What Is a Cylindrical Roller Bearing?

Cylindrical roller bearings are essential in industrial applications.They reduce friction and handle heavy radial loads. They also ensure the smooth operation of machines

This blog will explore the different types and key features of cylindrical roller bearings. The coverage will also include their applications. Additionally, it will provide tips on choosing and maintaining the right bearing for your needs.

Definition and Design

Cylindrical roller bearings are mechanical components used in rotating machinery. They are designed to reduce friction and support radial loads. They use cylindrical rollers that provide a larger contact area than ball bearings. This design makes them better suited for handling heavy radial loads.

Here’s a comparison between cylindrical roller bearings and ball bearings in a table format:

Key Components and Structure of Cylindrical Roller Bearings

Inner and Outer Rings

Inner Ring (Cone):

• The inner ring serves as the central component that fits onto the shaft or rotating part of the machinery.
• It provides stability by maintaining the positioning of the rolling elements (balls or rollers) relative to the shaft.
• The cone shape allows for an optimal fit and precise alignment with the rolling elements, ensuring smooth rotation.
• The inner ring helps distribute the radial load by transferring it from the rolling elements to the shaft. This prevents uneven wear and stress concentrations.

Outer Ring (Cup):

• The outer ring fits into the housing or stationary part of the machinery.
• It plays a critical role in holding the rolling elements in place and maintaining their correct alignment.
• The cup helps evenly distribute the load across the bearing. It provides a stable raceway for the rolling elements.
• It absorbs and spreads the radial forces exerted on the bearing. This ensures that the load is shared uniformly, reducing the risk of localized wear or damage.

Rollers and Cage

Role of Cylindrical Rollers:

• The cylindrical rollers are responsible for carrying the load in the bearing. Their shape allows for line contact with the raceways. This provides a larger contact area compared to ball bearings.
• This design enables the rollers to handle high radial loads efficiently without excessive deformation. The rollers transfer the load evenly across the bearing. This ensures stability and reduces the risk of damage because of concentrated forces.

Function of the Cage:

• The cage, often made of metal or plastic, holds the cylindrical rollers in place. It separates them evenly within the bearing.
• By keeping the rollers spaced apart, the cage prevents direct contact between them. This separation minimizes friction and wear between the rollers. It ensures smoother operation.
• The cage also helps prevent the rollers from skewing or misaligning. This prevents uneven load distribution and maintains bearing performance.

Cage Designs and Materials

Cages in cylindrical roller bearings are important for keeping the rollers in place. They prevent the rollers from touching each other and ensure smooth operation. The material of the cage affects how well the bearing performs in different conditions. Here's a simplified look at the common types of cages:

Steel Cages

• Strength: Steel cages are strong and durable, making them great for heavy-duty jobs.
• Heat Resistance: They can handle high temperatures, making them ideal for hot environments.
• Corrosion: Steel is susceptible to corrosion unless it is specifically made from stainless steel.
• Lubrication: Steel cages need proper lubrication to work well.

Brass Cages

• Wear Resistance: Brass lasts longer and reduces friction better than steel.
• Corrosion Resistance: Brass is less likely to rust, making it good for moist or wet conditions.
• Temperature: Brass works well in moderate to high temperatures.
• Smooth Operation: Brass cages help bearings run more smoothly and quietly.

Polyamide Resin (Nylon) Cages

• Lightweight: These cages are much lighter than steel or brass, which is good for applications like airplanes or high-speed machinery.
• Low Friction: Nylon cages reduce friction and often don't need extra lubrication.
• Chemical Resistance: Nylon is resistant to many chemicals but not as good at high temperatures.
• Quiet: Nylon cages produce less noise compared to metal cages.

Types of Cylindrical Roller Bearings

Design Features

Design Features:

• Single Row Cylindrical Roller Bearings: As the name suggests, these bearings feature one row of cylindrical rollers.
• Radial Load: They are designed to handle primarily radial loads (forces that act perpendicular to the shaft).
• Compact: The single-row design makes them compact and ideal for applications with space constraints. Single-Row Cylindrical Roller Bearings

Applications:

General Industrial Machinery:

• Uses: Single-row cylindrical roller bearings are commonly used in machines like pumps, compressors, conveyors, and gearboxes.
• Why: They are ideal for handling radial loads in machinery with moderate speeds. They also perform well under moderate to high load conditions.Their compact design also helps in optimizing space inside the equipment.

Electric Motors:

• Uses: These bearings are found in various types of electric motors, including small motors used in household appliances. They are also used in larger industrial motors.
• Why: Single-row cylindrical roller bearings help maintain smooth rotation in electric motors. They also minimize friction. They are particularly useful in motors with moderate speeds and moderate radial loads.

