Cylindrical roller bearings adopt straight roller and parallel raceway configuration, featuring extreme pure radial load capacity and outstanding rigidity. Versions with single or double ribs can bear minor axial force. Separable inner and outer rings simplify disassembly, assembly and maintenance. They serve as core supporting bearings for industrial motors, heavy-duty gear reducers, hot rolling mills, gearboxes, air compressors, machine tool spindles and high-speed fan shafts. Four mainstream structures (NU rib-free, NJ single rib, NUP positioning, NF outer ring rib) are available for axial floating, axial positioning, high-speed operation and heavy rolling mill applications respectively.

Compared with spherical roller bearings, cylindrical roller bearings deliver higher limiting speed and lower rotational resistance for high-speed operation. Against tapered roller bearings, they possess stronger radial rigidity without tedious axial preload adjustment. The main limitation is nearly zero self-aligning capability, requiring high coaxiality and assembly precision of the shaft system. They are applied to transmission components with rigid shafts, precise alignment and demand for high speed or high rigidity bearing capacity.

High-power variable-frequency motors, large gear reducers and hot/cold rolling mills operate under high-speed rotation, continuous heavy load and instantaneous impact load. Inferior cylindrical roller bearings suffer large dimensional tolerance of rollers and insufficient rib hardness, leading to roller sliding, rib chipping and spalling under high speed, plus strip-shaped raceway wear. Consequences include excessive temperature rise at motor bearing seats, offset gear meshing clearance of reducers, excessive runout of mill rolls, abnormal equipment noise, oil leakage, gear tooth breakage and unqualified rolling accuracy, forcing production line speed reduction or shutdown maintenance.

NMT cylindrical roller bearings cover full series of NU, NJ, NUP, NF, N single-row, double-row and four-row types, including general single/double-row models for motors and reducers, and dedicated four-row heavy-duty models for rolling mills. High-purity carburized bearing steel is adopted overall. Raceways and rollers are processed by mirror superfinishing, while ribs are strengthened via high-frequency quenching for improved wear and impact resistance. Standard international dimensions enable direct replacement of imported cylindrical roller bearings for OEM motor assembly, reducer maintenance and overhaul renovation of metallurgical rolling mills.

High-end transmission equipment is upgraded toward high speed, miniaturization and high load density. Conventional cylindrical roller bearings have poor roller roundness, limited grease storage space for rapid lubricant depletion at high speed, and brittle ribs prone to chipping, failing to meet demands of 24-hour continuous high-speed operation of variable-frequency motors and alternating impact rolling of rolling mills. The market calls for cylindrical roller bearings with stable high-speed performance, tough wear-resistant ribs and precision-matched rollers.

NMT cylindrical rollers undergo graded selective grinding to unify outer diameter, length and roundness within micron tolerance for even force distribution during high-speed rotation and elimination of local sliding overheating. Mirror superfinishing for inner and outer raceways reduces friction coefficient and temperature rise for frequent start-stop of variable-frequency motors. NJ and NUP models feature thickened quenched-and-tempered axial ribs to balance hardness and toughness and resist fragmentation from axial float impact. NU rib-free design allows free thermal expansion of long motor shafts for thermal elongation compensation. Four-row cylindrical rollers are extended and thickened to double rated load for ultra-high rigidity support of hot and cold rolling rolls.

Two cage options are provided: stamped steel cages (cost-effective for general motors) and solid machined brass cages (for high-speed, high-temperature and heavy-load conditions). Oil storage grooves are added to cages for extended lubrication cycle on selected models. All finished bearings pass high-speed temperature rise test, radial rigidity load inspection and rib impact strength test to reject defective products with out-of-round rollers, insufficient rib hardness and clearance deviation, ensuring stable long-term operation under high-speed heavy-load conditions.

Core Product Advantages

Line-contact straight roller structure achieves maximum radial rigidity, with higher load capacity than ball bearings at equivalent volume for heavy-load high-strength support.

Multi-rib structural options: NU for axial floating, NJ for one-way positioning, NUP for bidirectional locking, satisfying both shaft positioning and thermal expansion compensation.

High-precision superfinished rollers and raceways deliver low friction and low temperature rise at high speed for continuous operation of variable-frequency motors.

Reinforced quenched axial ribs balance hardness and toughness to prevent rib damage and failure caused by axial impact.

Separable inner and outer rings simplify disassembly and overhaul to boost bearing replacement efficiency for reducers and gearboxes.

Custom double-row and four-row heavy-duty models provide ultra-high load and rigidity support for metallurgical rolling mill rolls.

Flexible cage selection: economical steel cages and high-temperature fatigue-resistant solid brass cages for high-speed scenarios.

Factory high-speed temperature rise and load testing prevents bearing seizure from overheating at high rotational speed.

Typical Application Scenarios

Main shaft bearings for Y/Y2/YVP variable-frequency three-phase asynchronous motors; planetary reducers, heavy-duty hard-tooth gearboxes, shield machine reduction boxes; four-row roll support for hot rolling mills, cold rolling mills and temper mills; high-speed transmission shafts of screw air compressors and centrifugal fans; precision spindles of CNC lathes and grinders; port winch gearboxes, large compressors, high-speed input ends of vertical cement mills.

Quality Assurance

NMT adopts exclusive precision finishing procedures for high-speed heavy-duty cylindrical roller bearings: vacuum forging of bearing steel blanks to reduce impurities and internal fatigue sources; through-feed centerless grinding and mirror superfinishing for rollers with dimensional grouping and matching; local high-frequency quenching and stress-relief tempering for axial ribs to avoid brittle fracture; high-speed dedicated C3/C4 enlarged clearance models to release thermal expansion stress at high rotational speed; preload matching for four-row rolling mill bearings to evenly distribute load across four rows. Delivered bearings feature smooth rotation and stable rigidity, resisting overheating at high speed and deformation under heavy load for round-the-clock continuous production of motors, reducers and metallurgical equipment.

Product Range

Single-row cylindrical roller bearings of NU, NJ, NUP, NF, N types; double-row cylindrical roller bearings, four-row rolling mill dedicated cylindrical roller bearings; stamped steel cages, solid machined brass cages; standard C0 clearance, high-speed dedicated C3/C4 enlarged clearance models.

Brand Strength

NMT NMT Japan addresses three typical failure modes of cylindrical roller bearings: overheating at high speed, axial rib fracture and eccentric roller wear. Upgrades of high-purity steel smelting, precision roller matching and toughening heat treatment for ribs greatly enhance high-speed stability, axial impact resistance and radial rigidity durability. It helps motor manufacturers, reducer maintenance service providers and metallurgical rolling enterprises cut bearing overheating faults and gear wear to guarantee high-speed stable production of transmission equipment.