Bucket tooth subassembly, excavation mechanism and excavating machinery

The utility model discloses a bucket tooth subassembly, excavation mechanism and excavating machinery. The bucket tooth subassembly includes the toothholder, bucket tooth and overload protection structure, interact takes place at the bucket tooth during operation with the bucket tooth for overload protection structure at least, wherein, when effort that the bucket tooth was applyed the overload protection structure is less than the power allowable of overload protection structure, the bucket tooth keeps in the primary importance for the toothholder under the effect of overload protection structure, when effort that the bucket tooth was applyed the overload protection structure is more than or equal to the power allowable of overload protection structure, the bucket tooth removes for the toothholder and breaks away from from the primary importance. The technical scheme of the utility model do benefit to bucket tooth and relevant structure deteriorates such as toothholder and bucket body when preventing the bucket tooth overload.