Double-Row Cylindrical Roller Bearings

Additional Radial Rigidity:

• Two Rows of Rollers: Double row cylindrical roller bearings have two rows of cylindrical rollers. This design helps distribute the load more evenly across the bearing. This helps improve the bearing's overall rigidity and makes it more capable of handling larger radial forces.
• Enhanced Stability: The dual-row design makes the bearing more stable. This helps prevent misalignment or distortion under heavy loads. Especially important in precision applications. Even small deviations can affect performance.
• Resistance to Deformation: The increased load capacity and rigidity make double-row bearings more durable. This makes them less likely to deform under high radial loads. This ensures that the bearing maintains its shape and functionality even in demanding conditions.

Full Complement Cylindrical Roller Bearings

Cage-less Design:

• No Cage: Unlike typical cylindrical roller bearings, full complement bearings do not use a cage. Instead, the rollers are in direct contact with each other. Instead, the rollers are packed closely together in a single row or multiple rows.
• Increased Roller Capacity: Without a cage, there is more room for the rollers. This increases the overall rolling element capacity of the bearing. This allows it to carry a higher radial load compared to bearings with a cage.

Benefits in Heavy-Load and High-Stress Environments:

• Higher Load Capacity: Without a cage, more rollers can fit into the bearing, increasing its load carrying capacity. This makes full complement cylindrical roller bearings perfect for handling heavy radial loads.
• Better Performance in High-Stress Conditions: Full complement bearings perform well in high-stress environments. They distribute the load uniformly across the rollers. This helps prevent roller damage, wear, or failure, even under tough conditions.
• Durability: These bearings are durable and can handle high radial loads and heavy shocks. This makes them perfect for heavy-duty machinery in industries like construction, mining, and steel manufacturing.

Multi-Row Cylindrical Roller Bearings

Key Features of Multi-Row Bearings:

• Multiple Rows of Rollers: Multi-row bearings consist of more than one row of cylindrical rollers, such as two or four rows. This design increases their load capacity compared to single-row bearings.
• Higher Load-Bearing Capacity: With multiple rows, these bearings spread the load evenly. This allows them to carry heavier forces without losing performance.

Applications in Rolling Mills and Heavy Machinery:

Rolling Mills:

• In rolling mills, steel and other metals are processed using multi-row bearings, especially four-row bearings. These bearings support the rolls, which are under extreme radial and axial loads. These bearings are built to handle the high forces involved in rolling and ensure the smooth operation of the mill.
• Multi-row bearings can handle both radial and axial loads, making them ideal for the back-up rolls in rolling mills. These rolls are subjected to heavy pressure from all sides.

Other Industrial Machinery:

Multi-row bearings are used in other industrial machines like crushers, presses, and conveyors. These machines handle heavy, continuous loads. The extra capacity of multi-row bearings is crucial for reliable performance. They have a high load capacity and are durable. This makes them ideal for applications where bearing failure can lead to costly downtime.

High-Capacity Cylindrical Roller Bearings

The combination of full complement and cage designs in high-capacity cylindrical roller bearings gives extra load capacity. It also provides high-speed performance:

• Extra Load Capacity: The full complement design provides increased load capacity. The cage ensures the bearing can still operate efficiently by keeping the rollers evenly spaced. This makes the bearing suitable for heavy-duty applications like industrial gearboxes and mining machinery. These applications often involve high radial loads.
• High-Speed Performance: The cage design reduces friction between the rollers. This allows the bearing to perform well at higher speeds. This is particularly important in applications like wind turbines. In these applications, bearings must operate smoothly at both low and high rotational speeds.

Applications:

• Wind Turbines: Bearings in wind turbines need to handle heavy loads and work efficiently at different speeds. The full complement and cage design provide the load capacity and speed performance needed for reliable operation.
• Industrial Gearboxes: Gearboxes often operate under high loads and speeds. High-capacity cylindrical roller bearings with both designs are perfect for ensuring smooth operation. They also handle the stresses encountered in these systems.
• Mining Machinery: Mining machinery, like crushers and mills, faces high radial loads. The full complement design increases load capacity. The cage design ensures smooth, high-speed operation. This helps the bearings perform reliably in tough environments.

Super-Precision Cylindrical Roller Bearings

Key Features:

• Tight Tolerances: Super-precision bearings are manufactured with extremely strict tolerances. This ensures minimal variations in size and shape.This helps reduce friction and wear, resulting in a smoother operation.
• High Rotational Accuracy: The bearings are designed to rotate at high speeds with minimal deviation. This ensures accuracy, even during fast operation. Industries like machine tools and automotive applications are especially important. In these industries, precision is of utmost importance.

