Abstract: The circumferential position error of planet wheel mounting hole is a common error in the manufacturing process of planetary gear train, which may directly change the gear contact length and meshing phase of the meshing tooth pair in planetary gear train. The abnormal vibration and noise are induced by the hole circumferential positon error as well as the poor load sharing between planet gears, which accelerate the failure of planetary gear teeth. A new planetary gear train dynamic model considering hole circumferential positon error is proposed for the unclear exciting mechanisms of hole circumferential position error. In the proposed model, the relationships among contact line location, pressure angle, location angle and hole circumferential position error are studied, the contact line length fluctuation and meshing phase are discussed, and finally the dynamic responses of planetary gear train in the present of hole circumferential position error are obtained. The simulated results show that the hole circumferential position error directly leads to the phase and amplitude change of gear meshing stiffness; the load sharing characteristics,vibration displacement and dynamic transmission error of planetary gear train become worse, and an obvious modulation phenomenon has been found in the the vibration displacement. Finally, a carrier frame hole circumferential position error experiment is conducted to validate the correctness and effectiveness of the proposed method. Key

Key words: planetarygeartrain, planetwheelmountingholecircumferentialpositionerror, meshingphase, contactlinelength, transmissionerror, vibrationcharacteristic