螺旋转子精铣精度的影响及其仿真

Influence of Opposite Clearance Error to the Precision of Spiral Rotor and its Simulation in Finishing Machining

为实现大模数少齿数螺旋转子的高效精加工,研究了数控机床旋转轴反向间隙积累误差对转子精加工法向齿厚的影响。首先建立螺旋面的方程并计算其法向矢量,求得球头铣刀精加工刀位数据;然后推导反向间隙积累误差的估算公式,分别采用空间环形走刀和空间平行走刀对转子加工过程进行仿真,得到走刀循环次数与反向间隙积累误差值之间的关系曲线。仿真结果和数控机床试切结果表明,当转子法向齿厚尺寸较小时,采用空间环形走刀方式效率较高且能保证精度;当法向齿厚处于临界值时,可以采用空间环形走刀,但需对端面型线作出一定角度的旋转以抵消误差积累;当法向齿厚较大时,应该采用空间平行走刀方式规划刀具路径。

In order to machine the spiral rotor with high efficiency, the influence of opposite clearance error to the precision of spiral rotor was researched. First, the equation of spiral surface was established to obtain the cutter location data, and the estimation formula of error accumulation of opposite clearance error was deduced. The numerical control （NC） machining process was simulated to obtain the relation curve between loop times and error accumulation according to the spatial loop tool path and spatial parallel tool path. The results of simulation and machining test show that the spatial loop tool path can work with high efficiency when the size of normal tooth thickness is small. When the thickness is near the critical value, the profile curve of rotor end should be rotated slightly to counteract the error accumulation. And when the thickness is large enough, the spatial parallel tool path should be adopted.