Effects of bearing characteristics on load distribution and sharing of pitch reducer for wind turbine

Abstract

The most important design factors in the life of a pitch reducer for a wind turbine are the load distribution on the contact surface of the gear teeth and load sharing among the planet gears. The effects of the output shaft bearing of the pitch reducer of a wind turbine on the load distribution and load sharing were analyzed in this study. Using commercial software, four pitch reducer models with different clearances and types of output shaft bearings were constructed, and the resulting load distribution and load sharing characteristics were analyzed. The results show that using a combination of tapered roller bearings reduces the gear’s face load factor and mesh load factor, thus improving the load distribution and load sharing characteristics, better than a combination of spherical roller bearings (SRB) and cylindrical roller bearings (CRB). A smaller radial internal clearance was found to be better when the SRB–CRB combination is used. To analyze the load distribution and load sharing of the planetary gear train, it was essential to model all the elements that constituted the pitch reducer in detail and then analyze the system characteristics, taking into consideration the interactions among the elements.