Cylindrical roller bearings are separable line-contact rolling bearings adopting straight roller and flat raceway structure. The inner and outer rings can be disassembled separately with ultra-high structural rigidity and outstanding radial load capacity. Classified into NU, NJ, NF, NUP, N types by rib structure, some models can bear unidirectional axial force. Featuring simple structure and excellent heat dissipation, they have outstanding limiting speed among heavy-duty roller bearings, serving as core supporting parts for high-speed industrial motors, heavy-duty reducers, metallurgical rolling mills, gearboxes, large air compressors and machine tool spindles.

Compared with spherical roller bearings, cylindrical roller bearings have higher raceway precision, lower running resistance and faster limiting speed for high-speed heavy-load equipment with guaranteed coaxiality. Different from tapered roller bearings, they focus on radial load bearing with lower heat generation at high speed, ideal for continuous motor operation. The limitation is strict requirement for shaft alignment, unable to compensate large shaft deflection or installation misalignment, not applicable for equipment with severe vibration and axis offset.

Metallurgical rollers, high-power industrial motors, heavy-duty gear reducers and large fans operate continuously with concentrated radial load, high rotating speed and cumulative heat. Bearings are required to have strong rigidity, high-speed stability, radial bearing capacity, heat dissipation performance and raceway wear resistance. Conventional cylindrical roller bearings suffer from inconsistent roller tolerance, rough raceway grinding, weak rib strength and unreasonable hardness gradient, easily causing roller eccentric load, rib breakage, raceway pitting and high-temperature seizure at high speed, resulting in excessive motor vibration, gearbox failure and poor rolling surface accuracy, leading to frequent shutdown and high maintenance cost.

NMT cylindrical roller bearings cover full series including NU, NJ, N, NF, NUP, RN single-row, double-row and four-row rolling mill dedicated models, equipped with stamped steel cages and solid brass cages for high-speed lightweight and heavy-shock working conditions respectively. Standard and C3 enlarged clearance are optional with general, P6 and P5 precision grades. International standard dimensions enable direct replacement of imported and domestic bearings for motors, reducers and metallurgical equipment.

With the upgrading of high-efficiency motors, compact high-torque reducers and high-speed rolling mills, traditional cylindrical roller bearings face defects including overheating at high speed, insufficient rigidity, easy rib fracture and short fatigue life, failing to meet continuous production demands. The industry needs precision cylindrical roller bearings with high rigidity, stable high-speed performance and strong fatigue resistance.

NMT adopts through double-end precision grinding for rollers to achieve micron-level cylindricity and dimensional grouping for even stress distribution without local overload loss. Superfinishing on inner and outer raceways reduces friction and temperature rise to avoid carbonization of lubricating grease. Reinforced fillet grinding and hardening on side ribs improve axial impact resistance to prevent rib cracking under axial load.

Structural optimization for different scenarios: high-speed motor version optimizes cage flow channel for enhanced lubrication circulation and heat dissipation to reduce wind resistance noise; rolling mill heavy-duty version thickens ring wall and widens roller contact surface to boost ultimate radial load. Separable structure allows independent replacement of inner or outer ring to cut spare part cost. High-purity carburizing bearing steel is adopted with forging to refine microstructure, balancing surface hardness for wear resistance and core toughness for impact fracture resistance.

All finished bearings pass radial runout inspection, roller matching, clearance sorting, high-speed temperature rise endurance test and axial impact test to eliminate defective products. Uniform rigidity and smooth operation avoid spindle runout and rapid clearance enlargement in long-term operation.

Core Product Advantages

Straight roller line-contact structure delivers strong radial load capacity and high rigidity to restrain spindle deformation and runout.

Micron roller grouping and raceway superfinishing reduce friction and heat for long-term operation of high-power high-speed motors.

Multi-rib structures (NU/NJ/NUP) realize axial positioning or free floating to meet diverse spindle limit requirements.

Hardened reinforced ribs resist axial impact to avoid rib chipping and fracture for extended service life.

Two cage options: stamped cage for low-noise high-speed use, solid brass cage for heavy impact working conditions.

Separable detachable structure supports single-component replacement for lower maintenance cost and easy assembly.

Gradient heat treatment on high-purity steel achieves surface wear resistance and core fracture resistance for both high-speed and heavy-load scenarios.

Complete product series with universal standard sizes for direct bearing replacement and convenient equipment renovation.

Typical Application Scenarios

Spindle support for high-power variable frequency motors, high-voltage motors and traction motors; high-speed and low-speed shafts of hard-tooth reducers, planetary reducers and gearboxes; hot & cold rolling mills, roller supports and roller conveyor equipment; large centrifugal fans, screw air compressors and turbine compressors; precision machine tool spindles, papermaking rollers, vertical cement mill transmission parts and marine reduction drive devices.

Quality Assurance

NMT implements full-process quality control for cylindrical roller bearings: raw bearing steel is inspected for oxygen content, metallographic structure and hardness; forgings undergo high-temperature stress relief annealing to eliminate internal stress and processing deformation. Segmented quenching and tempering after turning precisely control hardness gradient. Raceways, rollers and ribs are processed by precision grinding and superfinishing. Rollers are grouped in matched sets for balanced load distribution. Cages pass high-speed centrifugal and compression tests, and finished products receive full dynamic performance inspection. Delivered bearings feature stable rigidity, high-temperature resistance and impact resistance to guarantee continuous stable operation of power transmission and rolling equipment.

Product Range

NU, NJ, N, NF, NUP, RN single-row cylindrical roller bearings; double-row and four-row rolling mill special cylindrical roller bearings; stamped steel cages, solid brass cages; standard clearance, C3 clearance; general precision, P6, P5 precision grades.

Brand Strength

NMT focuses on R&D and production of precision heavy-duty roller bearings. Aiming at typical failures such as overheating vibration of high-speed motors, bearing fracture of reducers and insufficient rigidity of rolling mill bearings, NMT optimizes roller precision machining, raceway superfinishing, rib reinforcement structure and heat treatment formula to improve high-speed stability, structural rigidity and fatigue life of bearings. It helps industrial manufacturers reduce motor failure rate, reducer maintenance frequency and rolling mill consumable cost, improving equipment stability and production continuity.