Study of Load Distribution and Sharing Characteristics of Planetary Geartrain for Wind Turbines

Most wind turbine gearboxes and pitch/yaw reducers consist of several planetary geartrains. Planetary geartrains allow gearboxes to be small, light, low noise, and efficient. The most important factors in the planetary geartrain design are load sharing among the planet gears and load distribution on the gear tooth flank. This study was conducted to analyze the load sharing and distribution in reducers with and without a slewing bearing. Load sharing and distribution of a pitch reducer without a slewing bearing were very uniform and even. However, in the other case, they were non-uniform and uneven, and the gear meshes were formed on the right or left. These results show that heavy loads act on the right or left flank of a meshed gear pair and reduce the gear life. Therefore, the slewing bearing must be considered when pitch/yaw reducers are designed and analyzed.