Cylindrical roller bearings feature cylindrical roller rolling elements and rigid solid rib structure, divided into four basic structures: NU rib-free type, NJ single-side rib type, NUP positioning type and NF narrow rib type. The line-contact structure between rollers and raceways delivers strong radial rigidity and excellent limiting speed, enabling free axial floating or precise axial positioning. Focused on pure radial heavy-load and high-speed transmission scenarios, they serve as core supporting bearings for industrial reducers, high-power motors, rolling mill back-up rolls, gearboxes, air compressors and locomotive axles.

Main structural classification: NU type with rib-free inner ring for axial disassembly to facilitate hot mounting and disassembly of main shafts; NJ single-side rib type to bear unidirectional axial force; NUP combined rib type for bidirectional axial positioning; NF light rib type for medium & small power high-speed motors. Conventional models cover full size ranges of N2000, N3000, NU200, NU300, NJ200, NJ300, with multiple configurations including E reinforced rollers, EM machined brass cages, M brass cages and stamped steel cages.

Compared with deep groove ball bearings, radial load capacity is increased by more than 4 times with strong deformation resistance under heavy load and stable rigid support. Versus spherical roller bearings, the higher limiting speed suits continuous high-speed operation of motors and high-speed gearboxes. Unlike tapered roller bearings requiring paired installation, assembly is simpler with lower temperature rise. The main weakness is nearly no self-aligning capacity with strict requirements for mounting coaxiality; excessive shaft deflection will cause edge eccentric wear of rollers, making them unsuitable for equipment with eccentric deformation.

Heavy-duty gear reducers, high-voltage motors, hot & cold rolling mills and large air compressors operate under long-term high-speed rotation, alternating radial impact, elevated oil temperature and impurity-contaminated gear splash lubrication oil. Inferior cylindrical roller bearings suffer poor flatness on roller end faces and insufficient quenching hardness of ribs, leading to rib ablation caused by high-speed axial sliding friction. Inconsistent roller dimensions result in uneven load distribution and fragmentation from single-point overload. Insufficient cage strength causes cracking and disintegration under high-speed centrifugal force. Insufficient raceway surface finish leads to pitting spalling triggered by lubricant impurities, enlarged bearing clearance, sharp rise of reducer noise, excessive motor vibration, roll gap fluctuation of rolling mills and gear tooth breakage, resulting in overall scrapping of transmission components and high production line maintenance costs during shutdown.

NMT cylindrical roller bearings cover the full structural series of NU, NJ, NUP and NF, including standard type, E reinforced heavy-duty type and high-speed precision type with complete specifications of solid brass cages and stamped steel cages. Bearings are manufactured with vacuum arc remelting bearing steel. Super-mirror finishing grinding is applied on inner and outer ring raceways, and cylindrical rollers are precisely sized with dimensional tolerance controlled at micron level. Chamfering on both ends of rollers reduces axial friction stress. High-frequency local quenching strengthens axial ribs for outstanding high-temperature wear resistance. Clearance can be customized before delivery: C3/C4 large clearance for high-temperature working conditions of reducers and rolling mills, standard clearance for precision motors. Standard international mounting dimensions support direct replacement of various imported and domestic cylindrical roller bearings for integral gearbox assembly, motor maintenance and overhaul replacement of metallurgical rolling mills.

High-end gear transmission, variable-frequency high-speed motors and plate rolling mills are upgraded toward miniaturization, high power, long-duration continuous high-speed operation and high-temperature oil bath conditions. Conventional cylindrical roller bearings feature large dispersion of roller dimensional accuracy, poor high-temperature wear resistance of ribs and insufficient high-speed stability of cages. Long-term high-speed heavy load causes rib wear, roller fragmentation and raceway fatigue spalling, failing to meet low-noise and long-life operation requirements of precision transmission. The market demands precision cylindrical roller bearings with high dimensional accuracy, strong rigidity and excellent high-temperature wear resistance.

