No load and speed simulation is performed. Standard clearance is selected directly according to catalogs, with clearance reduction caused by motor temperature rise ignored, resulting in overheating and seizure during operation.

They know the motor is driven by a frequency converter but fail to warn of shaft current risks or offer insulated bearing solutions, which leads to washboard-like electrical erosion marks on raceways.

They are aware that the motor is driven by a frequency converter, yet do not alert to shaft current risks or supply insulated bearing solutions, causing washboard pattern electrical erosion on bearing raceways.

They adopt a one-size-fits-all grease filling approach, only using general-purpose grease without distinguishing continuous high-temperature, low-temperature start-stop and maintenance-free working scenarios, which leads to premature oil film failure.

They use generic sealing structures without customization based on motor internal negative pressure, moisture and dust environments, resulting in grease leakage and contaminant ingress.   

For alternating shock loads, they still adopt conventional processing for GCr15 steel, with no life margin design on materials and heat treatment.

They do not calculate the interference compression of shaft and housing bore, failing to account for clearance reduction after press fitting, which causes continuous temperature rise during operation.             

They only send replacement bearings after failure, without disassembly, failure analysis, or recommendations for grease, structure and corrective actions, so the same issue recurs repeatedly.