Research on pitch error phase matching of herringbone star gear system considering multi-tooth with different backlash

Pitch error is inevitable in gear machining, and it will aggravate the vibration and noise of the herringbone star gear train (HSGT). Although the machining accuracy is limited, the dynamic performance of the system can be further improved by appropriately combining the error phases. In this work, according to the periodicity of the pitch error and its influence on the backlash, the different backlash formed by the meshing tooth pairs during the transmission is deduced, then the meshing state and error excitation force of each tooth pair are considered, respectively. A new dynamic model of HSGT considering multi-tooth with different backlash under the influence of pitch error is established, and the reliability of the model is verified by the vibration experiment of the gearbox. Based on the proposed model, the influence mechanism of the error phase adjustment on two-sides of the herringbone center gear on the load-sharing performance is analyzed, and the optimal error phase combination of three parallel star gears is explored. When the pitch error value is constant, this research can guide the error phases combination of each herringbone gear in the HSGT, thereby reducing the vibration and improving the load-sharing performance of the system.