1. Design or manufacturing defects: There may be design or manufacturing defects that make the central shaft unable to bear the load or stress during normal operation of the coal mill. This may be due to the use of inappropriate materials, insufficient structural strength or errors in the manufacturing process.
2. Improper use or excessive load: During use, if the operator applies excessive load to the pulverizer or uses materials that exceed the design capacity of the pulverizer, the central shaft may not be able to bear this pressure and bend. Overload may also be due to the machine running for a long time without proper cooling.
3. Improper maintenance: Lack of proper maintenance may lead to problems with the central shaft. If the machine is not inspected and lubricated regularly, or special maintenance requirements are neglected, friction and wear may cause the central shaft to bend.