Development and experiment of eccentric-type vibratory harvester for forest-fruits

For shortened and densely planted orchards in China, suitable mechanized operating condition was poor. In order to improve the harvesting efficiency of forest-fruit and reduce the harvesting cost, eccentric-type forest-fruit vibratory harvester was designed under mechanized operation for dwarf and close planting. The harvester was installed on electronic control tracklayer, which realized harvest with centrifugal force generated by circular motion of the eccentric block. Dynamic model of eccentric-type vibratory harvester was constructed, expression of response amplitude was derived and the main influencing factors on amplitude were analyzed. The walnut(J. regia 'Xinxin2') harvesting experiment was done with this harvester. Results showed that the shaking frequency had significant effect on both trunk amplitude and fruit removal rate（P=0.05）. The trunk amplitude and fruit removal rate increased at higher levels of shaking frequency, and reached the maximum values of 8.83 mm and 92.6% respectively when shaking frequency was 20 Hz with no fruit or tree damage. However, the clamp bark injury turned to be more apparent as the shaking frequency increased. Finally, shaking frequency was recommended at the range of 19-20 Hz, at which fruit removal rate was 89.5%-92.6% with no damage of the fruit or fruit tree. The study provides guidance for the practical production.