基于形位误差的框架式组合主轴回转精度预测

PREDICTION OF ROTARY ACCURACY OF FRAME-TYPE COMBINED SPINDLE BASED ON FORM AND POSITION ERRORS

框架式组合主轴在精密产品如数控转台和航空飞行模拟器中有广泛的应用,由于其组成零件中存在多项几何误差,直接影响框架式组合主轴的回转精度,进而影响轴线的精度。通过修正圆柱副的旋量表达,把三维圆柱度公差集成到框架式组合主轴的雅可比旋量公差分析模型,弥补了雅可比旋量模型不能处理形状公差的不足;在此基础上,对框架式组合主轴的回转基准进行建模与表征,利用极值法对框架式组合主轴中两工作轴段的同轴度误差进行求解,预测多项形位误差影响下框架式组合主轴的极限回转精度,测量结果证明方法的正确性。

Frame-type combined spindles are widely used in precision products such as CNC rotary tables and aerospace flight simulators.Due to the multiple geometric errors in their component parts,the rotary precision of the frame-type combined spindle is directly affected,which further affected the accuracy of the whole axis.In this paper,by correcting the small displacement torsor expression of the cylindrical pair,the three-dimensional cylindricity tolerance was integrated into the Jacobian torsor tolerance analysis model of the frame-type combined spindle.It made up for the deficiency that the Jacob torsor model could not deal with the form tolerance.On this basis,the rotary datum of the frame-type combined spindle was modeled and characterized.The coaxiality error of the two working shaft segments in the frame-type combined spindle was solved,and the limiting rotary precision of the frame-type combined spindle under the influence of the multinomial form and position errors was predicted.The measurement results proved the correction of the method.