Analysis of tooth contact for cylindrical gear with high-order topological modification and misalignment

Abstract

The tooth contact analysis model is introduced for cylindrical gear with high-order topological modification and misalignment. According to the generation principle of gear, the tooth surface equation of double-crowned gear by using worm grinding wheel is derived. Based on the gear meshing theory, a tooth contact model of cylindrical gear considering errors and high-order topological modification is established. Taking helical gears as an example, the effects of errors and four different combinations of modification curves on the contact marks and transmission errors of tooth surface were analyzed. Results show that the paths of contact change dramatically with different combinations of modification curves. With the increasing of the order of modification curve, the contact path transitions smoothly in the middle of the tooth width, while the total length of the major axis of the contact ellipses increase significantly compared with taking the quadratic parabola modification. With proper parameters of the modification, the apex of transmission error function is flatter and its amplitude decreases which further reduces the vibration of gear transmission to installation error. The finite element method is applied to validate the proposed analysis model. The results are basically consistent and the maximum error is within 3.5 %.