Abstract: The present achievement in scientific research provides a new way for increasing the load-bearing capacity of large gear drives. A brief comparison of several existing designs and the matching of two-stage gearing drive overlapping factors are given. The design with normal module Mn= 20mm,and a stepped basic rack profiles are adopted. Safety coefficients of the strength calculation are also given in the paper. By the end of February 1988, this machine has been operating for more than six years. Tens of million tons ofs feel billets were successfully rolled using the new reduction gear. The outputs are more than three times of that produced by a reduction gear with involute profiles. It fully proves that the machine is higher in Load-bearing capacity, easier to manufacture, and guarantees more stable operation, lower noise, higher efficiency, than the reduction gear with involute profiles at the same operation condition. Bearing vibration also satisfies the specification as dictated by the standards of ISO, IS and VDI. Huge economic benefits have been gained since its installation, and this novel reduction gear is still functioning normally.

Key words: 连轧机, 双圆弧齿轮