Influence of Bucket Tooth Wear on Cutting Force
According to the abrasion degree of bucket teeth, we divide the wear of test bucket teeth into three levels: zero level wear, that is, new bucket teeth without abrasion; Intermediate wear, i.e. the radial abrasion length of bucket teeth L = about 6mm, and the average length of abrasion surface B = about 22 mm; Heavy wear, i.e. the radial wear length of bucket teeth L ≥ 15mm, and the average length of wear surface B ≥ 30mm, which corresponds to the wear proportion of bucket teeth used in mines, and the length of wear surface is about 1 / 3 of the length of original bucket teeth. The back angle of the bucket tooth after wear is equal to 0, the U angle increases obviously during cutting, and the friction increases rapidly.
The following conclusions can be drawn from the test: the cutting force increases rapidly with the blunt wear of bucket teeth, especially in heavy wear, the wire cutting force is 6 times that before wear; the normal force increases rapidly with the blunt wear of bucket teeth. The normal force increases by about 3 times in intermediate wear and about 8 times in heavy wear. In December 1995, the cutting force test was conducted on the wheel bucket excavator in Yuanbaoshan. When the bucket teeth were seriously worn, the whole bucket tooth pants sleeve was broken, which was caused by excessive normal force; Macroscopically, in case of intermediate wear, the vibration of the machine itself is severe in the cutting process, and the excavation resistance increases significantly. During heavy wear, the vibration of the machine itself is abnormal during the cutting process, and serious vibration occurs in the working device. Obviously, working under such bad working conditions is extremely unreasonable for the excavator, which will not only cause damage to the transmission parts, but also greatly overload the power of the equipment, shorten the service life of the machine and reduce the production capacity.