Cylindrical roller bearings adopt linear contact structure of cylindrical rollers and straight raceways, featuring strong radial rigidity and excellent limiting rotating speed. According to rib structure, it is divided into NU rib-free type, NJ single-side rib type, NUP bidirectional positioning type, N double-side rib type and other subtypes, realizing separable assembly of inner and outer rings to adapt to hot mounting process and axial limit assembly. Product structures include single-row, double-row and four-row types, with mainstream models including NU200, NU300, NJ200, NJ300 and NUP series; two configurations: open type, single/double-sided dust-proof sealed type, stamped steel cage and solid machined brass cage. It focuses on pure heavy radial load bearing, and single-side rib type can bear small unidirectional axial force, mostly used for transmission equipment requiring high-rigidity support, high-speed operation and precise axial positioning. Widely applied to hard-tooth-face reducers, high-power industrial motors, hot & cold rolling mills, screw air compressors, gear drive shafts, fan speed-increasing boxes and shield machine transmission components. Core strengths are strong rigidity against deformation, controllable temperature rise under high-speed conditions, separable structure for easy maintenance & replacement and outstanding radial load capacity.

Main model classification: NU series for free floating to compensate thermal elongation, NJ series for unidirectional axial positioning, NUP series for bidirectional axial locking, double-row NNU series for heavy-duty rolling mills; Precision grades: P0 general industrial grade, P6 motor precision grade, P5 high-precision grade for rolling mills; Clearance: C0 standard clearance, C3 enlarged clearance for thermal expansion of high-speed motors.

Performance comparison: Compared with spherical roller bearings, it has much higher limiting speed and stronger rigidity, yet no self-aligning capacity requiring strict coaxiality for shaft assembly. Compared with tapered roller bearings, it is suitable for continuous high-speed operation with lower heat generation yet weak axial load capacity unable to withstand strong axial impact force. Compared with deep groove ball bearings, radial load capacity increases several times with full rigidity & deformation resistance yet small axial floating allowance. Shortcoming: Obvious shaft deflection is prohibited; excessive coaxiality deviation directly causes edge stress cracking of rollers, and it can barely bear large axial load.

Industrial reducers, high-power motors and steel rolling production lines operate under harsh conditions including continuous high-speed operation, alternating radial load from gear meshing, thermal elongation of motor rotors, rolling impact of work rolls and temperature rise from high-speed shear of lubricating oil. Inferior cylindrical roller bearings suffer from large cylindricity deviation of rollers leading to sharp vibration surge during high-speed rotation. Shallow hardened layer of raceways causes fatigue pitting spalling under long-term cyclic load. Rough finish of ribs leads to rib wear & cracking under slight axial play. Insufficient cage strength causes cage fragmentation under high-speed centrifugal force, resulting in bearing seizure & bore sweeping, gear tooth breakage of reducers, motor burnout due to bore sweeping and uneven steel plate thickness caused by roll system runout of rolling mills, leading to production line shutdown.

NMT cylindrical roller bearings fully cover all structural series including NU, NJ, NUP, N and NNU, with sufficient stock for economical steel-cage bearings for reducers, brass-cage bearings for high-speed motors and four-row heavy-duty bearings for rolling mills. Made of electroslag remelting high-purity bearing steel, rollers undergo precision outer circle grinding with strictly controlled cylindricity tolerance for even load distribution along the whole roller row to avoid single-point overload. Superfinishing of raceways reduces friction coefficient to significantly lower heat generation during high-speed operation. Precision grinding of multi-rib structures forms smooth axial positioning end faces to resist wear from rotor axial thermal play. Standardized dimensional tolerance of separable inner & outer rings facilitates hot mounting assembly and direct replacement for old equipment without machining. Thickened double-row & four-row configurations are specially designed for continuous rolling heavy load of rolling mills, with integral rigidity to resist bending deformation of work rolls. High-speed dynamic balance inspection before delivery meets dynamic balance assembly standards for high-speed motors and speed-increasing boxes.

High-speed heavy-duty transmission and rolling equipment are upgraded toward higher speed, long-life maintenance-free operation and stable amplitude operation with high rigidity. Low-grade cylindrical roller bearings feature inaccurate cylindricity, thin wear-resistant raceway layer and fragile ribs, resulting in excessive vibration, enlarged clearance and bearing failure shutdown after short-term high-speed operation. The market is in urgent need of rigid cylindrical roller bearings with high-precision roller forming, superfinished raceways and high-strength limit ribs.

