The working principle of the electric torque wrench is that after the motor decelerates through the planetary gear mechanism, the power is transmitted to the impact head. The two convex heads of the impact head drive the pull shaft to rotate through the pull shaft claw, and the power output is completed by the pull shaft. After using for a period of time, the output power of the electric torque wrench began to drop. With the continuous use of the equipment, the output power continued to drop until it could not work.

其實，有用延長電扭矩動扳手的使用壽命，就一定要磨損問題。并且由于扳軸磨損比沖擊頭要更嚴重，所以，扳軸磨損的問題是關鍵。若此問題得以，沖擊頭磨損問題也就迎刃而解了。將整體式的扳軸改為拆分式的，扳軸的工作面可以拆卸，在使用一段時間后，可視其磨損情況進行更換。

In fact, to prolong the service life of the electric torque wrench, we must solve the problem of wear. And because the wear of the pull shaft is more serious than that of the impact head, the wear of the pull shaft is the key. If this problem can be solved, the problem of impact head wear will be solved. The working face of the pull shaft can be disassembled. After a period of use, it can be replaced according to its wear condition.

活動工作面可單獨選用適合的材料，通過合理的加工工藝過程，達到較高的機械性能。因此選用高碳鋼，進行先淬火后中溫回火的熱處理工藝。這樣加工后的活動工作面既有較高的硬度又有一定的韌性，使其在經(jīng)受沖擊時不會發(fā)生斷裂。且可以進行大批量的加工，一次加工即可滿足長期更換的使用要求。

Suitable materials can be selected for the movable working face, and high mechanical properties can be achieved through reasonable processing technology. Therefore, high carbon steel is selected for the heat treatment process of quenching first and then tempering at medium temperature. In this way, the working face after processing has both high hardness and certain toughness, so that it will not fracture when subjected to impact. And it can be processed in large quantities, and one processing can meet the requirements of long-term replacement.