渐开线形转子是罗茨系列鼓风机的核心组件，在风机制造和使用中，转子的加工精度直接影响到风机的使用性能．针对两叶转子，在极坐标下利用渐开线形成原理提出了另外一种设计方法，即取渐开线段上有限参数点，通过计算得到所取参数点的极角和极径，描绘出各参数点后，用光滑曲线连接可设计出所需渐开线段．研究和试验结果表明：在极坐标下对转子型线进行理论设计与计算，可简化设计计算步骤，提高作图精度，便于数控机床进行编程加工等．同时，提出了仿形法、范成法、简易数控机床加工等转子型线加工方法 Involute rotor is Roots series blower core components, in the manufacture and use of fans, rotor machining accuracy directly affects the fan performance. Aiming at the two-lobe rotor, another design method is proposed by using the principle of involute formation under the polar coordinates. That is to say, the finite parameter point on the involute line segment is obtained. The polar angle and the polar radius of the parameter point are calculated, After the parameter points, smooth curves can be used to design the desired involute segments. The research and experimental results show that the theoretical design and calculation of the rotor profile under polar coordinates can simplify the design and calculation steps, improve the accuracy of drawing, and facilitate the programming and processing of CNC machine tools. At the same time, proposed a profiling method, Fan Chengfa, simple CNC machining and other rotor line processing methods