NMT realizes high-rigidity radial support, low-temperature-rise high-speed operation and precise axial anti-play limit via three core processes: precision cylindricity grinding of rollers, mirror superfinishing of raceways and reinforced forming of axial limit ribs. Finished bearings pass cylindricity inspection, high-speed temperature rise durability test, axial play wear resistance test and full-size sorting to eliminate defective products with roller deformation, insufficient raceway hardness and flawed ribs. It guarantees stable continuous operation of gear reducers, industrial main motors and steel rolling units, cutting costs from emergency shutdown maintenance and spare parts replacement.

Core Product Advantages

Linear contact support of cylindrical rollers delivers ultra-strong radial rigidity to restrain shaft bending deformation under heavy load for stable transmission precision.

Separable inner and outer rings eliminate overall shaft disassembly during maintenance of motors and reducers for efficient replacement.

NJ/NUP rib configurations realize unidirectional/bidirectional axial positioning to offset thermal axial play of motor rotors and protect gear end faces.

Precision cylindrical grinding of rollers reduces vibration during high-speed rotation, lowers lubricating oil consumption and controls temperature rise for long-term operation.

Optional two cage types: steel cage for conventional working conditions of reducers, solid brass cage for high-speed & high-temperature motors.

Reinforced double-row & four-row structures double load capacity under rolling heavy load of rolling mills to suppress work roll runout for guaranteed plate precision.

C3 enlarged clearance models are specially customized for high-speed motors to compensate high-temperature thermal expansion of main shafts and prevent internal bearing seizure.

Standard national standard overall dimensions support direct interchange of new and old equipment to match base seats of mainstream domestic & imported reducers and motors.

Typical Application Scenarios

Gear support bearings for hard-tooth-face planetary reducers, helical gear reducers and wind power speed-increasing boxes; Main shaft bearings for high-voltage high-power asynchronous motors, variable-frequency main motors and air compressors; Four-row cylindrical roller support bearings for hot strip rolling mills, cold rolling temper mills and four-high rolling mills; High-speed rotor bearings for screw air compressors and centrifugal compressors; Bearings for large centrifugal fan speed-increasing boxes and shield machine reduction transmission; Support bearings for metallurgical roller tables and continuous casting machine rolls.

Quality Assurance

NMT cylindrical roller bearings adopt integral quenching of electroslag remelting refined bearing steel + surface strengthening of raceways for high rigidity and excellent anti-fatigue spalling performance. Compatible with high-speed gear oil and high-temperature grease for motors, operating temperature ranges from -40℃ to 125℃, adapting to harsh industrial conditions such as low-temperature startup in winter, 24-hour continuous high-speed operation, rolling impact load and high temperature inside closed cavities.

Product Range

NU rib-free floating series, NJ single-side rib positioning series, NUP bidirectional locking series, N double-side rib limit series, NNU double-row heavy-duty rolling mill series; Structure: single-row cylindrical roller, double-row cylindrical roller, four-row cylindrical roller; Precision grades: P0 general industrial grade, P6 motor precision grade, P5 high-precision grade for rolling mills; Clearance: C0 standard clearance, C3 high-speed enlarged clearance; Sealing: open type, single/double-sided rubber dust-proof sealing; Cages: stamped steel cage, machined solid brass cage.

Brand Strength

NMT Japan solves three major pain points of ordinary cylindrical roller bearings: severe vibration caused by poor roller cylindricity under high speed, rapid wear of axial ribs and early pitting failure of raceways under heavy load. Core technologies including precision cylindrical machining of rollers, mirror superfinishing of raceways and structural reinforcement of limit ribs develop high-rigidity cylindrical roller bearings specially for reducers, high-power motors and rolling mills. We supply bearings for reducer manufacturers, motor OEMs, metallurgical steel rolling enterprises, air compressor manufacturers, industrial parts distributors and equipment operation & maintenance service providers to enhance rigidity and high-speed stability of transmission systems, extend bearing replacement cycle and reduce comprehensive operation & maintenance costs of industrial equipment.