Applications:

• Machine Tools: In machine tools, super-precision cylindrical roller bearings ensure high accuracy. They perform well during operations like milling, grinding, and turning. They let machines run at high speeds without losing precision. This makes them ideal for industries needing precise machining.
• High-Speed Automotive Applications: These bearings are also used in high-speed automotive applications. They are found in engine components and drivetrains. They handle high speeds while staying precise, ensuring smooth performance even in tough conditions.

Cylindrical Roller Thrust Bearings

Key Features and Functions:

• Axial Load Handling: Cylindrical roller thrust bearings are designed to carry axial loads in one direction. The cylindrical rollers align along the axis, helping them support these forces without bending. This makes them perfect for applications with heavy axial loads, like gearboxes or rotating shafts.
• Radial Load Support: These bearings can also support radial loads, in addition to axial loads. The roller design helps them handle side forces. This provides stability and reduces friction during operation.
• Efficient Load Distribution: The cylindrical rollers evenly distribute both radial and axial loads across the bearing surface. This helps the bearing handle heavy and continuous loads. As a result, it is reliable in tough machinery like gearboxes.

Applications:

• Gearboxes: Cylindrical roller thrust bearings are used in gearboxes to manage both axial and radial loads. This ensures smooth gear engagement and enhances the performance of the gearbox.
• Rotating Machinery: These bearings help maintain stability in rotating machinery by supporting both axial and radial forces. They are crucial for systems that experience both types of loads at the same time.

Key Benefits of Cylindrical Roller Bearings

High Radial Load Capacity

Cylindrical roller bearings are great for handling heavy radial loads. This is because they have a larger contact area than ball bearings. This helps spread the load more evenly, allowing them to carry more weight without wearing out quickly.

The design also makes them stiffer, reducing stress and friction, which means they last longer. These bearings are ideal for tough industries like mining and construction, where heavy loads are common.

Low Friction and High-Speed Capabilities

Cylindrical roller bearings have low friction because the rollers make line contact with the raceways. This helps them spin smoothly and quickly without creating too much heat. The reduced friction also reduce wear, making the bearings last longer and work better in high-speed situations.

Durability and Long Service Life

Cylindrical roller bearings, especially full complement designs, are resistant to fatigue. Using more rollers helps spread the load evenly, reducing stress and wear. This makes them last longer, even under heavy use, and makes them perfect for tough, long-lasting performance.

Versatility and Customization

Cylindrical roller bearings can be customized for different industries by adjusting the internal clearance and lubrication. The internal clearance is the small gap between the rollers and raceways. It can be made tighter for precise applications or larger for high-temperature environments.

Lubrication can also be customized. The right type of oil or grease helps reduce friction and keeps the bearing running smoothly. This customization helps ensure the bearings work well in different conditions, like in cars, airplanes, and heavy machinery. It makes them last longer and perform better.

Applications of Cylindrical Roller Bearings

Automotive Industry

• Wheel Hubs: Cylindrical roller bearings support the weight of the vehicle. They ensure smooth rotation by handling the high radial loads that occur during movement.
• Gearboxes: These bearings support the gears and shafts, allowing them to rotate efficiently. They absorb the high radial loads from the driving force.
• Axles: Cylindrical roller bearings spread the load evenly, which keeps everything stable and reduces friction. This is important for smooth and reliable performance under heavy loads.

Industrial Machinery

• Machine Tools: Cylindrical roller bearings are used in machine tools like lathes, mills, and grinders, where precision is key. They handle heavy radial loads and keep things rotating smoothly. This ensures accurate machining and prevents vibrations.
• Conveyor Systems: In conveyor systems, cylindrical roller bearings support the moving parts and handle heavy radial loads. They maintain stability and reduce friction. This ensures smooth movement of goods, even under heavy loads.
• Pumps: Cylindrical roller bearings in pumps support the rotor and shaft, handling radial loads for smooth operation. Their precision helps maintain efficiency. It also prevents wear, especially in high-speed or high-load environments.

Wind Turbines and Power Generation

Cylindrical roller bearings are used in wind turbine gearboxes to support heavy radial loads. They work reliably in tough environments, ensuring smooth operation. Their durability lasts even in extreme conditions like high wind speeds and changing loads.

Mining and Heavy Equipment

Cylindrical roller bearings are used in mining equipment and crushers to handle heavy loads. They provide stability and support under intense pressure, helping machines like crushers and mills run smoothly. These bearings can withstand shocks and vibrations in tough environments, making the equipment more reliable and longer-lasting. They help distribute the load evenly, reducing damage and the need for maintenance.

