关键词: 弧齿锥齿轮, 铣齿机, 主动精度设计, 精度分配, 重复定位精度, 误差模型, 精度模型

Abstract: To design the NC axis'repeatability positioning precision of spiral bevel gear milling machine tool reasonably,the active precision design method of spiral bevel gear milling machine tool oriented to the machining precision requirements of parts was proposed.First,the structure and machining principle of NC spiral bevel gear machine tool was analyzed,the tooth surface equation of spiral bevel gear was established with coordinate transformation,and the mapping relationship between tooth surface machining error and NC axis'motion error which named tooth surface machining error model was established by selecting the tooth pitch deviation as the tooth surface error inspecting item.Second,the machining precision requirements of parts was expressed with process capability index Cp and total standard deviation of product characteristic value σw,the expression of NC axis'repeatability positioning precision defined by 4σ principle,and the mapping relationship between tooth surface machining precision and NC axis'repeatability positioning precision which named tooth surface machining precision model was established by combining the standard deviation σ of NC axis'motion error in the tooth surface machining error model.Then,the machining precision requirements of spiral bevel gear was decomposed into NC axis'repeatability positioning precision of spiral bevel gear milling machine tool according to the equal action error distribution principle.The NC axis'repeatability positioning precision of YK2275 spiral bevel gear milling machine tool with six level precision was designed,and the feasibility of the proposed method was verified with the machining precision test of prototype.

Key words: spiral bevel gear, milling machine tool, active precision design, precision distribution, repeatability positioning precision, error model, precision model