Tapered roller bearings feature a matched tapered structure composed of tapered rollers, tapered inner ring raceways and tapered outer ring raceways, which are separable bearings. The inner assembly (inner ring + rollers + cage) and outer ring can be disassembled separately. Its core advantage is to bear huge radial load and unidirectional axial load simultaneously, which can effectively restrain axial play of transmission shafts. It is the key supporting bearing for axle transmission, gear reducers, steel rolling equipment, heavy load loaders and mine wheel reducers. Through force conduction on the tapered inclined surface, axial force can be evenly distributed to the entire raceway to avoid stress concentration at a single axial point, adapting to working conditions such as axial thrust from gear meshing, axial impact during vehicle start and brake, and axial jacking force of rolling rolls during rolling.

NMT tapered roller bearings have a complete product line, covering standard single-row models such as 32000, 32200, 32900, 30200, 30300, double-row 352000, 351100 series, four-row tapered roller bearings specially for rolling mills. We also provide inch-size non-standard tapered roller bearings, thickened reinforced heavy-duty models and oil-sealed dust-proof models. Standard metric models are available for immediate delivery, and non-standard customized replacement can be made according to original axle drawings, rolling mill dimensions and reducer shaft end sizes to meet maintenance replacement of old and new bearings for commercial vehicles, construction machinery, metallurgical rolling and heavy mining equipment. Two cage types are available: stamped steel cage for conventional vehicle impact conditions and solid brass cage for stable operation of high-temperature low-speed rolling mills and large heavy-duty reducers.

Compared with cylindrical roller bearings and deep groove ball bearings, the prominent advantage of NMT tapered roller bearings is the combined radial and axial load capacity. During the operation of gear reducers, helical gears and spiral bevel gears will generate continuous axial component force. Ordinary bearings cannot offset axial thrust, resulting in axial displacement of gears, eccentric wear of tooth surfaces and extrusion damage of oil seals leading to oil leakage. When heavy-duty truck rear axles and wheel reducers experience rapid acceleration, braking and steering, half shafts will produce strong axial impact, which easily causes axial ring detachment and bearing collapse for ordinary bearings. The tapered raceway inclined structure of NMT can directly bear axial force. Combined with precise adjustment of assembly clearance, the axial position of the shaft is firmly locked to ensure axial positioning accuracy of gears, half shafts and work rolls. Compared with angular contact ball bearings, roller line contact bearing capacity is several times higher, delivering far better stability under heavy impact conditions.

Heavy-duty truck rear axles, passenger car differentials, loader wheel reducers, bulldozer gearboxes, hot and cold rolling mills, wire rod rolls, large gear reducers, coal mine scraper drive ends, tower crane slewing supports and agricultural heavy tractor axles operate under alternating axial impact, bump vibration, mud splashing, high oil temperature and heavy load start-stop all year round. Low-end inferior tapered roller bearings commonly suffer from taper angle deviation of rollers, rough machining of tapered raceways, insufficient heat treatment hardness, plastic deformation of rollers under heavy load, fracture of cage rivets, mud infiltration without protection leading to raceway corrosion. During service period, rapid increase of axial clearance, excessive play of transmission shaft, abnormal gear knocking noise, bearing overheating seizure and roller fragmentation jamming will occur, causing vehicle breakdown on the road or emergency shutdown of production lines, resulting in high emergency maintenance costs and production loss.

All NMT tapered roller bearings are made of vacuum degassed bearing alloy steel with strictly controlled impurities. Grain refinement annealing is carried out after forging to improve steel toughness and resist fatigue cracking caused by alternating load. Tapered raceways of inner and outer rings are processed by forming grinding and ultra-precision grinding to ensure minimal taper angle matching error. Rollers adopt precise taper crowning modification to realize even load at both large and small ends and prevent crushing failure caused by overload on one end of rollers. Deep hardening is applied on raceway surface to achieve high surface hardness for wear and pitting resistance, while the bearing matrix core retains high toughness to avoid brittle fracture under vehicle bump and high-pressure impact of rolling mills. The separable split structure facilitates on-site maintenance; the outer ring or inner core assembly can be replaced separately without complete disassembly of the transmission shaft to shorten maintenance time.

Two sealing options are available: open type for oil bath lubrication of gearboxes, where lubricating oil directly infiltrates raceways for heat dissipation, suitable for continuous high-temperature operation of rolling mills and large reducers; single/double-side rubber oil seal type blocks mud, sand and dust from road surface invading the bearing cavity, adapted to open-air driving operation of trucks, loaders and construction machinery to prevent raceway corrosion and pitting failure.

Cage matching for different scenarios: cold-rolled steel stamped riveted cage features good toughness and vibration impact resistance for commercial vehicle axles and construction machinery traveling mechanisms; integral brass machined cage boasts strong structural rigidity, high temperature resistance and deformation resistance for long-term stable heavy-load operation of hot rolling mills and large industrial reducers.

Every NMT tapered roller bearing undergoes a full set of precision inspections before delivery: taper angle coaxiality inspection, roller dimension sorting, raceway hardness flaw detection, axial load fatigue test, sealed waterproof spray test and clearance grouping calibration. Standard assembly clearance is reserved for finished products, and clearance fine-tuning with gaskets is supported to meet demands of different loads and rotating speeds. Operating temperature ranges from -30℃ to 170℃, compatible with gear oil, extreme pressure grease, circulating lubricating oil and other lubricating media.