How to Choose the Right Cylindrical Roller Bearing

Assessing Load Requirements

Selecting the right bearing is crucial for ensuring smooth operation and extending the life of machinery. Here's a guide based on different load types:

• Radial Load: If the primary force is applied perpendicular to the bearing's axis, cylindrical roller bearings are ideal. They are designed to handle such radial loads efficiently. They are designed to handle heavy radial loads. These bearings are commonly used in applications such as motors, gearboxes, and wheel hubs.
• Axial Load: For forces applied along the bearing’s axis (like pressure on a shaft), consider thrust bearings. These bearings are designed to carry axial loads in one or both directions. They're commonly used in applications like gearboxes, turbines, and steering mechanisms.
• Combined Loads: In many cases, bearings need to handle both radial and axial loads simultaneously. For these, angular contact bearings or cylindrical roller thrust bearings are good choices. They can handle both types of loads effectively. Applications like gearboxes, pumps, and high-precision machinery often require bearings that can manage combined loads.

Importance of Matching Bearings to Load Requirements:

• Load Capacity: Each bearing type is designed to carry a certain amount of load. Selecting the wrong bearing can lead to premature failure.
• Performance: The right bearing ensures smooth and efficient performance under operating conditions. It helps reduce friction and wear.
• Longevity: Correctly matching bearings to load requirements reduces stress on the components. This leads to longer service life and fewer maintenance needs.

Speed and Rigidity Requirements

When choosing bearings for specific applications, speed and rigidity are two key factors to consider:

Speed Requirements: 

• For high-speed applications, choose bearings with low friction, such as ceramic or hybrid bearings. These types reduce heat buildup and allow smooth operation at faster speeds.
• Bearings with a higher precision grade, like super-precision bearings, are ideal for maintaining accuracy. They help minimize vibration at high speeds.

Rigidity Requirements:

• For applications requiring high rigidity, like machine tools, choose bearings with a higher load capacity. Cylindrical roller bearings are a good choice as they handle radial loads and provide the needed support for precision. They handle radial loads and provide the support needed for precision.
• In cases where additional stability is required, consider bearings with a larger contact area. Bearings with a full complement design offer higher rigidity under heavy loads.

Environmental and Maintenance Considerations

Here are some tips for selecting cylindrical roller bearings for applications with extreme temperatures, humidity, or dirty environments:

• Material Selection: Choose bearings made from materials like stainless steel or ceramic. These materials are more resistant to corrosion, rust, and extreme temperatures.
• Seals and Shields: Opt for bearings with seals or shields to prevent dirt, dust, or moisture from entering and damaging the internal components.
• Lubrication: Choose bearings with special lubrication that can handle high temperatures or humidity. Pick grease that works well in extreme temperatures and can resist moisture.
• High-Temperature Bearings: For high-temperature environments, choose bearings made to work well in heat. Look for those with ceramic or heat-resistant steel parts.
• Corrosion Resistance: In humid or wet environments, pick bearings made of corrosion-resistant materials. Look for those with special coatings or made from stainless steel for better durability.
• Maintenance Considerations: Ensure the bearings are easy to maintain and inspect, especially in dirty environments. Choose sealed or shielded options to reduce the frequency of maintenance.

Maintenance and Care of Cylindrical Roller Bearings

Regular Inspections and Monitoring

Regularly inspect bearings for wear, misalignment, and lubrication. This helps ensure they perform at their best and last longer.

Proper Lubrication

Using the right lubricant is key to how well a bearing works and how long it lasts. Grease is ideal for low-speed components. It effectively prevents dirt ingress and maintains its position for a longer duration.

Oil is better for fast or hot-running parts because it cools the bearing and reduces friction. Choosing the right lubricant helps the bearing work smoothly, reduces wear, and prevents overheating, making it last longer.

Bearing Replacement

• Monitor performance regularly: Listen for unusual noises like grinding or squeaking, and check for excessive vibration or heat. These could be signs that the bearing is wearing out.
• Check for wear: If there is visible damage, rust, or discoloration on the bearing, it may need replacement. Additionally, if it feels rough when turned by hand, it is time to replace it.
• Follow manufacturer recommendations: Manufacturers provide guidelines on bearing service life. Replacing them as recommended can help prevent unexpected failures.
• Replace during planned maintenance: Avoid waiting for a failure. Plan bearing replacement during regular maintenance cycles to reduce downtime.
• Use high-quality replacements: Always use the same type of bearing to ensure reliable performance. If necessary, choose a compatible alternative.

Conclusion

Cylindrical roller bearings are strong and can handle heavy loads. They reduce friction, helping machines run smoothly and last longer. They are reliable and need less maintenance, making them ideal for heavy-duty machines.

When choosing a cylindrical roller bearing, it's important to consider your specific needs. Think about the load, speed, and environmental conditions of your application. This will help you pick the right bearing to ensure smooth operation, longer service life, and optimal performance.

If you need help choosing the right bearing, feel free to contact LILY Bearing. We also offer custom solutions tailored to your specific needs. Our experts are ready to guide you in selecting the best bearings for your application.