Ningbo Kent Bearing Co., Ltd

Motor Bearing Selection: How Critical Is Load Calculation, Really? When selecting bearings, many motor manufacturers prioritize speed ratings and bore dimensions — yet consistently underestimate the decisive impact of load. A bearing's dynamic load rating directly determines the maximum combined load it can withstand, and the L10 theoretical life formula captures this relationship most clearly: bearing life is roughly inversely proportional to the cube of the applied load. Consider the numbers: the exact same bearing set can deliver 30,000 to 40,000 hours under light load conditions. But once it operates continuously near its rated load, service life collapses — raceway fatigue spalling can appear within just a few thousand hours. This is not manufacturing variance; it is fundamental physics. Three Load Types Every Motor Bearing Must Handle Motor bearings do not face radial loads alone. They endure a combination of radial, axial, and impact loads — each demanding careful evaluation. # Load Type Common Sources Consequence of Underestimation 1 Radial Load Belt pulleys, gears, eccentric rotors — the primary load in small and medium motors Excessive radial load causes raceway pitting and spalling; vibration progressively intensifies 2 Axial Load Fans, pumps, motors with significant axial float Standard deep groove ball bearings have limited axial capacity; excessive axial load demands angular contact bearings. Ignoring axial load leads to one-sided wear, abnormal noise, and overheating 3 Impact / Alternating Load Power tools, frequently started equipment with fluctuating loads Steady-state average load alone is insufficient for selection — a larger safety factor is essential, or alternating stress will accelerate fatigue damage Two Common Selection Pitfalls Pitfall 1 — Matching Bore Diameter Only: a standard bearing is selected based solely on shaft size, with zero load verification. The motor runs perfectly during no-load testing. But under real operating load, bearings fail with abnormal noise within a few hundred hours. Repeated replacements yield the same result — because the root cause was never addressed. Pitfall 2 — Oversizing "Just to Be Safe": selecting the highest load rating and largest bearing available, assuming more capacity is always better. Larger bearings bring increased mass, higher friction, elevated motor temperatures, greater energy consumption, and degraded NVH (noise, vibration, harshness) performance. The result is performance overkill paired with unnecessary cost. The Right Approach Effective bearing selection requires calculating actual combined loads — radial, axial, and dynamic — and matching them to the bearing's rated capacity with an appropriate safety factor tailored to the specific operating conditions. No single parameter can substitute for this analysis. About Kent Bearings With over 20 years of deep expertise in the bearing industry, Kent Bearings has developed distinctive product advantages through sustained investment in core technology. Compared to competitors, Kent products not only meet the stringent bearing requirements of diverse industries, but consistently address the most fundamental customer demand: bearing longevity.  

Many engineers, purchasers and equipment managers always have one lingering question in mind: how long can a bearing last under normal service conditions?   Many people hold misconceptions about bearing service life; a bearing is not considered failed only when it seizes up. In engineering applications, bearing failures fall into two categories: 1.Complete Failure The bearing seizes up and cannot rotate, completely losing its service function. 2.Performance Failure (Most Common) The bearing can still rotate, yet it suffers excessive vibration, increased noise, abnormal temperature rise and reduced precision, failing to meet the equipment’s design specifications.   The universally accepted industry judging criterion is clear: the theoretical service life of a bearing expires once the first fatigue spall emerges on its raceway or rolling element. However, actual on-site working conditions differ drastically from theoretical assumptions. Minor initial spalling on many bearings is barely detectable by naked eyes or monitoring instruments, and the bearings can still operate normally. Replacement is only mandated at a later stage when excessive vibration and abnormal temperature rise occur. Therefore, the usable lifespan of a bearing primarily depends on which replacement standard you adopt: High-precision equipment: Replace bearings at the first sign of initial fatigue spalling; General-purpose equipment: Replace bearings when vibration and temperature exceed limits; Rough-duty equipment: Keep running until bearing seizure. Setting aside complex calculation formulas, below are general industry reference values compiled in accordance with mechanical design handbooks and universal design standards from bearing manufacturers:   The standard design service life for bearings in ordinary small & medium industrial motors ranges from 20,000 to 40,000 operating hours. This serves as the universal benchmark for equipment type selection, structural design and quality verification. It must be emphasized that this figure is a design value under standard operating conditions, applicable to regular loads, rated rotational speeds, sufficient lubrication and clean environments.   Once subjected to overload, overspeed, dusty/humid surroundings, poor lubrication or mounting misalignment, the actual service life will be drastically shortened. Therefore, selecting the right bearings, maintaining proper lubrication and stabilizing operating conditions are the fundamental ways to extend bearing service life. Ningbo Kent Bearing boosts efficiency via automated production lines, controls quality with precision inspection systems, and aligns dual standards with international norms. We deliver consistently reliable bearings featuring high precision, low noise and long service life, making us a preferred supplier of medium-to-high end motor bearings.

When sudden disasters such as floodwater and impassable roads caused by typhoons strike, drones stand out as an aerial asset for emergency rescue, boasting unique strengths including high-altitude vision and rapid mobility.   As drones keep advancing toward lighter weight, longer flight endurance, higher maneuverability and operation under extreme working conditions, the performance requirements for their supporting components have risen drastically. Among these components, precision bearings—long regarded as basic fittings—have evolved from ordinary transmission parts into core essential components that enable drones to maintain steady flight, effective image stabilization, low noise and extended battery life. Unlike traditional mechanical equipment, drones rely on brushless motors, rotor transmissions, gimbal servos and swing structures to achieve high-speed, dynamic and multi-dimensional flight. Every instance of high-speed rotation, pitching movement, attitude adjustment, sudden stop and speed shift heavily hinges on bearings’ superior properties: low friction, high precision, lightweight design and strong vibration resistance. It can be said that a bearing’s precision, weight control, stability and fatigue resistance directly determine a drone’s flight stability, flight duration, anti-shake performance and overall service life. In contrast to overseas brands’ drawbacks of standardized mass production, long delivery cycles and high customization costs, domestic specialized, sophisticated, distinctive and innovative bearing manufacturers hold inherent strengths: flexible production lines, rapid customization response, efficient local supporting supply, outstanding cost performance and fast product iteration. Kent Bearing concentrates on ultra-precision machining capabilities, consistent heat treatment processes, lightweight structural R&D and long-term adaptation certification for complete drone aircraft. Compared with peer manufacturers, our products not only satisfy drones’ stringent demands for long endurance, high stability and low noise, but also deeply serve segmented application scenarios including consumer aerial photography, industrial inspection, agricultural plant protection & logistics, security surveillance and racing drones, delivering tailored non-standard customized solutions for diverse drone models.