履带收获机变速箱点蚀、打齿故障分析  

Analysis of Corrosive Pitting and Mis-engagement Problems on Crawler Harvester Gearboxes

作　　者：周良田 Zhou Liangtian(ZOOMLION AGRICULTURE MACHINERY CO.,LTD.,Wuhu,Anhui 241080,China)

机构地区：[1]中联农业机械股份有限公司,安徽芜湖241080

出　　处：《绿色科技》2020年第14期230-232,243,共4页Journal of Green Science and Technology

摘　　要：指出了履带谷物收获机经常在水田、烂泥田作业,变速箱使用工况恶劣,负载大,使用400 h后故障率偏高,主要失效模式是换挡变速齿轮、挡位齿轮出现点蚀、打齿的现象。结合变速箱市场故障,经过厂内各种方案验证、排除,发现履带收获机打齿的主要原因有两个:一是啮合宽度只占齿轮宽度的59%;二是拨叉在换挡滑杆上的锁定力不足,在收获机行驶阻力较大时易脱挡,而齿轮在滑脱的瞬间因接触区极小而造成齿边缘压变形,造成接触区进一步减小,从而使得齿面承载力进一步下降,从而造成点蚀、打齿。为此,提出了改变齿轮倒角,以增加齿轮接触宽度;加大换挡滑杆拨叉锁定力,以防止脱挡,结果表明:大幅度提高了作业过程齿轮承载力,消除了脱挡瞬间造成齿面压溃问题,经厂内、市场验证,变速箱点蚀、打齿故障率大幅度下降。Crawler grain harvesters are often operated in paddy fields and muddy fields.Gearboxes are used in bad conditions with large loads and the failure rate is high after 400 working hours.The main failure is that shift gears are pitted and mis-engaged.Under the gearbox market failures condition,factones got various schemes of verification and elimination.It is found that there are two essence reasons for gear mis-engagement failure of the crawler harvesters.One is the gear engagement width only accounting for 59%of the gear width;the other is that the locking force for the shift fork imposed on the slide bar is insufficient,and it is easy to disengage when the driving resistance of harvesters is large.The gear edge is deformed due to the extremely small contact area at the moment of slipping,resulting in a further increase in the contact areas,which makes bearing capacity of the gear surface further reduced,causing corrosive pitting and mis-engagement.By changing the chamfering of the gear,the contact width of the gear is increased;by increasing the locking force of the shifting lever fork,the disengagement is prevented and the bearing capacity of the gear during the operation is greatly improved and the problem of gear surface crushing caused by instantaneous disengagement is eliminated.After verification in the factory and the market,corrosive pitting and mis-engagement problem rate are dropped significantly.

关 键 词：履带谷物收获机 变速箱 啮合宽度 脱挡 点蚀 打齿 

分 类 号：S225[农业科学—农业机械化工程]