In this paper

some problems about the vibration of two stage split flow double circular arc gear reducer used in pumping units were discussed. These problems include the method for building and solving vibration model and the vibration behavior analysis of the reducer. It was shown that the vibration response in the box is symmetric if the excitation is symmetric. The decisive factor affecting the vibration of the reducer is the gear tooth meshing quality of low speed stage. The meshing quality of high speed stage only affects the vibration of high speed shaft and gear ton it. The vibration around bearings is mainty afsected by the Y vibration of the gear near the bearings.