At both ends of high-speed motor rotors, cylindrical roller bearings support stable rotation at tens of thousands of rpm with extremely low friction. On heavy-load gearbox drive shafts, cylindrical roller bearings endure enormous radial loads and alternating stresses. In rolling mill work roll bearing housings, cylindrical roller bearings maintain precise roll gap control under alternating radiant heat from red-hot steel and cooling water. In wind turbine main shafts and gearboxes, cylindrical roller bearings maintain twenty-year maintenance-free continuous operation with extremely high reliability. Cylindrical roller bearings are among the most radially load-capable members of the rolling bearing family and the preferred bearing type for high-speed and heavy-load applications.

Cylindrical roller bearings are designated with type codes such as N, NU and NJ. Their defining feature is cylindrical rolling elements with line contact between rollers and raceways. Compared to the point contact of deep groove ball bearings, line contact multiplies radial load capacity. Meanwhile, cylindrical roller bearings have extremely low friction coefficients between rollers and raceways, maintaining low temperature rise even at high speeds. Another important characteristic of cylindrical roller bearings is separability——inner and outer rings can be installed separately, greatly facilitating assembly and maintenance of large equipment, particularly valued in gearboxes, rolling mills and other equipment requiring frequent servicing.

Based on roller guidance and rib configurations, cylindrical roller bearings are available in various types for different operating conditions: N type——outer ring without ribs, inner ring with double ribs, allowing axial displacement; NU type——inner ring without ribs, outer ring with double ribs, allowing axial displacement; NJ type——inner ring with single rib, outer ring with double ribs, capable of withstanding certain unidirectional axial loads; NUP type——inner ring with single rib plus snap ring, capable of withstanding bidirectional axial loads.

NMT Cylindrical Roller Bearing Technology Solutions

Japan NMT cylindrical roller bearings are specialized product series developed specifically for the stringent requirements of high-speed heavy-load equipment——high radial load capacity, low friction, long life and high reliability.

High-Capacity Structural Design——Cylindrical roller bearing radial load capacity depends on roller quantity, diameter and length. NMT cylindrical roller bearings feature optimized roller diameter and quantity, providing maximized radial load capacity within compact space. Rollers undergo precision crowning——roller generating lines feature logarithmic curve crowning eliminating edge stress concentration at roller ends, ensuring uniform load distribution along the full roller length, significantly extending bearing life under heavy loads. Bearing ring wall thickness is specially calculated to resist deformation under heavy loads. NMT cylindrical roller bearings are available in multiple configurations——N type, NU type, NJ type and NUP type, accommodating different axial load and positioning requirements, widely applied in various high-speed heavy-load equipment.

Precision Raceway Machining Technology——Cylindrical roller bearing operational precision and life directly depend on raceway machining precision and surface quality. NMT employs fully closed-loop controlled ultra-precision grinding systems for precision form grinding of raceways. Raceway roundness, cylindricity and surface roughness are strictly controlled to ensure uniform line contact between rollers and raceways at any position. Raceway surfaces undergo superfinishing with surface roughness controlled to extremely low levels, achieving mirror-like surface finishes that fundamentally reduce friction and temperature rise during operation. Rolling elements undergo precision screening and grouping with roller diameter deviation controlled to minimal ranges, ensuring uniform load distribution without localized overloading.

High-Speed Performance Optimization——Cylindrical roller bearings must maintain low heat generation and high stability at high speeds. NMT cylindrical roller bearings achieve high-speed performance through three approaches. Cage level——High-strength lightweight engineering plastic (PA66-GF or PEEK) or high-strength brass solid cages with precision dynamic balancing correction maintain precise roller guidance at high speeds, preventing collision and misalignment. Geometry level——Bearing internal geometry is optimized with precisely calculated roller diameter and length to minimize friction heat generation and churning losses at high speeds while maintaining load capacity. Lubrication level——Oil-air or oil-mist lubrication solutions are employed, with precisely controlled oil flow and air parameters to form stable oil films while removing internal heat. Validated through high-speed durability testing, NMT cylindrical roller bearings maintain stable performance with low vibration and low temperature rise under sustained high-speed operation.

Separability Design——The separability of inner and outer rings is a key advantage of cylindrical roller bearings in large equipment applications. NMT cylindrical roller bearing inner rings (with roller and cage assemblies) and outer rings can be installed separately——this characteristic greatly simplifies assembly processes during major maintenance of gearboxes, rolling mills and similar equipment, reducing installation difficulty and damage risks. Separability also facilitates bearing cleaning and inspection, allowing condition assessment during periodic maintenance without complete bearing disassembly.

Impact and Fatigue Resistant Design——Gearboxes, rolling mills and similar equipment generate impact loads during start-stop and load changes. NMT cylindrical roller bearing rolling elements and raceway materials undergo specialized heat treatment processes, achieving extremely high surface hardness while maintaining core toughness to effectively resist indentation and spalling under impact loads. Bearings undergo rigorous impact fatigue testing validation, maintaining stable rotational accuracy under simulated heavy-load gearbox and rolling mill impact cycles.

