Abstract: A mathematical model according to running - in performance simulation of double circular arc gears is established, which can describe the running - in procedure, and obtain the ideal running - in specification of double circular arc gears. The running - in regulation of double circular arc gears with ideal meshing and center distance errors case are analyzed. The contact patterns before and after running - in are presented, and the post running - in wear values are given. The calculating results are in accordance with that measured.

Key words: Double circular arc gears, Running- in Error