Abstract: In order to compare the transmission performance of circular arc tooth trace cylindrical gear and traditional gear, according to the structural parameters of ZQA50 involute bevel reducer, the structural of CATT cylindrical gear reducer was designed, and models of the ZQA50 involute bevel reducer and CATT cylindrical gear reducer were created. Using UG/Open grip, the 3D model of CATT cylindrical gear was established with the help of the secondary development. Based on the relative motion between circular arc gear rack and blank, the gear cutting was completed. And then, the advantages and disadvantages of the transmission performance of the two main transmission structures were compared and analyzed by using the finite element method. The results show that the contact area of CATT cylindrical gear is near the middle section of the tooth width, and contact ratio is big.The maximum contact stress of CATT cylindrical gear is smaller than that of traditional gear.The stress on the transmission shaft satisfies the strength requirement. Namely, the transmission performance of CATT cylindrical gear is superior to the transmission gear.
Key words: circular arc tooth trace（CATT）; cylindrical gear; involute cylindrical gear; reducer; contact performance