Ningbo Kent Bearing Co., Ltd

                                                                                                                                                                                                                                     Ningbo Kent Bearing has been deeply engaged in the bearing industry for over 20 years. With stable product quality, we have established long-term and stable cooperative relationships with more than 500 motor manufacturers at home and abroad. Recently, however, we encountered a    wave of product returns, which nearly damaged the brand reputation we have built up over the years.                                                                                                                                                                                                                                                                                                                  The cause of the incident is quite straightforward. At the end of April, we delivered a batch of motor bearings to one of our long-term cooperative motor manufacturers. However, merely three days after the goods arrived, the customer called us in a very angry and agitated tone, claiming that the batch of motor bearings had serious quality issues. After being installed on the production line, the bearings frequently suffered from overheating and jamming, and the customer demanded a full refund and return of the entire shipment.   After receiving the customer's feedback, we wre extremely confused. We have always followed strict standards and procedures for all motor bearings leaving our factory. Every process from production and manufacturing to finished product inspection is strictly controlled at every stage, and we have never had any batch quality issues over the years. To resolve the customer's problem as quickly as possible and prove the quality of our products, we immediately arranged a professional technical team to go to the site with testing equipment to investigate and trouble shoot the fault.   Upon arriving at the customer's factory, the technical staff of Kent Bearing immediately disassembled and inspected the faulty motors. After careful examination, it was found that the bearings operating abnormally with overheatinng and jamming issures were not at all the model and specification we supplied. We presented the inspection report of this batch of bearings to the customer, and gave a detailed expplanation of the correlation between bearing selection and motor performance.   After learning the whole truth of the matter, the customer withdrew the return application and also apologized to us. It turned out that the customer's warehouse had purchased bearings from multiple suppliers recently. Since most bearings are standard parts and look highly similar amount different manufacturers, the warehouse staff made an accidental mistake due to being overloaded and careless during the busy assembly process.            Although this misunderstanding was eventually resolved, it has sounded the alarm for all high-end motor manufacturers. High-end motors have extremely strict requirements on the precision and performance of bearings. As the core component of motors, bearings also act as the guardian of brand reputation. If your motors are troubled by bearing-related issues, or you want to avoid such problems in advance, welcome to contact the technical service team of Kent Bearing at 19957028916. We will help you quickly locate the root cause of problems, easily resolve motor failures, reduce after-sales losses, and steadily retain your core customers.     

“Deep groove ball bearings are the most widely used and highest-consumption core components in drones. Their performance directly determines flight stability, endurance and service life.”   Drones have core requirements for bearings: high speed, lightweight design, low friction and resistance to harsh environments. With their simple structure, strong adaptability and controllable cost, deep groove ball bearings have become the preferred choice for many key subsystems.   Deep groove ball bearings consist of an inner ring, an outer ring, steel balls and a cage. Their deep groove raceways can support both radial and slight axial loads simultaneously without the need for additional thrust bearings, meeting the lightweight requirements of drones. They are mainly used in brushless motors and rotor systems, and are also suitable for components such as small gimbals and steering gears.   As the "heart" of drones, brushless motors can reach tens of thousands of revolutions per minute. Most civilian drones use miniature deep groove ball bearings such as 5×11×4 mm and 8×22×7 mm, which are mounted in pairs at both ends of the motor shaft. Bearings of ABEC-5 precision or higher with 2RS/ZZ sealing are selected. For example, the 608 bearing (inner diameter 8 mm, P6 precision) has a limiting speed of 18,000 rpm and a dynamic load rating of 4.8 kN, making it a standard choice for motors in small civilian drones.   Consumer drone gimbals use even smaller miniature bearings, requiring low friction and low noise (≤20dB). Servos and control linkages adopt chrome steel (GCr15) bearings; after heat treatment, their hardness reaches HRC60–64, improving fatigue resistance.   Offshore operation drones adopt 440C stainless steel bearings for salt spray resistance, while industrial drones used in high-temperature environments are equipped with high-temperature resistant grease rated for -30℃ to +120℃.With outstanding cost performance, deep groove ball bearings have become indispensable basic components in the drone industry.   In summary, the core value of deep groove ball bearings lies in simplifying structure, improving efficiency and controlling costs. They are used across multiple drone systems. With the advancement of drone technology, these bearings are evolving toward higher precision, lighter weight and maintenance-free operation.      

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!