This is a basic study for the performance evaluation and optimal design of the 78 kW class tractor PTO (Power-Take-Off) during baler operation. For this reason, the PTO torque according to the bale pressure was collected using a load measurement system, and the equivalent torque was analyzed. In order to accurately set the bale pressure level, a bale pressure measurement system was developed using a proximity sensor and load cell. In addition, a load measurement system was developed using a PTO torque meter and DAQ (Data Acquisition) to measure the PTO load according to the bale pressure. The bale pressure level is configured to be set by adjusting the distance of the proximity sensor. The bale pressure was measured by setting the distance of the proximity sensor to 5 and 10 mm, and bale pressures were found to be about 7.01 and 16.78 gf/cm2, respectively. As a result of measuring the PTO load under the same bale pressure condition and calculating the equivalent torque for 5 and 10 mm were found to be 357.15 and 538.48 Nm, respectively. The PTO equivalent torque increased by about 33% as the bale pressure increased. The equivalent PTO torque for 5 and 10 mm were found 45 and 17% lower than the the tractor maximum PTO torque, which was 654 Nm. It was observed that the PTO equivalent torque was lower than the tractor PTO maximum torque during baler operation. Therefore, it is necessary to perform PTO performance evaluation and optimal design in consideration of the equivalent torque generated according to the bale pressure during actual baler operation.
Figures & Tables
Fig. 1. A photo of agricultural tractor and round baler for load measurement used in this study