纵轴流联合收获机关键部件改进设计与试验

Improved design and test of key components for longitudianl axial flow combine harvester

针对当前履带式纵轴流联合收获机中存在的工作状态无法在收获不同作物间快速转换,割台损失率较高、脱粒分离能力较差以及功耗高等不足,对割台、脱粒、清选、行走等主要工作部件进行了改进设计与试验研究。将割台设计为无级调速可伸缩式结构,脱粒装置改为纵轴同径差速滚筒脱粒装置,采用单HST(hydro static transmission)原地转向行走装置及防粘附清选装置,并经室内试验和田间试验表明:可伸缩割台能实现稻麦收割状态与油菜收割状态的快速转换,扩大了割台的使用功能,收获油菜损失显著减少,与常规相比较,油菜损失率降低2.8个百分点;差速轴流滚筒提高了脱粒效果和分离能力,与等长度单转速轴流滚筒相比,夹带与脱不净损失率分别减少了0.02个百分点与0.09个百分点,破碎率减少了0.017个百分点;原地转向行走机构减少了地表土壤的破坏并降低了转向功耗,以原地转向替代单边制动转向时,节约功耗37.0%;清选机构抖动板和清选筛面经不沾水处理,改善了潮湿谷物的清选性能,清选损失率降低0.9个百分点,含杂率降低0.4个百分点;这些联合收获机主要工作部件的改进设计提高了整机工作性能,以期为联合收获机主要工作部件改进,提高联合收获机工作性能提供参考。

In view of the current state that the crawler-type vertical axial flow combine harvester can not be quickly converted between different crops, small radius steering is easy to cause surface soil damage, non-differential threshing drum is not suitable for high yield crop threshing, and without anti vibration water treatment the screen surface can not adapt to the cleaning processing of the crop with high water content, the loss rate of the cutting table is high, the threshing separation ability is poor, and the power consumption is high, we have improved the design and experiment of the main working parts such as cutting, threshing, cleaning and walking parts. The cutting table was designed to be a stepless speed adjustable telescopic structure, the threshing device was designed to be a longitudinal-axis roller with the same diameter and different speed, and a single HST （hydro static transmission） in situ steering walking device and an anti adhesion cleaning device were adopted. The results of laboratory tests and field tests showed that： The retractable cutting table could realize the fast conversion between the rice/wheat harvest state and the rape harvest state, and enlarge the use function of the cutting table; the loss of rapeseed was significantly reduced, and compared with the conventional method, the loss rate of rape was reduced by 2.8 percentage point. The threshing and separating device with the same diameter and differential speed could make use of the different speed of the threshing cylinder, and the threshing effect and separation ability were improved at the same time. Compared with the equal length single speed axial flow roller, the net loss rate of entrainment and removal decreased by 0.02 percentage point and 0.09 percentage point respectively, and the crushing rate was reduced by 0.017 percentage point. When the steering wheel was turned to a single side in wet field, the brake track was dragged on the surface of the ground, and the mud was accumulated. However, when a single hydraulic motor was used to steer the transmission, the steering would not occur. The conventional steering mechanism realized the steering with one side of the track brake, and consumed the braking power considerably; the in-situ steering had no braking, and both sides of the track were reversed. In-situ steering mechanism reduced surface soil damage and steering power consumption, and the power consumption was reduced by 37% when the steering was replaced by the single side. Cleaning mechanism and cleaning sieve after water repellent treatment shook board surface, which improved wet grain cleaning performance, and the loss rate was reduced by 0.9 percentage point and the impurity rate was reduced by 0.4 percentage point. The improved design of the main working equipment of the combine harvester improves the working performance of the whole machine.