During product testing and feedback from field applications, we observed that Brushless DC diaphragm pumps exhibit significant abnormal noise under specific negative pressure conditions. Initially, this issue was often misdiagnosed as aerodynamic noise or assembly defects. However, a detailed analysis of the motor’s force dynamics revealed that the root cause lies in the destabilization of the "equilibrium point" between the pump’s compression load and the motor’s magnetic thrust at certain vacuum levels.
