One, the cause
The main reasons for shaft fracture are as follows:
① The motor vibrates strongly, and its dynamic load increases, or even overloads, causing the shaft to fatigue and break.
②Due to the step formed by the shaft diameter difference, the cross section of the shaft suddenly changes, or there is a keyway on the shaft, which causes stress concentration and fracture of the shaft.
③The motor starts frequently, or the starting speed is too fast, which causes the shaft to break.
④ The high carbon, silicon, and sulfur content of the shaft material will cause cracks or deformation during quenching and tempering, and increase the brittleness.
In addition, during the forging process, the internal defects of the shaft material, such as crystal segregation and carbide segregation, are not changed in shape, and they will expand and form cracks in the subsequent quenching and tempering, so that the strength of the shaft cannot reach the required strength. Breaks during operation.
2. Treatment method
① Countermeasures after the motor output shaft is severely broken outside the box: a new shaft must be replaced.
②The fracture depth of the motor output shaft outside the box does not exceed 10% of the shaft diameter. Emergency repair measures when spare parts are missing: Welding can be used, and continue to operate for a period of time after welding. Welding methods and technical requirements shall be implemented in accordance with relevant regulations.
③ Countermeasures when the motor high-speed shaft or Gear Shaft is broken: The shaft must be replaced with a new one.