NMT cylindrical rollers are selected by grouping to unify roller height for even radial load distribution and eliminate breakage from single-point overload. Super-finished mirror raceways reduce turbulent flow resistance of lubricating oil to lower operating temperature rise. Thickened quenching strengthening on axial thrust ribs resists high-speed friction wear on roller end faces to avoid blue discoloration failure of ribs in high-temperature oil baths. Multiple cage options are available: cost-effective stamped steel cages for conventional reducers and air compressors; centrifugal-resistant and high-temperature-resistant solid brass cages for high-speed variable-frequency motors and rolling mill main shafts. E-type thickened roller structure improves overall load tonnage for low-speed heavy-duty gearboxes. Optimized raceway oil diversion structure ensures full lubrication on friction surfaces of rollers and ribs to reduce dry friction loss.

All finished bearings pass high-speed temperature rise test, roller dimensional grouping inspection, rib wear durability test and radial rigid load test to eliminate defective products with poor precision and insufficient rigidity, ensuring stable long-term operation of transmission equipment under high speed and heavy load.

Core Product Advantages

Cylindrical roller line-contact structure delivers ultra-high radial rigidity and load capacity, far exceeding ball bearings of the same size.

Optional multi-rib structures for free axial floating, unidirectional limit or bidirectional positioning to adapt to various main shaft structures.

Precision grouped roller matching realizes even load distribution to avoid fragmentation from local stress overload.

Mirror super-finished raceways reduce friction loss during high-speed operation for lower temperature rise and running noise.

Local strengthened quenching on ribs resists high-temperature friction on end faces with outstanding durability under impurity-contaminated gear oil conditions of reducers.

Dual cage options: brass cages for high-speed heavy load, stamped cages for general supporting to control costs.

Multiple clearance specifications available: C3/C4 large clearance for high-temperature equipment to compensate thermal expansion, standard clearance for precision motors to guarantee rotational accuracy.

Universal standard mounting dimensions enable direct replacement on old and new reducers, motors and roll bases without machining modification.

Typical Application Scenarios

Hardened surface reducers, planetary reducers, gearboxes, main shaft bearings for winch reduction equipment; rotor bearings for high-power variable-frequency motors, high-voltage motors, fan motors and air compressor motors; back-up roll bearings for hot rolling mills, cold rolling mills and temper mills; main shafts of screw air compressors and screw refrigeration hosts; railway locomotive axles, construction machinery gearboxes, large pump main shafts; paper machine roller shafts, cement vertical mill reduction boxes, marine gear transmission devices.

Quality Assurance

NMT precision cylindrical roller bearings adopt high-purity vacuum smelting bearing steel to reduce internal inclusions and delay fatigue pitting corrosion. Precision chamfering on both ends of cylindrical rollers cuts down cutting wear on ribs caused by roller edges during axial sliding. Stress relief annealing is conducted on all cages to prevent deformation and cracking under high-speed centrifugal force. Customizable end caps are available to adapt to oil bath lubrication and grease lubrication. Bearings are classified by clearance grade according to operating temperature before delivery: large clearance for high-temperature transmission equipment to offset thermal expansion seizure, standard clearance for constant-speed precision motors to secure rotational accuracy. The bearings are fully applicable to harsh industrial transmission conditions including high speed, heavy load, high-temperature oil bath and lubricating medium with impurities.

Product Range

NU rib-free floating type, NJ unidirectional positioning type, NUP bidirectional positioning type, NF narrow rib light-duty cylindrical roller bearings; E reinforced heavy-duty type, standard precision type; stamped steel cages, solid brass cages; standard clearance, C3 clearance, C4 large clearance models.

Brand Strength

NMT Japan solves three major defects of ordinary cylindrical roller bearings: roller fragmentation from uneven dimensional accuracy, rib ablation during high-speed operation and cage failure cracking under high-speed conditions. Process upgrades including precision roller grouping, rib strengthening heat treatment and raceway super-finishing enhance bearing radial rigidity, high-speed stability and high-temperature wear resistance. We supply high-precision long-life transmission bearings for reducer manufacturers, motor manufacturers and metallurgical rolling maintenance service providers, reducing failure rates such as abnormal reducer noise, motor overheating and rolling mill accuracy drift, cutting spare parts replacement frequency and shutdown maintenance costs of transmission systems.