Metallurgical rotary kilns, mining conveyor systems, large reducers, vibrating screens, crushers and wind turbine gearboxes are subjected to large radial loads and bidirectional axial loads simultaneously during operation. During installation, shaft alignment is difficult to achieve ideal precision, and during operation shafts deflect under load. Ordinary roller bearings lack self-aligning capability. Slight shaft misalignment causes unbalanced rolling element loading and localized raceway stress concentration, rapidly leading to early fatigue spalling and premature bearing failure. Most heavy equipment runs continuously year-round with fluctuating loads, persistent vibration and impact, placing extremely high demands on bearing vibration resistance, error tolerance and reliability.

 

Many heavy equipment installations operate in harsh environments with dust, high temperature and moisture. Lubrication maintenance cycles are long, and frequent shutdown for service is difficult. Conventional bearings lack self-aligning function and demand high alignment precision during installation. Minor assembly deviation drastically shortens bearing service life. Using multiple sets of bearings to share loads would greatly increase axial dimensions and structural complexity. The industry urgently requires heavy-duty bearings that can simultaneously withstand radial and axial combined loads, provide built-in misalignment compensation, and adapt to impact and vibration conditions.

 

NMT Precision Spherical Roller Bearings employ spherical rollers and double-row raceway structures, capable of withstanding large radial loads and bidirectional axial loads simultaneously. The spherical outer ring raceway provides excellent self-aligning performance. When shaft deflection exists, assembly coaxiality error occurs or bearing housing deformation takes place, the bearing automatically compensates angular deviation (allowable misalignment angle 1° to 2.5°), prevents one-sided overload of rolling elements and ensures uniform force distribution across all rollers. The symmetrical spherical roller design combined with spherical raceways achieves even load distribution, resists alternating loads, continuous vibration and instantaneous impact, suitable for long-term continuous heavy-duty operation.

 

Rollers are precision-machined from high-purity bearing alloy steel and sorted at micron level with superfinished surfaces to reduce friction coefficient. Shaft washers and housing washers undergo forging, precision grinding and superfinishing. All components receive carburizing quenching heat treatment and long-term low-temperature stabilization processing to achieve sufficient surface hardness with core toughness, balancing wear resistance and impact resistance. High-precision solid cages separate each roller accurately to avoid skew, mutual extrusion and collision. Optimized internal space stores grease steadily to extend maintenance intervals. Outer rings can be equipped with annular oil grooves and oil holes (W33 design) to improve lubrication effectiveness. Bores are available in cylindrical and tapered types (taper 1:12 or 1:30), allowing convenient mounting on plain or stepped shafts using adapter sleeves or withdrawal sleeves.

 

The bearings adopt international standard dimensions with excellent interchangeability. Imported counterparts can be directly replaced during maintenance and upgrading of existing equipment. Comprehensive specifications cover bore diameters from 20mm to over 1500mm, widely applied to metallurgical rotary kilns, mining conveyor systems, large reducers, vibrating screens, crushers, wind turbine gearboxes and various heavy industrial equipment. The bearings adapt to continuous rotation, load fluctuation, shaft deflection and alignment error coexistence conditions.

 

Core Product Advantages

Spherical rollers matched with spherical raceways simultaneously withstand radial loads and bidirectional axial loads, ideally suited for combined load conditions;

 

Spherical outer ring raceway features self-aligning function to compensate shaft tilt, assembly coaxiality errors and housing deformation, preventing premature failure caused by unbalanced roller load;

 

Symmetrical spherical roller design ensures even load distribution with high load limit, resisting alternating loads, continuous vibration and instantaneous impact loads;

 

Precision carburizing quenching heat treatment across all components provides high surface hardness with good core toughness, excellent wear and fatigue resistance under harsh high-temperature and dusty environments;

 

Optimized internal oil storage space retains grease persistently, extends maintenance cycles and cuts downtime;

 

Superfinished raceways matched with graded rollers reduce friction loss and heat generation for long-term continuous operation;

 

Integrated high-strength copper alloy or pressed steel cages limit roller movement accurately, suppress roller offset and jamming and improve running stability;

 

Cylindrical and tapered bore options with adapter sleeves or withdrawal sleeves enable convenient installation and removal;

 

Standard external dimensions ensure great versatility and convenient replacement to lower procurement costs of heavy machinery spare parts.

 

Typical Application Scenarios

Support devices for metallurgical rotary kilns, heavy-duty transmission equipment for smelting industry; large reduction units and gearbox support positions; mining conveyors, crushers and vibrating screen heavy-duty support units; wind turbine main shafts and gearboxes; building material vertical mills and heavy rolling equipment; paper machinery press rolls and large rubber machinery; construction machinery and port equipment slewing supports.

 

Quality Assurance

NMT Precision Spherical Roller Bearings are manufactured with premium refined bearing alloy steel. Incoming inspection includes chemical composition testing and metallurgical sampling inspection to eliminate material defects at source. Roller blanks are processed by precision rolling and cutting, followed by sequential rough grinding, finish grinding and superfinishing with strict control over roller spherical profile precision and surface roughness. Stress relief annealing is conducted after rough machining of shaft washer and housing washer forgings to eliminate internal stress, followed by carburizing quenching and low-temperature stabilization treatment to reduce dimensional variation risks under long-term heavy loads.

 

All rollers pass flaw detection screening to remove parts with cracks and dents. All components go through high-pressure cleaning and dust-free drying before assembly in clean workshops. Appropriate grease is filled according to practical working conditions. After assembly, finished bearings undergo combined load endurance testing, self-aligning simulation testing, impact load inspection and temperature rise testing. All unqualified products are eliminated completely to guarantee stable and consistent performance of bulk goods and supply reliable combined load bearing solutions for heavy industrial equipment.

 

Product Range

Spherical roller bearing standard series (21300, 22200, 22300, 23000, 23100, 23200, 23300, 23900, 24000, 24100 types); Cylindrical and tapered bore options; Copper alloy machined cages (CA type) and pressed steel cages (CC type, CD type); Selection is based on bore diameter, load rating and allowable misalignment angle.

 

Brand Strength

NMT focuses on R&D and manufacturing of heavy-duty spherical roller bearings. Targeting common industry challenges of combined loads, shaft deflection, continuous impact and harsh working environments existing in metallurgy, mining, wind power and building materials, NMT continuously optimizes spherical structure, roller profile and carburizing heat treatment technology. Through precise matching of spherical rollers and spherical raceways, the bearings effectively solve common defects of ordinary bearings such as lack of self-aligning capacity, severe partial abrasion and insufficient load capacity. NMT products reduce risks of sudden bearing damage on large heavy machinery, shorten maintenance downtime and support stable continuous operation of heavy industrial production lines. By optimizing the contact geometry between roller end faces and flange ribs, NMT enables rollers to automatically align when承受 eccentric moments, preventing local pressure marks on flange surfaces.