1. Industry Working Condition Pain Points

In heavy equipment such as mining crushers, vibrating screens, metallurgical rolling mills, paper machinery and large fans, bearings face extremely harsh operating conditions. Long shafts inevitably deflect under their own weight and heavy loads; alignment between shafts and housing is difficult to achieve during installation; crushers and vibrating screens endure severe impact and vibration—the of these three adverse factors causes raceway crushing, cage fracture and early fatigue spalling in ordinary bearings under heavy impact, making them a regular failure.

 

Domestic spherical roller bearings, despite having some self-aligning capability, commonly suffer from insufficient roller crowning control, low spherical raceway grinding precision and weak cage strength. Under heavy loads, roller misalignment causes local stress concentration and large-area raceway pitting and spalling; under impact loads, cage deformation and fracture, as well as roller deflection wear, are frequent problems. Imported spherical roller bearings offer excellent performance but have long procurement cycles and high prices, making mass replacement cost-prohibitive.

 

In mining crushers, bearings endure enormous impact and severe vibration from ore, with raceway crushing often occurring within thousands of hours. In hot rolling mills, bearings operate continuously under the assault of high temperature, heavy loads and water vapor, with lubrication failure and early fatigue alternating. In vibrating screens, cages are fatigue-fractured under sustained high-frequency vibration. These harsh conditions urgently require professional spherical roller bearings with strong self-aligning capability, high load capacity, excellent impact resistance and resistance to high temperature and dust.

 

2. Product Core Positioning

Developed with Japanese heavy-duty bearing design experience, NMT spherical roller bearings focus on harsh conditions in mining, metallurgy and heavy machinery. With spherical raceways and barrel-shaped rollers as the core structure—the outer ring raceway is spherical and rollers are barrel-shaped—the bearing possesses excellent self-aligning capability, automatically compensating for shaft deflection and installation misalignment. Even when there is significant angular deviation between the shaft and housing, the bearing maintains uniform load distribution.

 

The double-row roller structure enables the bearing to simultaneously withstand radial loads and bidirectional axial loads, with load capacity far exceeding other bearing types of the same size. The precise coordination of spherical raceways and barrel-shaped rollers ensures uniform contact stress distribution across the raceway surface, with crowned rollers effectively eliminating edge stress concentration and greatly extending service life under heavy loads and impacts.

 

NMT has materials and heat treatment processes, employing gradient carburising—carbon concentration decreases smoothly from the surface inward, providing extremely high spalling resistance on the contact surface while the core maintains excellent toughness for absorbing impacts. By optimising the spherical radius of roller end faces, a more stable contact geometry is formed between rollers and rib flanges, enabling rollers to self-align under eccentric moments without leaving indentations on flange surfaces due to localised high pressure.

 

3. Structural Classification & Functional Advantages

(1) EA Series High-Capacity Type

 

Optimised internal design and roller profiles with maximised roller diameter and quantity, significantly increasing rated load capacity. Higher load capacity within the same installation space, suitable for heavy rolling mills, large crushers, ball mills and other equipment with extreme load capacity requirements.

 

(2) EM Series General-Purpose Type

 

Standard spherical roller bearings with balanced performance and wide applicability, suitable for general mining equipment, conveying machinery, fans, paper machinery and other conventional heavy-load conditions.

 

(3) Sealed Spherical Roller Bearing (WA Type)

 

With sealing structure to effectively block dust, moisture and corrosive media intrusion. Suitable for vibrating screens, crushers, outdoor conveyor equipment and other harsh environments with heavy dust and moisture, with sealed design extending maintenance cycles several times over.

 

(4) High-Temperature Spherical Roller Bearing

 

Special heat treatment and high-temperature grease adaptation for continuous operation at temperatures above 200°C. Suitable for hot rolling mills, drying equipment, sintering machines and other high-temperature conditions.

 

General advantages summary: Spherical raceways and barrel-shaped rollers provide self-aligning capability, compensating for shaft deflection and installation misalignment; double-row rollers carry radial and bidirectional axial combined loads; crowned rollers eliminate edge stress concentration; multiple cage options including machined brass and stamped steel; load-adaptive contact mechanism—smaller contact area for lower friction under light loads, automatic contact area increase to disperse stress under heavy loads.

