1. Typical Bearing Failure Problems in High-Temperature Working Conditions

Furnaces, heat treatment trolleys, metallurgical hot rollers and drying tunnels operate under high temperatures. Ordinary grease carbonizes rapidly to form hard carbon slag, blocking bearing rotation and causing shaft seizure. Conventional bearing steel undergoes temper softening at high temperature, resulting in raceway out-of-roundness and thermal expansion jamming.

Frequent start-stop of furnaces creates drastic temperature alternation, triggering thermal fatigue cracks and bearing fragmentation. High-temperature dust and oxide scale sinter on bearing surfaces to form abrasive particles, accelerating raceway wear. High-temperature equipment requires long cooling time for disassembly and replacement, leading to massive production loss and high spare parts cost.

2. Core Advantages of NMT High-Temperature Bearings

NMT high-temperature bearings adopt heat-resistant alloy steel to avoid high-temperature temper softening and maintain surface hardness. Two lubrication solutions are available: synthetic fluorine high-temperature grease for medium continuous heat conditions, and graphite solid self-lubricating structure for oil-free ultra-high-temperature closed furnaces. Pre-set enlarged internal clearance offsets thermal expansion to eliminate expansion seizure.

Multi-layer heat insulation dust seals block hot air and sintered oxide slag to protect internal moving parts. Secondary high-temperature aging treatment releases internal stress completely to prevent thermal cycle cracks. High-temperature anti-oxidation passivation reduces oxide peeling and abrasive wear, extending service life by over 4 times compared with ordinary bearings, eliminating regular high-temperature greasing maintenance.

3. Product Classification & Condition Selection Guide

Medium-Temp Grease-Lubricated Bearing: Drying line rollers, boiler fans, heat conveyor rollers for 150℃–300℃ continuous operation with periodic greasing.

Graphite Self-Lubricating Ultra-High-Temp Bearing: Quenching furnaces, annealing furnaces, tunnel kiln rollers for 300℃–650℃ oil-free sealed high-temperature chambers.

Large Clearance Heavy-Duty High-Temp Bearing: Metallurgical hot rolling rollers, hot material support shafts for high temperature and heavy impact load.

Integrated Heat Insulation Bearing Unit: Furnace end transmission, hot air circulation fans with built-in heat insulation to reduce operating temperature.

Open High-Temperature Bearing: Custom high-temperature gearbox assembly for external oil mist or solid lubrication systems.

Application Suggestion:

Tunnel kiln trolley support & furnace conveyor roller: Graphite self-lubricating ultra-high-temperature bearings

Boiler induced draft fan & hot air fan: Medium-temperature grease lubricated high-temperature bearings

Metallurgical hot rolling conveyor roller: Large clearance heavy-duty high-temperature bearings

Drying curing line shaft: Standard sealed high-temperature bearings

Old high-temperature equipment renovation: Direct dimensional replacement without shaft base modification

4. Heat-Resistant Material & High-Temperature Stabilization Process

Cr-Mo heat-resistant alloy steel is adopted for rings and rolling elements. Forged blanks undergo high-temperature stress relief annealing before precision raceway super-finishing to reduce high-temperature impurity adhesion. Two-stage quenching plus high-temperature aging stabilizes metallographic structure to keep hardness and dimensional stability under persistent high heat.

High-strength graphite composite or solid brass cages realize fast heat dissipation and long-term solid lubrication. Two sealing options: FKM fluoro rubber for medium-temperature dust sealing, flexible graphite packing for ultra-high-temperature end sealing, resisting high-temperature melting and cracking. No low-melting components for harsh furnace peripheral environments.

5. Assembly Adaptability & Factory High-Temperature Testing

Standard overall dimensions match national and ISO bearing standards. Internal clearance is graded by operating temperature for plug-and-play replacement without machining on shafts or housings. Supports press fitting, set screw locking and flange mounting for rollers, main shafts and eccentric supports.

Finished products pass high-temperature endurance aging, cold-heat cycle shock, thermal expansion measurement, dust sintering simulation and rotational torque inspection with clear temperature rating labeling for accurate selection. Regular bearing tools support assembly and maintenance, shortening overhaul downtime for high-temperature equipment.

6. Wide Application Scenarios

Heat Treatment Industry: Quenching furnace, annealing furnace, sintering kiln, heat treatment trolley roller support bearings

Metallurgical Hot Rolling: Hot rolling conveyor roller, hot billet carrier, continuous casting machine high-temperature support bearings

Drying & Curing: Building material drying kiln, coating curing tunnel, grain dryer, chemical raw material drying drum bearings

Thermal Power Equipment: Boiler induced draft fan, hot air blower, incinerator exhaust fan high-temperature bearings

Asphalt & Building Materials: Asphalt mixing drum, aggregate heating drum, high-temperature material conveyor bearings

Ceramic & Refractory: Ceramic tunnel kiln, refractory brick firing kiln car, internal furnace drive roller bearings

7. Dimensional Interchangeability & Custom High-Temperature Technical Service

NMT high-temperature bearings comply with international dimensional standards for full interchangeability with conventional bearings, retaining original bearing housings and drive shafts without overhauling spare parts management. Standard sealed models are in stock; ultra-high-temperature oversized kiln rollers and customized solid lubrication bearings support fast lead-time delivery.

Each batch is delivered with high-temperature aging test reports and metallographic inspection certificates. Professional engineers configure clearance, lubrication and sealing schemes based on peak temperature, running hours, load and thermal cycling to solve grease coking seizure, thermal expansion jamming, thermal cracking, sintering wear and frequent shutdown maintenance, ensuring long-term continuous operation of kiln equipment and cutting comprehensive high-temperature operation costs.