NJ307EM Cylinder Roller Bearing 35x80x21 High Speed Roller Bearing

The NJ307EM cylindrical roller bearing is an indispensable component in mechanical engineering, enabling smooth mechanical operations, seamless power transmission, and stable equipment running. As a single-row cylindrical roller bearing, it features an inner diameter of 35mm, outer diameter of 80mm, and width of 21mm. This dimensional combination provides compactness with remarkable load-bearing capabilities, making it adaptable to diverse mechanical applications and operating conditions.

The NJ307EM bearing features precisely manufactured cylindrical rollers crafted from high-carbon chromium bearing steel through elaborate precision machining. The result is an extremely smooth surface with dimensional accuracy maintained within tight micrometer-level tolerance. The cylindrical shape allows for line contact with raceways, significantly enlarging the contact area compared to point-contact bearings. This design leads to more uniform load distribution, remarkably enhancing radial load-carrying capacity while effectively mitigating local wear and extending service life.

Both inner and outer ring raceways are processed using advanced super-finishing grinding techniques, achieving surface hardness of HRC60-65. This endows the raceways with excellent wear-resistance and fatigue-resistance properties. The geometric parameters are meticulously calculated to perfectly match the cylindrical rollers, ensuring smooth rolling within raceways while minimizing friction coefficient and reducing vibration and noise during operation.

The NJ307EM bearing typically uses an integral metal-machined cage made from high-strength alloy steel. The cage undergoes special heat treatment processes to enhance rigidity and toughness. With extremely high pocket size accuracy, it serves to accurately guide and separate cylindrical rollers, preventing collisions and friction. This ensures orderly roller arrangement even during high-speed operation, enhancing overall stability and extending service life. Some models with polyamide cages offer good self-lubrication properties and reduced operational noise.

The outer ring features double ribs while the inner ring has a single rib. This configuration provides certain axial load-carrying capacity, enabling the bearing to withstand one-way axial forces while performing axial positioning functions for shafts or housings. By restricting displacement in specific directions, the bearing operates stably even under combined loads, ensuring mechanical system reliability.

Due to line-contact design between cylindrical rollers and raceways, the NJ307EM bearing demonstrates outstanding radial load-carrying capacity. Its basic rated dynamic load reaches relatively high values, enabling it to handle substantial radial forces generated in heavy-duty machinery such as main shaft support systems of medium-sized industrial motors, precision machine tools, and various heavy-load transmission devices.

Although primarily designed for radial loads, the unique rib structure allows the NJ307EM bearing to withstand certain one-way axial loads. In working conditions with axial forces, it provides reliable axial positioning for equipment, ensuring normal operation under complex stress environments and enhancing overall mechanical system stability and reliability.

Engineered with precision processing technologies and optimized structural design, the NJ307EM bearing maintains stable performance even at high rotational speeds. Low-friction characteristics between rollers and raceways, combined with precise cage guidance, effectively reduce heat generation and vibration. This enables the bearing to meet high-speed, high-efficiency power transmission requirements in applications such as high-speed spindles in the machine tool industry. Limiting speeds reach approximately 11000-12000 rpm for oil lubrication and 7000-9000 rpm for grease lubrication.

Using high-quality materials and advanced manufacturing processes, the NJ307EM bearing shows excellent fatigue resistance. Under long-term full-load operation conditions, it effectively resists failures caused by material fatigue, significantly extending service life while reducing equipment maintenance frequency and minimizing downtime. This reliability is highly valued in industrial applications requiring continuous operation and high productivity.

Extensively used in various industrial machinery, particularly in transmission systems of automated production lines in manufacturing plants. It provides stable support for high-speed and high-load rotating shafts, ensuring smooth production line operation while reducing equipment failure risk and improving production efficiency.

Suitable for rotor support systems of medium-sized generators and turbines in the power generation industry. Operating under high-speed and high-load conditions, the NJ307EM bearing's ability to handle large radial loads and certain axial forces, combined with high-speed rotation stability, makes it an ideal choice for ensuring safe and reliable operation of power generation equipment.

Commonly used for spindle and feed shaft support of precision machine tools. The low-vibration and high-rigidity characteristics effectively reduce spindle run-out and vibration, guaranteeing dimensional accuracy and surface quality of machined workpieces. This improves overall machining efficiency and product quality in the machine tool industry.

Plays a crucial role in axle support systems of medium-duty trucks and construction machinery. Operating under harsh conditions with large loads and vibrations, the bearing's high load-carrying capacity, excellent fatigue resistance, and ability to withstand shock loads ensure safe and reliable operation while reducing maintenance costs and enhancing vehicle durability.

Proper lubrication is essential for maintaining performance and extending service life. Lubricant choice (grease or oil) should be based on specific operating conditions including temperature, speed, and load. High-temperature extreme-pressure grease is often recommended for high-load, elevated temperature applications. Before installation, ensure both bearing interior and installation area are thoroughly clean. Appropriate grease filling amount is typically 1/3 to 1/2 of the bearing's internal space. Regular inspections of lubrication state should be conducted, with timely replenishment or replacement to maintain optimal performance.

Establish a comprehensive regular inspection system for early detection of potential bearing problems. Conduct periodic visual inspections to check for cracks, rust, or abnormal wear on bearing surfaces. Use advanced monitoring tools such as vibration sensors and temperature monitors for continuous condition monitoring. Under normal circumstances, working temperature should not exceed 40°C above ambient temperature. If abnormal increases in vibration or temperature are detected, immediately shut down equipment for thorough inspection and necessary repairs or bearing replacements.

Maintain a clean installation environment to prevent dust and impurities from entering the bearing. Use specialized installation tools such as hydraulic presses and bearing installation sleeves to ensure proper installation without causing damage. Strictly avoid direct hammering on bearing outer or inner rings to prevent deformation and premature failure. Ensure bearing fit with shaft and housing meets design requirements precisely, with interference fit carefully controlled within specified range to prevent bearing slippage or over-tightening.

For NJ307EM bearings not in immediate use, proper storage conditions are crucial for maintaining quality and performance. Store in dry, well-ventilated areas free from corrosive gases, away from heat sources and high humidity. Place horizontally to avoid uneven stress and deformation from stacking. Wrap in anti-rust paper or plastic film to prevent rusting. Conduct regular checks during storage to ensure bearings remain in good condition.