For electric motor production and R&D, whining noise is not only a notorious "quality saboteur" but also a top pain point for most motor manufacturers.

Drawing on decades of bearing technology expertise, I have identified that the root cause of the vast majority of motor whining noise issues lies in the selection and matching of bearings.

Fix 1: Choose High-Precision Bearings to Suppress Whining at the Source
One core cause of motor whining is insufficient bearing precision, which leads to excessively high friction-induced vibration frequencies between the raceways and steel balls during operation.Our high-precision ball bearings adopt nano-level super-finishing grinding technology, controlling radial runout within standard limits and significantly reducing vibration deviations during rotation. Coupled with an optimized raceway curvature design, they minimize high-frequency noise generated by frictional contact—cutting off the possibility of whining at the source. This is also the preferred solution for numerous motor manufacturers to resolve whining problems.
Fix 2: Match Low-Friction Quiet Bearings to Suit Diverse Working Conditions
Motors used in different application scenarios have varying bearing requirements; blindly using general-purpose bearings can easily trigger whining noise.For instance:
Home appliance motors demand silent operation;
Power tool motors need to withstand high-frequency start-stop cycles;
New energy motors require high-temperature resistance.
Our bearings are formulated with premium low-friction lubricants tailored to different motor working conditions. They not only reduce operational noise but also adapt to a wide temperature range of -20°C to 120°C. Furthermore, we offer customized adjustments based on customer-specific motor parameters such as power, rotational speed, and operating conditions, ensuring perfect compatibility between bearings and motors and eliminating whining caused by mismatched working conditions.
Fix 3: Strictly Control Bearing Installation & Quality Assurance to Avoid Secondary Whining
Even with the right bearings selected, improper installation or quality defects in the bearings themselves can still lead to whining noise.As a direct bearing manufacturer, every batch of our bearings undergoes 12 rigorous inspection procedures including dynamic noise testing and service life testing, ensuring zero quality defects before factory shipment. We also provide customers with professional installation guidelines to avoid issues such as coaxiality deviations and improper preload during assembly. This full-process support—from production to installation—helps manufacturers eliminate the risk of secondary whining noise.

In short, there’s no need to worry about solving motor whining noise—the core lies in selecting the right bearings, achieving precise matching, and enforcing strict quality control.

Ningbo Kent Bearing has provided over 200 million sets of silent bearing solutions to more than 500+ motor manufacturers worldwide.
If your motors are plagued by whining noise issues, or if you want to avoid such problems proactively, feel free to contact the Kenda Technical Service Team at +86-19957028916. We will provide you with a free customized technical bearing selection plan, helping you completely eliminate whining noise troubles and enhance your product competitiveness!