Heavy trucks, construction equipment and steel rolling units equipped with NMT tapered roller bearings maintain stable axial clearance of transmission shafts for a long time without play and abnormal noise. Rear axle gears mesh smoothly to reduce gear wear; accurate axial positioning of rolling mill rolls ensures uniform steel plate rolling thickness and eliminates rolling defects caused by axial shifting; no axial displacement of reducer main shaft avoids frequent damage and oil leakage of box oil seals, greatly reducing overall equipment failure rate. The service life of bearings is more than 2.5 times longer than that of low-end miscellaneous bearings.

With the upgrading of commercial vehicles, metallurgical rolling mills and heavy construction machinery towards large tonnage, high torque and intensive continuous operation, inferior tapered roller bearings have insufficient axial bearing capacity, fast taper surface wear and easy water corrosion, only applicable for short-term temporary use. Frequent disassembly and replacement of axles and transmission components consume massive labor and material resources. Relying on four core technologies including high-precision taper surface grinding, tapered roller load equalization crowning, purified bearing steel heat treatment and split convenient assembly, NMT solves common industrial failures such as sharp increase of bearing axial clearance, roller crushing and fragmentation, mud corrosion, high-temperature fatigue failure and axial positioning failure, providing long-term reliable transmission bearing supporting solutions for heavy trucks, construction machinery, metallurgical rolling mills and industrial reducers.

Core Product Advantages

Split separable structure enables separate disassembly of inner core and outer ring for convenient equipment maintenance and replacement to shorten maintenance duration.

Tapered raceway composite bearing capacity withstands large radial force and unidirectional axial force simultaneously to restrict axial shifting of shafts.

High-precision taper angle matching and roller crowning realize uniform load distribution to avoid deformation and fragmentation caused by unilateral compression of rollers.

Deep heat treatment of high-purity bearing alloy steel achieves wear and pitting resistance on surface and impact fracture resistance at core.

Two cage selections: stamped steel for vehicle impact conditions and solid brass for high-temperature industrial heavy-load scenarios.

Optional oil seal structure delivers effective waterproof, mud-proof and dust-proof performance to prevent bearing corrosion for outdoor traveling equipment.

Full-size metric spot goods + inch non-standard customization for replacement of imported axles, old rolling mills and imported reducers.

Pre-delivery precision clearance calibration supports gasket fine-tuning of assembly clearance to adapt to different torque and rotating speed scenarios.

Typical Application Scenarios

Commercial vehicles: heavy-duty truck rear axle, semi-trailer axle, passenger car differential, pickup drive axle, gearbox output shaft;

Construction machinery: loader wheel reducer, bulldozer gearbox, excavator travel motor, road roller hub;

Metallurgical rolling equipment: hot rolling mill, cold rolling roll, wire rod mill, bar mill four-row tapered main bearing;

Industrial transmission equipment: large hard-tooth surface reducer, bucket wheel stacker-reclaimer, tower crane slewing reducer, belt conveyor roller shaft end;

Agricultural heavy equipment: high-horsepower tractor rear axle, harvester drive shaft, agricultural grader transmission bearing.

Quality Assurance

NMT tapered roller bearings adopt vacuum refined bearing alloy steel raw materials, precision turning after forging forming, double precision grinding for tapered raceways and gradient quenching for heat treatment to form mechanical structure with hard outer layer and tough inner core. Pre-rotation running-in is conducted after assembly to release assembly stress, and full inspections of taper precision, load fatigue and sealing performance are completed before delivery. The products adapt to harsh working conditions such as heavy impact, mud erosion, alternating high and low temperature and continuous torque transmission, reduce unplanned vehicle breakdown and unexpected shutdown of industrial production lines, cut bearing spare parts reserve and maintenance labor cost to significantly lower comprehensive operating expenses.

Product Range

Single row tapered roller bearings: 30200, 30300, 32000, 32200, 32900 series metric bearings, inch-size non-standard tapered bearings;

Multi-row structure: double row tapered roller bearing 352000 series, four-row tapered roller bearing specially for rolling mills;

Sealing types: open type without seal, single-side oil seal, double-side oil seal;

Cage types: stamped riveted steel cage, integral brass machined cage;

Features: combined axial-radial load bearing, detachable assembly, adjustable clearance, impact resistance, optional waterproof and dustproof performance.

Brand Strength

NMT Japan has long-term experience in R&D and manufacturing of heavy-duty transmission tapered roller bearings, focusing on targeted optimization and improvement of tapered bearings for commercial vehicle axles, construction machinery and metallurgical rolling mills. Continuous process upgrading is carried out to eliminate defects of mainstream products such as poor taper precision, insufficient axial bearing capacity, water ingress corrosion, cage fracture by vibration and rapid raceway wear. Supported by core technologies of ultra-precision machining of tapered raceways, roller load equalization design, gradient toughness heat treatment and split modular structure, NMT develops tapered roller bearings with high axial rigidity, impact resistance, mud resistance and long service life. Bulk supply is provided for complete vehicle manufacturers, construction machinery maintenance stations, steel rolling enterprises and transmission equipment parts distributors to stabilize the operation of transmission systems, eliminate abnormal transmission noise and axial play failures, reduce emergency shutdown maintenance, help enterprises stabilize operation and reduce comprehensive post-maintenance costs.