Cylindrical Roller Bearings

Typical Materials:

Inner Ring

  • High Carbon Chromium Bearing Steel (GCr15 / AISI 52100 / 100Cr6)
  • Carburized Alloy Steel (20CrMnTi / SAE 8620)
  • Stainless Bearing Steel (AISI 440C)

Outer Ring

  • GCr15 / 100Cr6 Bearing Steel
  • Carburized Alloy Steel
  • Special Clean Steel (Vacuum Degassed Steel)

Cylindrical Rollers (Rolling Elements)

  • GCr15 Bearing Steel
  • Case-Hardened Alloy Steel
  • Ceramic (Si₃N₄ – Silicon Nitride)

Cage (Retainer)

  • Pressed Steel Cage
  • Machined Brass Cage
  • Polyamide (Nylon PA66 + Glass Fiber)
  • Machined Steel Cage

Flanges (Integrated in Ring Design)

  • Same as ring material (typically GCr15 or carburized alloy steel), heat-treated simultaneously.

Surface Treatments (Optional Enhancements)

  • Black Oxide Coating
  • Phosphate Coating
  • DLC (Diamond-Like Carbon) Coating

 

Are Cylindrical Roller Bearings Available in Sealed and Unsealed Versions?

Yes, Cylindrical Roller Bearings are available in both sealed and unsealed (open) designs, depending on application requirements, lubrication strategy, and operating environment.

1. Unsealed (Open-Type) Cylindrical Roller Bearings

Structural Characteristics

  • No integrated sealing components

  • Exposed rolling elements

  • Designed for oil or grease lubrication via external system

Performance Advantages

  • Higher permissible speed

  • Better heat dissipation

  • Suitable for oil circulation systems

  • Easier inspection and relubrication

Typical Applications

  • Industrial gearboxes

  • Large electric motors

  • Wind turbine gear systems

  • Machine tool spindles

  • Heavy transmission systems

Business Consideration

Open-type bearings are preferred when:

  • The housing already provides sealing

  • Continuous lubrication systems are used

  • High-speed performance is required

2. Sealed Cylindrical Roller Bearings

Structural Characteristics

  • Integrated contact or non-contact seals on one or both sides

  • Pre-filled with grease

  • Designed as maintenance-reduced or maintenance-free units

Seal Types

  • Rubber contact seals (2RS type)

  • Non-contact labyrinth seals

  • Metal shields (ZZ type)

Performance Advantages

  • Protection against dust and contaminants

  • Reduced grease leakage

  • Lower maintenance frequency

  • Improved reliability in harsh environments

Typical Applications

  • Agricultural machinery

  • Construction equipment

  • Conveyor systems

  • Pumps and compressors

  • Medium-duty industrial equipment

Business Consideration

Sealed versions are preferred when:

  • The operating environment is dusty or contaminated

  • Maintenance access is limited

  • Grease lubrication is sufficient

  • Moderate speed is acceptable

 
Recommended Lubrication Methods for Cylindrical Roller Bearings
1. Grease Lubrication
  • Select grease with appropriate base oil viscosity (typically ISO VG 100–220 for general industrial use)

  • Lithium-based grease is standard

  • For high temperature: Polyurea or synthetic grease

  • Avoid overfilling (30–50% internal free space recommended)

2. Oil Lubrication
  • Oil Bath Lubrication
  • Oil Splash Lubrication
  • Oil Circulation System
  • Oil-Air (Oil Mist) Lubrication
Industrial Application Recommendations

Electric Motors

→ Grease lubrication (Polyurea for long life)

Heavy Gearboxes

→ Oil bath or oil circulation

Wind Turbines

→ Oil circulation with filtration

Machine Tools

→ Oil-air lubrication

Pumps & Compressors

→ Grease (moderate duty) or oil (high duty)

Cylindrical roller bearing specifications primarily conform to ISO 15 standards, covering single-row (NU, NJ, NUP, N), double-row (NNU, NN), and four-row series. Core parameters include inner diameter (d), outer diameter (D), width (B), dynamic load (C), static load (Co), and limiting speed. These bearings feature high radial load capacity, and some designs allow for a certain degree of axial displacement or can withstand minor axial loads.

