Design and Development of a Tractor Operated Walnut Harvester
摘要
The study was conducted to design and develop a Tractor operated walnut harvester for harvesting conventional walnut trees that have a height of about 50–60 feet. The developed harvester consists of a main frame, an eccentric disc mechanism to induce vibration, a fastening wire to transmit vibration, a clamp for holding the tree limb and a telescope pole to fix the clamping hook on the limb. The harvester was designed on the basis of the torque required to rotate the eccentric disc mechanism mounted on the main frame and attached to the tractor's three-point linkage. The key physico-mechanical properties of walnut trees, such as fruit detachment force, branch spring rigidity, limb length, diameter, and height, were assessed to determine the design parameters for the individual components of the walnut harvesting machine. The evaluation was carried out at three shaking frequencies (15, 20 and 25 Hz), stroke lengths (50, 100 and 150 mm) and shaking periods (20, 40 and 60 s). The optimization of the data through design expert 13.0.1 revealed that operating the machine at 20 Hz shaking frequency, 150 mm stroke length and a 60 s shaking period resulted in 96.35% fruit detachment percentage, 3.57% unharvested walnut percentage, 97.6% harvesting efficiency, 520 g/tree limb damage, and 491.7 kg h−1 as harvesting rate. The economic assessment served as the main criteria for judging the entrepreneurial potential of PTO operated walnut harvester. The cost of operation of the machine was calculated as 481.13 Rs h−1, and the unit cost of operation was found to be 0.67 Rs kg−1 of output. The developed machine was found to be economically viable and could be a viable solution to walnut harvesting.