1. Shaft breakage problem caused by misalignment
After the user’s equipment has been running for several months, the output shaft of the drive motor broke. Looking at its cross-section, it is similar to the output shaft of the (reducer), with the outer ring being bright and the axis core being dark, and finally the axis core broke. This indicates that the main cause of the shaft breakage is the misalignment of the assembly between the motor and the reducer.
When the concentricity is good, the output shaft of the motor only bears the rotational force and operates smoothly; when they are not concentric, the output shaft bears the radial force at the input end of the reducer. Under the long-term effect, it will bend, and the direction changes constantly with the rotation. The direction of the lateral force changes by 360 degrees every week. If the concentricity error is large, the radial force will cause the output shaft of the motor to heat up and the metal structure to be damaged. If it exceeds the bearing capacity, it will break. At the same time, this radial force may also deform or even break the input end of the reducer. Therefore, it is crucial to ensure the concentricity during assembly.
Intuitively, when they are concentric, the motor and the reducer fit tightly and the contact surfaces are connected; when they are not concentric, there is a gap. Similarly, the output shaft of the reducer can also break or bend for the same reason, and it is more likely to break due to greater output force. Pay attention to the concentricity of the output end during assembly when in use.
2. Shaft breakage problem caused by insufficient output of the reducer
In addition to poor assembly concentricity causing shaft breakage, the reasons for the breakage of the output shaft of the reducer also include:
1. Selection error, and the output of the matched reducer is insufficient. When selecting a type, one cannot only look at whether the rated output torque meets the working requirements. It is also necessary to consider that the product of the rated output torque of the motor and the reduction ratio should be less than the rated output torque of the similar reducer in the sample. At the same time, consider the overload capacity of the motor and the actual maximum working torque. The maximum working torque required by the user should be less than twice the rated output torque of the reducer. If there is a problem with the equipment installation, the output shaft and the load are stuck, and the motor is overloaded but still increases the output, which may cause the output shaft to bear a force exceeding twice the rated torque and break.
2. During acceleration and deceleration, if the instantaneous torque of the output shaft exceeds twice the rated value and occurs frequently, the shaft will also break. However, this situation is rare and will not be elaborated on.