1. Main Bearing Failure Reasons for Fan Equipment

Boiler induced draft fans, centrifugal blowers and exhaust fans suffer shaft misalignment caused by frame settlement, shaft deflection, thermal deformation and assembly errors. Ordinary bearings bear eccentric load directly, resulting in unilateral raceway pitting, peeling and roller edge fracture.

High-speed rotation brings axial float and vibration, tearing standard seals to cause grease loss and dry friction overheating. High-temperature flue gas and dust invade bearing interior to form abrasive wear. Temperature alternation tightens bearing clearance and triggers thermal seizure. Sudden bearing failure leads to boiler interlock shutdown and complicated maintenance with high hoisting cost for impeller disassembly.

2. Core Advantages of NMT Fan Spherical Roller Bearings

Double-row spherical roller structure realizes angular deflection compensation to eliminate eccentric load from shaft bending, installation misalignment and foundation settlement, achieving uniform load distribution to avoid unilateral raceway damage.

C3/C4 enlarged radial clearance reserves expansion space for high-temperature shaft deformation to prevent heat seizure. Forged high-purity bearing steel with stress relief aging improves high-speed stability and vibration fatigue resistance.

Two cage options: one-piece solid brass cage for high-temperature heavy-duty fans with fast heat dissipation and deformation resistance; high-strength stamped steel cage for cost-effective conventional ventilation equipment.

Composite sealing solutions including double-lip skeleton rubber seal and graphite labyrinth seal lock grease and block dust & high-temperature flue gas intrusion. Two lubrication options of high-temperature synthetic grease and extreme-pressure grease adapt to normal ventilation and high-temperature exhaust fans.

Service life is over 4 times longer than ordinary cylindrical roller or deep groove ball bearings, reducing regular maintenance frequency and ensuring year-round stable operation of ventilation and exhaust systems.

3. Product Classification & Fan Condition Selection Guide

Boiler ID Fan High-Temp Main Shaft Bearing: C4 large clearance + brass cage + graphite labyrinth seal for flue gas below 300℃.

Centrifugal Blower Heavy-Duty Support Bearing: Standard spherical roller bearing to compensate shaft deflection eccentric load for high-pressure high-volume blowers.

Dust Removal Exhaust Fan Bearing: Double-lip dust-proof seal to block smoke and dust ingress.

Cooling Tower Outdoor Fan Bearing: Waterproof weather-resistant seal against moisture and rust corrosion.

Open Grease-Fitting Fan Bearing: External grease nipple for online greasing to flush internal dust for non-stop industrial fans.

Application Reference:

Boiler induced draft fan main shaft: C4 clearance brass cage high-temperature spherical roller bearing

High-pressure centrifugal blower both-end support: C3 clearance standard spherical roller bearing

Baghouse dust exhaust fan: Double-lip sealed dust-proof spherical roller bearing

Industrial cooling tower fan: Waterproof rust-proof spherical roller bearing

Old fan renovation: Direct dimensional replacement without bearing housing machining

4. Fan-Specific Material & Precision Machining Process

Inner/outer rings and rollers adopt carburized high-purity bearing steel. Forged blanks undergo high-temperature stress relief annealing. Mirror super-finishing for raceways and rollers reduces friction, lowers operating temperature and delays fatigue pitting.

Optimized raceway curvature achieves about 1° maximum misalignment compensation to match fan shaft deformation range. Integral turned brass cage has no welding seam for stable performance under high-speed vibration.

Flexible graphite end seal for high-temperature models resists hardening under high heat to block hot air conduction; aging-resistant NBR skeleton seal for normal-temperature models prevents grease corrosion and axial tear.

All finished bearings complete high-speed dynamic balance calibration to avoid amplified unit vibration caused by bearing imbalance and protect fan base, main shaft and coupling.

5. Assembly Compatibility & Factory Professional Testing

Standard ISO and national spherical roller bearing dimensions achieve full interchangeability with original fan bearings for plug-and-play replacement on old fans without housing or shaft modification. Supports adapter sleeve locking and interference hot mounting compatible with conventional fan assembly processes.

Finished products pass high-speed temperature rise endurance, angular self-aligning load, dust sealing protection, cold-heat cycle shock and axial float seal durability tests for graded selection by fan power, operating temperature and medium cleanliness.

Maintenance uses general bearing tools, shortens downtime with rapid maintenance after fan cooling.

6. Wide Application Scenarios

Thermal Power & Boiler: Induced draft fan, primary air fan, secondary air fan, boiler exhaust fan, hot air circulation fan main shaft bearings

Environmental Dust Removal: Baghouse dust fan, ESP induced draft fan, desulfurization & denitrification booster fan, waste gas exhaust fan

Industrial Ventilation: High-pressure centrifugal blower, factory air supply/exhaust fan, kiln combustion-supporting fan, material conveying fan

Refrigeration & Cooling: Large cooling tower fan, air cooler fan, water cooling unit circulation fan

Mining & Building Materials: Mine ventilation fan, cement kiln tail fan, aggregate drying induced draft fan, dust exhaust fan

7. Dimensional Interchangeability & Custom Fan Supporting Service

Standard fan spherical roller bearings are in stock for immediate delivery. Custom wide, thick, large-bore bearings for high-power fans and high-temperature anti-corrosion special bearings support urgent customized production.

Each batch is delivered with temperature rise test reports, metallographic inspection certificates and self-aligning performance test reports. Professional engineers configure clearance, cage and sealing structure based on fan power, medium temperature, flue dust concentration and shaft deflection to solve eccentric load peeling, high-temperature seizure, abrasive dust wear, seal grease leakage, vibration noise and frequent shutdown maintenance. Guarantee continuous operation of thermal power, environmental protection and ventilation systems and reduce overall fan operation and maintenance costs.