NMT Ltd.
Corporate Communications Department
NMT Spherical Roller Bearings for Conveyor Pulleys, Dustproof Shock-Resistant Heavy Load Bearings for Mining Belt Conveyor Head & Tail Pulleys
1. Failure Analysis of Spherical Roller Bearings for Conveyor Pulleys
Belt conveyors are essential continuous conveying equipment for coal mines, aggregate plants, ports, power plants and cement factories. The head drive pulley, tail tension pulley and bend pulley are supported by spherical roller bearings. Ordinary bearings suffer frequent failures under assembly coaxial deviation, unbalanced belt tension, heavy dust, open-air rain and mud erosion, startup impact load: roller edge breakage and unilateral raceway wear caused by misalignment; seal deformation and grease leakage from axial tension leading to excessive clearance and belt deviation; fine coal and ore dust form abrasive slurry to accelerate bearing wear; outdoor humidity induces rust and fatigue spalling; impact load triggers crack propagation and outer ring rupture, resulting in conveyor shutdown. Roller replacement requires hoisting construction with long maintenance time and huge production loss.
2. Graded Core Advantages of NMT Spherical Roller Bearings for Conveyor Pulleys
NMT bearings are optimized in structure, material, sealing, rust prevention, lubrication and clearance, divided into standard industrial version, reinforced dust-proof version, outdoor waterproof anti-rust version, underground heavy-duty version and super-heavy customized version.
Self-Aligning Structure: Double-row thickened spherical rollers offer ±2.2° angular compensation to eliminate misalignment stress. Roller crowning withstands alternating axial force from belt deviation.
High-Strength Bearing Steel: ESR remelted bearing steel with double stress relief annealing balances surface wear resistance and core toughness, service life 4.5 times longer than ordinary bearings for non-stop 24h operation.
Graded Sealing Solution: Standard double-lip NBR seal for dry indoor working conditions; three-layer composite seal (steel dust cover + double lip oil seal + grease baffle) for high-dust underground mines; three-layer seal plus phosphating anti-rust treatment for port & open-air muddy sites.
Customized Internal Clearance: C0 for stable bend pulley operation, C3 for heat compensation of head drive pulley, C4 for heavy inclined conveyor impact buffering.
Pre-Filled Special Grease: Extreme pressure lithium grease for dust sites, water-resistant compound grease for outdoor sites, polyurea grease for high-temperature underground equipment to extend refueling cycle.
3. Conveyor Pulley Model Selection Guide
Head Drive Pulley (TD75, DTⅡ, DTL Coal Mine Conveyor): Reinforced C3 clearance bearing for high heat dissipation.
Tail Tension Pulley: Dust-proof reinforced bearing to block concentrated falling dust.
Bend & Pressure Pulley: Cost-effective C0 standard clearance bearing.
Underground Coal Mine Conveyor: Dust-proof & anti-rust integrated bearing for humid dusty roadways.
Open-Pit Mine & Port Conveyor: Waterproof anti-rust triple-seal bearing for rain and mud resistance.
Large Inclined Belt & Pipe Conveyor: C4 large clearance bearing to resist reverse impact of sliding materials.
Direct dimensional interchange for pulley overhaul without housing reboring.
4. Precision Machining & Factory Inspection
Super-finished spherical raceway reduces friction and temperature rise; stamped steel cage for regular use, solid brass cage for high-temperature heavy-duty drive pulleys. All finished products pass self-aligning test, impact fatigue test, high-temperature aging test, dust & water sealing test and clearance grading with complete inspection certificates. Pre-filled grease simplifies on-site assembly.
5. Assembly & Maintenance Cost Advantage
Fully interchangeable with original pulley bearings of DTⅡ, TD75, DTL series conveyors, compatible with cold press fitting and hot oil mounting. Factory preset assembly preload eliminates on-site shim adjustment, cutting pulley maintenance time by 60% and reducing conveyor shutdown loss.
6. Global Application Scenarios
Underground coal mine main conveyor, thermal power plant coal feeding conveyor, open-pit mine aggregate transportation belt, port bulk cargo handling conveyor, cement raw meal & clinker conveyor, construction waste recycling belt conveyor, grain depot bulk conveying equipment.
7. Spot Stock & Customized Service
Spot supply for mainstream models 22218, 22220, 22222, 22224, 22320, 22324, 22326 for immediate delivery. Custom non-standard bearings for super-long distance conveyor, heavy-duty pulley, anti-corrosion and low-temperature working conditions are available with short lead time. Professional engineers provide customized bearing selection plans to solve shaft seizure, belt deviation, dust-induced grease failure, outdoor rust damage and frequent bearing replacement problems, extend pulley service life and cut spare parts & downtime costs for industrial enterprises.