Wheeled integrated machine for camellia fruit harvesting on the hillside

Camellia oil is one of the most significant woody oil crops in the hilly and mountainous regions of south China. Manual harvesting cannot fully meet the large-scale production, due to the minimal site conditions, tree management, and mechanization levels. Fruit harvesting has significantly hindered the rapid development of the camellia oil industry, particularly for the labor-intensive, time-consuming, and costly. Therefore, mechanical harvesting has been crucial to increase the self-sufficiency rate for the large-scale production of camellia oil. In this study, a wheeled integrated harvester was designed to harvest the camellia oleifera fruits. There was the walking mechanism (chassis, and control system), a connecting mechanism (connecting device), and an operating mechanism (harvesting device, collection and conveying device), with a power rating of 17 kW. The walking wheel was designed as the iron high-pattern rubber wheel. The grip has fully met the requirement of walking on slopes. Rapid harvesting and automated collection were realized for the Camellia oleifera fruits. The machine was measured by 2.34 m in length, 0.8 m in width, and 1.15 m in height. The picking device and collection system were connected to the chassis via a lifting device. The harvesting mechanism was maintained perpendicular to the trunk during operation on slopes. The lifting device was used to control the position of the operating mechanism, according to the passing performance and operational requirements of the machine. The structure of the whole harvesting machine was more compact, according to the vibration theory of fruit picking. The tree body was vibrated to keep the machine still. It was necessary to reasonably arrange the machine components for the vibration isolation. Specifically, the vibration generator was placed behind the conveying mechanism and flexibly suspended on the frame. A chain delivery device was designed to meet the requirements of camellia fruit delivery. The comparative tests were conducted on the speed and transmission at the linear speed of 2.0 m/s. The key contact components were optimized to obtain a final fruit harvesting rate of 93.1% and a damaged fruit rate of 1.1%. Elongated holes were used to remove some impurities on the bottom of the equipment's distribution device and the concave surface of the contact part. Some impurities were removed to automatically screen during delivery. The wheeled chassis power and structure were matched to meet the requirements of chassis layout and power transmission. The installation angle of the diesel engine was adjusted with the slope. The main transmission was used as a worm gear system. Safe parking was realized to ensure the engine's reliability and safety on slopes. Test results show that the harvester was operated efficiently to cover 40 trees per hour, with a picking net rate exceeding 85% and a flower loss rate below 8%. The speeds of the machine ranged from 0 to 5 km/h, with a height adjustment range of 0 to 300 mm. The machine was used to climb the slopes with an angle of up to 19° and a maximum lateral tipping angle of 15°, meeting all operational requirements for slope terrain. Standardized and mechanized camellia oleifera planting is crucial to the structural design and efficient use of machinery. The integrated machinery can be expected to achieve the maximum efficiency of production.