2. Use mechanical methods to prevent loosening (1 adopt cotter pin and slotted nut 2. Use stop washer 3, use series steel wire);
3. Destroy the thread pair relationship to prevent loosening (1 side welding to death 2. End punch point 3. Bonding method);
Each method has its advantages and disadvantages. For details, please refer to the chapter on pre-tightening and anti-loosening of threaded connection in the Basis of Mechanical Design.