Self Aligning Double Row Roller Bearing 23218 For Heavy Machinery / Energy Equipment

23218 Self-Aligning Roller Bearing For Heavy Machinery & Energy Equipment

In the complex field of mechanical engineering, the 23218 self-aligning roller bearing stands out as a key component with excellent performance. It is specifically designed to cope with harsh working conditions such as high loads and shaft deflection, and is widely used in various heavy-duty machinery, providing a solid guarantee for the stable operation of equipment.

I. Design and Structure

Inner Ring and Outer Ring

The inner ring of the 23218 bearing adopts a double-row raceway design, which precisely matches the shaft diameter of 90mm, ensuring no looseness after installation and achieving efficient force transmission. The outer ring is equipped with a spherical raceway, and this unique structure is the core of its self-aligning function. It can compensate for the installation deviation between the shaft and the bearing housing within a certain angle range (usually 1°~2.5°), greatly reducing the additional stress caused by poor alignment.

The outer diameter of the outer ring reaches 160mm, and the width is 52.4mm. The overall structure takes both load-carrying capacity and space adaptability into account. The thickened outer ring wall not only enhances the impact resistance but also provides more stable support for the raceway, making it suitable for long-term bearing of alternating loads.

Rolling Elements and Cage

The bearing uses double-row barrel-shaped rollers as rolling elements inside. Its curved surface design perfectly fits with the spherical raceway of the outer ring, and it can bear both radial loads and bidirectional axial loads. The rollers are made of high-strength bearing steel, which undergoes precision grinding, with a surface roughness controlled below Ra0.1μm, ensuring low friction characteristics during rolling.

The cage is usually made of brass, and the rollers are evenly separated through a segmented design. This structure not only ensures the free rotation space of the rollers but also can effectively guide the movement track of the rollers during high-speed operation, avoiding collision and wear between the rollers. For high-temperature or corrosive environments, steel or nylon cages can also be selected to meet different working conditions.

Sealing Structure (Optional)

Some models of 23218 bearings are equipped with contact or non-contact seals. The contact seal is made of nitrile rubber, which fits closely with the inner ring, and has excellent dustproof and waterproof effects, suitable for dusty and humid environments; the non-contact seal reduces friction through a labyrinth design, suitable for high-speed operation scenarios, and can adapt to a maximum speed of 3000rpm.

II. Key Parameters

III. Performance Advantages

Super Strong Load-Carrying Capacity

With the double-row roller design and optimized contact angle, the basic dynamic load rating of the 23218 bearing reaches 405kN, and the static load rating reaches 620kN, which can easily meet the high load requirements of heavy machinery. In applications such as crushers of mining machinery and rolls of metallurgical equipment, it can bear impact loads for a long time without fatigue failure.

Excellent Self-Aligning Ability

The cooperation between the spherical raceway of the outer ring and the barrel-shaped rollers enables it to automatically compensate for shaft deflection or installation deviation. In long-shaft equipment such as press rolls of paper machines and main shafts of wind turbines, this feature can significantly reduce the edge stress of the bearing and extend the service life by more than 30%.

Wear Resistance and High-Temperature Stability

The bearing rings and rollers are made of high-carbon chromium bearing steel (SUJ2). After quenching, the hardness reaches HRC60~65, and the surface is phosphated to enhance wear resistance. Within the temperature range of -40℃~120℃, its dimensional stability and mechanical properties remain stable, and specially heat-treated models can withstand temperatures above 200℃.

Low Friction and Vibration Suppression

Precision-machined raceways and rollers reduce contact friction, with a friction coefficient as low as 0.0015. At the same time, the double-row symmetrical structure makes the load distribution uniform, and the vibration velocity level can be controlled below 65dB during operation, which performs excellently in machine tool spindles and other equipment with high precision requirements.

IV. Material Quality

Material of Rings and Rollers

The main body is made of high-purity bearing steel (GCr15SiMn), and the vacuum degassing process is used to reduce internal pores and inclusions to ensure material density. The rollers undergo cold heading forming, high-temperature tempering and other processes, with uniform internal structure, impact toughness reaching more than 12J/cm², and significantly improved fatigue resistance.

Cage Material

• Brass Cage (H62): It has good thermal conductivity and strength, suitable for medium-high speed and heavy load working conditions, and can withstand temperatures below 150℃.

• Steel Cage (No. 10 Steel): After surface carburizing treatment, the hardness reaches HRC55~60, with strong impact resistance, suitable for occasions with severe vibration.

• Nylon Cage (PA66+GF30): Lightweight, low friction coefficient, good corrosion resistance, but the service temperature must be controlled below 120℃.

V. Application Fields

Heavy Industrial Machinery

In mining equipment, the 23218 bearing is used for the eccentric shaft of jaw crushers to bear huge crushing force and impact loads; in the metallurgical industry, it provides support for the work rolls of rolling mills, withstanding the double test of high temperature and rolling force.

Construction Machinery

The output shafts of gearboxes and slewing bearing parts of loaders and excavators widely use this bearing, and its anti-eccentric load capacity ensures the stable transmission of machinery when working on rough terrain. In the winches of cranes, the high load-carrying characteristics of the bearing ensure safety and reliability when lifting heavy objects.

Energy Equipment

The main shaft system of wind turbines relies on its self-aligning function to compensate for the shaft deflection caused by blade rotation, while bearing the radial and axial loads converted from wind energy. On the main shaft of water turbines in hydropower stations, the wear resistance of the bearing adapts to long-term operation in underwater or humid environments.

Papermaking and Textile Machinery

In the calender rolls and drying roll groups of large paper machines, the low vibration characteristics of the bearing ensure uniform pressing and drying of paper; the dyeing and finishing equipment in the textile industry uses its high-temperature resistance and corrosion resistance to maintain stable operation in a humid and hot environment.

VI. Installation and Maintenance

During installation, special tools (such as hydraulic nuts) must be used to ensure uniform force on the inner ring, avoiding deformation caused by knocking. For models with tapered inner rings, the clearance can be adjusted through the lock nut, and the recommended working clearance range is 0.12~0.25mm.

In terms of lubrication, for grease lubrication, extreme pressure lithium-based grease (NLGI Grade 2) should be selected, and the filling amount is 1/3~1/2 of the internal space of the bearing; oil lubrication is suitable for high-speed occasions, and it is recommended to use ISO VG 46 or 68 lubricating oil. When using forced lubrication, the oil pressure must be 0.1~0.3MPa.

Regular maintenance should check the bearing temperature (normally below 70℃), vibration value and abnormal noise, and replace it in time if any abnormality is found. A puller must be used during disassembly to avoid damage to the journal and bearing housing hole.

VII. Conclusion

With its high-strength design, excellent self-aligning ability and wide adaptability, the 23218 self-aligning roller bearing has become an ideal choice in the field of heavy machinery. Whether it is extreme loads, shaft deflection or complex environments, it can perform stably, providing solid support for the efficient operation of industrial production, and is an indispensable key component in modern mechanical engineering.