 

General parameter table for cylindrical roller bearings (partial typical dimensions)
Bearing model series inner diameterd(mm) outer diameterD(mm) widthB(mm) Main features
NU/NJ 200 10 – 100+ 30 – 200+ 9 – 40+ Light-duty series, high speed
NU/NJ 300 10 – 100+ 35 – 250+ 11 – 50+ Medium series, high radial load
NU/NJ 2200 20 – 100+ 47 – 215+ 14 – 58+ Wide-width, lightweight, high-rigidity
NNU / NN Specific query required Specific query required Specific query required Double-row, high-precision machine tool spindle

 

Key Specifications
  • Size Series: Follows ISO standards, e.g., diameter series 0, 2, 3, 4.
  • Tolerance Grade: Typically standard (CN/P0), high-precision applications can reach P6 or P5.
  • Axial Capacity: NU type without flange (cannot withstand axial force), NJ type with single flange (can be positioned in one direction), NUP type with flat retaining ring (can be positioned in two directions).
  • Cage Material: Typically steel or brass, polyamide (plastic) may be used for high-speed or specific applications.

 

The above data are typical industry parameters. Please consult us for detailed dimensions and rated loads for specific models.

 

  1. High Load Capacity
    Cylindrical roller bearings feature line contact between rolling elements and raceways, which allows them to support very high radial loads compared to ball bearings of similar size. This makes them ideal for heavy-duty machinery.

  2. Low Friction and High Efficiency
    The rollers reduce friction and heat generation, ensuring smooth operation and high mechanical efficiency, which is essential for equipment requiring continuous or high-speed operation.

  3. Rigidity and Precision
    These bearings provide excellent rigidity, maintaining shaft alignment under heavy radial loads. Their design also allows for high-precision positioning, which is critical in machine tools, motors, and precision equipment.

  4. Accommodates Axial Displacement
    Certain cylindrical roller bearing designs, especially single-row or double-row with floating capability, can accommodate axial displacement of the shaft, reducing stress on other components.

  5. Durable and Long Service Life
    Made with high-quality steel and advanced manufacturing processes, these bearings offer exceptional wear resistance and long operational life, minimizing maintenance frequency.

  6. Versatile Design Options
    Available in single-row, double-row, or multi-row designs, they can be tailored for different load capacities, speeds, and installation requirements, offering flexibility for various applications.

 

 

  • Heavy Machinery and Construction Equipment
    Perfect for cranes, excavators, and mining machinery that require high radial load support and reliability in harsh conditions.

推土机类型、部件及其用途:完整指南 | BigRentz                         在建造复杂工业建筑过程中进行的重型起重作业

 

  • Electric Motors and Generators
    Their low friction and high precision make them ideal for high-speed motor shafts and generator rotors.
博客 | WEG Motors — W22 系列,节能环保的理想之选

 

  • Gearboxes and Transmission Systems
    Cylindrical roller bearings can withstand heavy radial loads and shock loads, ensuring smooth operation in industrial gearboxes.

 

 

 

 

  • Machine Tools
    They provide high rigidity and accuracy, essential for lathes, milling machines, and CNC equipment.

 

 

 

 

  • Pumps, Compressors, and Fans
    Bearings ensure efficient rotation and long service life, even under continuous operation or varying load conditions.

 

 

VKUKEN has over 30 years of experience in bearing design and manufacturing. We can customize non-standard bearings according to customer drawings, or we can measure and create drawings of existing bearings on-site and then manufacture custom bearings based on those drawings. Our team of professional engineers has over 20 years of experience in bearing design and measurement.

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application engineer

Hi, I am Maxwell, I am an engineer in the field of bearing applications. I majored in mechanical and electromechanical engineering during college. After graduation, I worked for the top three "SKF" bearing companies in the world for ten years , during which I went to dozens of customers in different industries to help them solve problems in bearing applications; later I joined VKUKEN Bearing Manufacturing, and I will share bearing technical knowledge on this website from time to time. If you are a customer Please contact me to help you solve your problem; if you are also a technical expert in bearings, I am very willing to exchange technical knowledge about bearings with you.

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