Long-Life Lubrication and Seal Design——Cylindrical roller bearing lubrication directly relates to bearing service life and maintenance intervals. NMT cylindrical roller bearings offer multiple lubrication solutions based on application requirements. Grease lubrication——Pre-filled with high-quality specialized grease, suitable for most general applications. Oil bath lubrication——Suitable for gearbox oil-lubricated environments, with oil circulating naturally during operation. Oil-air lubrication——Suitable for ultra-high-speed and heavy-load applications, precisely controlling oil-air ratios for optimal lubrication and cooling. For applications requiring sealing, NMT offers contact rubber seals or non-contact shields, effectively blocking external dust and moisture ingress.

Wide-Temperature-Range Adaptability——High-speed heavy-load equipment experiences large temperature variations from cold startup to hot operation. NMT cylindrical roller bearings utilize thermally stabilized materials and wide-temperature-range grease, maintaining dimensional stability and lubrication from -30°C to 150°C. Bearing clearance is precisely calculated with temperature compensation to maintain proper internal gaps across the full temperature range, preventing binding from thermal expansion or vibration from excessive clearance. For high-temperature applications, NMT offers specially thermally stabilized high-temperature cylindrical roller bearing solutions.

Comprehensive Product Portfolio——NMT provides diverse cylindrical roller bearing options for different operating conditions and equipment types. From 20mm to over 500mm outer diameter wide size coverage, from N/NU/NJ/NUP multiple configurations, from standard to C3/C4 special clearances, from stamped to brass solid cages, from open to sealed configurations, NMT cylindrical roller bearings are widely applied in various motors, gearboxes, rolling mills, fans, pumps, compressors, wind turbines, ship propulsion systems and other high-speed heavy-load equipment.

Why Choose NMT Cylindrical Roller Bearings?

Compared to conventional bearings and industry-standard cylindrical roller bearings, NMT cylindrical roller bearings offer distinct advantages:

• Optimized roller diameter/quantity/length for maximized radial load capacity

• Precision logarithmic curve roller crowning eliminating edge stress concentration

• N/NU/NJ/NUP multiple configurations for different axial load and positioning requirements

• Precision form-ground and superfinished raceways with mirror-like finish for low friction

• Lightweight engineering plastic/brass solid multiple cage options with precision dynamic balancing

• Optimized internal geometry for low friction and low heat at high speeds

• Oil-air/oil-mist/grease/oil-bath multiple lubrication options for different speeds and conditions

• Separable inner/outer ring design for convenient assembly and maintenance of large equipment

• Specialized heat treatment for high surface hardness + tough core, resisting impact indentation and spalling

• Thermally stabilized materials + wide-temperature grease for -30°C to 150°C stability

• C3/C4 clearance grade options for temperature compensation

• Open/sealed multiple configurations for different protection requirements

• Wide size coverage from 20mm to over 500mm outer diameter

• Passed high-speed durability, heavy-load life, impact and temperature rise testing

These performance advantages establish NMT cylindrical roller bearings as the core precision components for motors, gearboxes, rolling mills, fans, compressors, wind turbines and various high-speed heavy-load equipment.

Application Scenarios

Industrial motors and generators bearings

Heavy-load gearboxes and reducers bearings

Rolling mill work roll and backup roll bearings

Wind turbine main shaft and gearbox bearings

Ship propulsion system bearings

High-speed compressors and pumps bearings

Fans and ventilation equipment bearings

Railway vehicle axlebox bearings

Precision Manufacturing

Produced strictly according to ISO precision standards and cylindrical roller bearing manufacturing specifications, with zero-defect quality execution, NMT cylindrical roller bearings utilize high-purity bearing steel, processed through vacuum degassing treatment, precision heat treatment, raceway precision form grinding and superfinishing, precision rolling element crowning and screening/grouping, cage precision forming with dynamic balancing correction, optional seal precision assembly, specialized grease/oil lubrication configuration, rotational accuracy inspection, clearance grade precision control, high-speed durability testing, heavy-load life testing, impact testing and temperature rise testing. Every product is processed through fully automatic grinding and superfinishing in temperature-controlled clean workshops, with critical dimensional tolerances strictly controlled—ensuring high radial load capacity, high speed and long-life reliability.

Product Range

N-type cylindrical roller bearings (outer ring without ribs)

NU-type cylindrical roller bearings (inner ring without ribs)

NJ-type cylindrical roller bearings (inner ring with single rib)

NUP-type cylindrical roller bearings (inner ring with single rib + snap ring)

High-precision cylindrical roller bearings

High-speed cylindrical roller bearings

Custom non-standard cylindrical roller bearings

Global Industrial Service

Japan NMT supplies high-quality cylindrical roller bearings to global motor manufacturers, gearbox producers, metallurgical equipment suppliers and the wind power industry. With high-radial-capacity precision engineering and long-term stable reliable performance, NMT continuously empowers the efficiency and reliability of global high-speed heavy-load drive equipment.