● Improper assembly. When the motor is not in the same direction as the device being driven, the motor is subjected to excessive radial loads, which eventually leads to metal fatigue. When the radial load on the extension end of the motor shaft is too large, the motor shaft is bent and deformed in the radial direction. When the motor rotates, the shaft is deformed by the torsion force in all directions, and finally the motor shaft is broken, and the fracture position is generally close to the bearing.
For the motor with pulley connection, but some customers give the motor output shaft with pulley, because the pulley is too heavy or the belt is installed too tight, it will cause the motor output shaft to continue to be subjected to variable stress during the operation of the motor. The maximum bending moment generated on the shaft is near the fulcrum of the output shaft bearing, and the repeated impact causes fatigue, causing the shaft to gradually crack and eventually completely break.
● The equipment and motor vibration are too large during operation. If the motor is not firmly fixed, such as running on the frame, the whole foundation is unstable, and the operation is swaying, which causes the tension of the motor belt to be unstable, and the tension is large and small, causing damage to the shaft.
● The shaft machining stress groove does not meet the requirements. This problem occurs mostly in the position of the root of the shaft. A large number of case studies can be found that the R angle of the root of the shaft is not standardized, resulting in a relatively concentrated stress at the position. The motor is subjected to axial and radial alternating stress during operation, resulting in fracture. .
● The crack at the welding position of the web shaft is broken. This is mainly for high-power motors. The welding process of the web will lead to stress concentration. The necessary measures should be taken during the manufacturing process, such as smoldering, vibration, processing, stress reduction and other measures to reduce or eliminate stress. If improper operation, Position is the biggest hidden danger of shaft breakage.