 

4. Two-Grade Material & Process Selection

Grade 1: Through-Hardened Bearing Steel (General Version)

 

Integral quenching and low-temperature stabilizing tempering achieve uniform overall hardness with consistent raceway and roller wear resistance. Suitable for general mining conveyor equipment, fans, paper machinery and other continuous stable heavy-load conditions, with outstanding cost performance for complete machine supporting.

 

Grade 2: Carburized Bearing Steel (Heavy-Duty Reinforced Version)

 

Inner rings, outer rings and rollers undergo gradient carburising heat treatment—high carbon concentration on the surface forms an extremely hard wear-resistant layer, while low carbon concentration in the core maintains high toughness. Applied to crushers, vibrating screens, hot rolling mills, ball mills and other impact-type heavy-load conditions, withstanding instantaneous peak loads to prevent raceway crushing and roller fracture, with significantly extended service life under extreme conditions.

 

5. Japanese Precision Manufacturing Process

Vacuum degassing refining of high-purity special steel forging, controlling non-metallic inclusions to extremely low levels and eliminating fatigue crack initiation points;

 

Precision forging + gradient carburising heat treatment, with carbon concentration decreasing smoothly from surface inward, providing extremely high spalling resistance on the surface while the core maintains excellent toughness for absorbing impacts;

 

Spherical raceway ultra-precision grinding with precise spherical profile control, ensuring uniform load distribution between rollers and raceways across the full contact range;

 

Roller crowning machining—precise control of crowning profiles to optimise contact stress distribution and eliminate edge stress concentration;

 

Optimisation of roller end-face spherical radius—forming stable contact geometry between rollers and rib flanges, enabling self-alignment under eccentric moments;

 

Superfinishing grinding of inner and outer raceways for stable lubricating oil film formation;

 

Group matching of rollers with micron-level dimensional tolerance control for uniform load distribution;

 

Precision cage machining—machined brass cages or stamped steel cages available;

 

Assembly in temperature-controlled dust-free workshops, with four full inspections before delivery: load test, vibration test, clearance test and temperature rise test.

 

All dimensions comply with national standards for direct interchange with mainstream spherical roller bearings.

 

6. Seal Structure Matching for Working Conditions

Open Type : Maximum heat dissipation, suitable for high-speed fans, high-temperature rolling mills and other heavy-load applications requiring good cooling;

 

Single/Double-Sided Steel Dust Covers : Block large particle dust intrusion, suitable for mining conveyor equipment, general crushers and other dusty environments;

 

Rubber Contact Seals (WA Type) : Dust-proof, water-proof and corrosion media resistant, suitable for vibrating screens, outdoor crushers, metallurgical equipment with heavy moisture and other harsh environments.

 

7. Wide Application Fields

Mining Machinery: Cone crushers, jaw crusher main bearings, vibrating screens, ball mills, belt conveyor drums—withstanding enormous impact loads and severe vibration;

Metallurgical Equipment: Hot rolling mill work rolls and backup rolls, continuous casting machine roller tables, straighteners, sintering equipment—high-temperature heavy-load continuous operation;

Paper Machinery: Dryer cylinder bearings, press rolls, paper machine guide rolls—long-term reliable operation in high-temperature high-humidity environments;

Construction Machinery: Shield machine main bearings, large excavator slewing supports, concrete mixer trucks—heavy-load impact and harsh environments;

Fans & Ventilation Equipment: Large centrifugal fans, axial fans, high-temperature fan spindles—long-term continuous high-speed operation;

Cement & Building Materials Machinery: Vertical coal mills, rotary kilns, classifier spindles—dual challenges of heavy loads and high temperatures;

General Heavy Machinery: Large gearboxes, rubber and plastic machinery, marine propulsion systems.

 

8. Brand Supply & Customisation Service

NMT maintains sufficient spot inventory of mainstream spherical roller bearing specifications for urgent equipment repair and mass complete machine supporting with short lead time. Customisation services include special radial clearance (C2/C3/C4), high/low temperature resistant materials, special sealing solutions, special grease, non-standard sizes, EA high-capacity customisation, EM general-purpose configuration and more. Professional engineers provide targeted selection schemes based on equipment load spectrum, installation space, impact frequency and operating temperature to optimise bearing configuration, improve equipment reliability and durability under harsh conditions, extend maintenance intervals and cut the overall life cycle cost of equipment.