Safety factor of PTO gear of 105 hp agricultural tractor using measured field data

Abstract.

In this study, the safety factor of the PTO (Power Take Off) gear of an agricultural tractor during rotary tillage and was analyzed using Romax Designer, which is specialized for gearbox analysis. The real field data, PTO torque and PTO rotation speed, during the rotary tillage was obtained through the measurement system. The PTO torque meter consisted of strain-gauge sensors to measure the torque on the transmission and PTO input shafts. After modeling the PTO gear, simulation conditions were set. The input torque and rotation speed used real field data, and the real torque, rotation speed data were converted into the equivalent torque and equivalent rotation speed. The duration time was 304 hours. The stress and safety factors were calculated based on ISO 6336. The simulation shows that the contact safety factor of the PTO gear at the rated torque is smaller than that at equivalent torque during rotary tillage. The bending safety factor at the rated torque is smaller than that at equivalent torque during rotary tillage. Commonly, the PTO gear is designed under rated torque conditions, which may lead to overdesign. Therefore, when the PTO gear is designed, considering the field operation type and severity is necessary.