目前小四轮拖拉机发生半轴滚键的故障很多,滚键的原因主要有两个。一是半轴和刹车毂内套孔配合间隙不当;二是半轴硬度低。当半轴轴端斜度与刹乍毂内孔斜度有误差时,结合面积就会大大减少,轴和套产生间隙。在起动和急刹车时,键和键槽承受的负荷加大, At present, a small four-wheel tractor half-axis rolling a lot of failure, there are two main reasons for rolling. First half shaft and brake hub sleeve hole with improper gap; second half shaft hardness is low. When the half-shaft end of the gradient and the first brake hub bore gradient error, the combined area will be greatly reduced, the shaft and sleeve clearance. In starting and braking, the key and the key to bear the load increase,