Taking the circular arc tooth line cylindrical gear as the research object, two common machining methods (parallel link machining method and rotary cutter head milling method) of circular arc tooth line cylindrical gear are analyzed. Based on the above two processing methods, the tooth surface and tooth profile equations of circular arc tooth line cylindrical gear are given respectively, and the calculation expression of tooth thickness is deduced, and the influence of design parameters on tooth thickness deviation is analyzed.

The main conclusions are as follows

(1) the tooth profile of each section of gear machined by parallel connecting rod is involute, and the tooth thickness remains unchanged; the middle section of gear machined by rotating cutter head is involute, the other sections are hyperbolic, and the tooth thickness gradually decreases from the middle section to the end face;

The deviation of tooth width increases with tooth thickness. In the same section, from the root to the top of the tooth, the tooth thickness deviation gradually increases and the tooth thickness becomes thinner;

(3) in the middle section, the tooth profile radius has no effect on the tooth thickness deviation; in other sections, with the increase of the tooth profile radius, the tooth thickness deviation gradually increases and the tooth thickness becomes thinner. When the tooth line radius is small, the tooth profiles on both sides are even dry.