齿轮法向啮合齿廓及其测量

Gear profile of the path of contact and its measurement

法向啮合齿廓是齿轮齿面上能反映齿轮的加工与传动质量的一条工程意义独特的曲线,在齿轮滚齿、蜗杆砂轮磨齿等展成法加工中,是齿面加工的形成曲线,在渐开螺旋齿轮传动中,是齿轮传动的工作曲线。然而,现有的齿轮测量仪器并没有法向啮合齿廓的测量功能。结合法向啮合齿廓的形成原理,给出了其理论模型,基于现有齿轮测量中心,提出了法向啮合齿廓偏差测量的四坐标测量法和三坐标测量法。测量实践表明,采用现有的齿轮测量仪器,能方便的实现法向啮合齿廓偏差测量与评定,四坐标法测得的法向啮合齿廓形状偏差、倾斜偏差和总偏差与三坐标法的测量结果相比分别相差0.2、1.3、0.6μm。与渐开线和螺旋线相比较,法向啮合齿廓具有综合性、统一性和唯一性,通过对渐开线偏差和螺旋线偏差的相互补偿,可优化对法向啮合齿廓的控制,有效降低对渐开线和螺旋线的精度要求。

Profile of the path of contact(PPC),as a characteristic curve on the gear tooth surface,is with specific engineering significance.It can reflect the quality of gear machining and gear transmission.The PPC is not only the generative curve in gear hobbing,worm grinding and other generative machining,but also the working curve in the involute gear transmission.However,there is no function to measure the deviation of PPC for the existing gear measuring instruments.The theoretical model of the PPC is presented,which is based on the gear geometry.By means of the existing gear measuring center,the four-coordinate method and the threecoordinate method for measuring the deviation of PPC are proposed.The measurement practice indicates that the measurement and evaluation of the PPC can be realized by using the existing gear measuring instruments.The form deviation,slope deviation and total deviation of the PPC measured by the four-coordinate method are 0.2,1.3,and 0.6μm,which are different from those measured by the three-coordinate method.Compared with the gear involute and helix,the PPC has features of comprehensiveness,unity,and uniqueness.The optimal deviation of PPC is obtained through synthesizing the involute deviation and helix deviation of the gear,which effectively reduces accuracy requirements for the gear involute and helix.