Several problems affecting the reliability of switched reluctance motor
Switched reluctance motors have a particularly high starting torque and can achieve 3-6 times the rated torque. This is the advantage of the motor. However, if the design is not proper, the shaft breaking problem is easy to occur. When the switch reluctance motor was first applied in large quantities in China around 2005, the shaft breakage often occurred. In recent years, after continuous improvement by the research and development personnel, the problem of broken shaft has been basically solved.
This paper summarizes the reasons and measures for the motor broken shaft, in order to be taken for the future. The position of the broken shaft of the switched reluctance motor is basically concentrated on the root of the shaft, the root of the bearing, and the end of the web with the web shaft. Different positions and different crack paths have different reasons.
First, the motor is improperly assembled
The motor is not the same as the device being driven, causing the motor to withstand excessive radial loads, which ultimately 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 various directions of the shaft are deformed by the torsion force, and finally the motor shaft is broken, and the fracture position is generally close to the bearing.
For the motor with pulley connection, some customers give the motor output shaft with pulley. Because the pulley is too heavy or the belt is installed too tight, the motor output shaft will continue to be subjected to variable stress during the operation of the motor. The maximum bending moment of the shaft is near the fulcrum of the output shaft bearing. The repeated impact causes fatigue, causing the shaft to gradually crack, and finally completely breaks. The equipment and the motor vibrate excessively 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.
Second, the motor shaft processing stress tank is unqualified
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 the axial and radial alternating stress during operation, resulting in fracture. .
Third, the defects of the shaft design itself
If the diameter of the shaft is abrupt, it is also the cause of the breakage, but the problem is relatively small, and there are related requirements in the motor design specifications.
Figure 3 motor shaft
The load is too large, the small horse-drawn carriage, the motor shaft is in a state of fatigue for a long time, and the external force collision will also cause the broken shaft. The broken shaft is a relatively complicated problem. Both the motor manufacturer and the customer must pay attention to the problem. In order to avoid similar problems.
