Four Row Tapered Roller Bearings: Models, Structure, Features & Applications

Four row tapered roller bearings are professional heavy-duty rolling mill bearings, specially designed for ultra-heavy combined radial and axial loads in high-temperature metallurgical rolling environments. Featuring a standard O-type four-row tapered roller layout, separable structure and forced circulation lubrication design, these bearings deliver ultra-high rigidity, stable rolling accuracy and excellent impact resistance. With complete standard/large cone angle, straight/tapered bore and sealed/open configurations, they are the core supporting components for long-term continuous operation of hot rolling and cold rolling mill equipment.

1. Core Structure

Four row tapered roller bearings adopt industrial rolling mill heavy-duty optimized structure, adapting to high-load, high-temperature and polluted workshop working conditions:

•O-Type Four-Row Integrated Layout: Consists of two double-row inner cone assemblies, two independent outer cups and four sets of tapered rollers with reinforced cages. The standard O-type arrangement stably bears bidirectional axial force and ultra-large radial rolling pressure simultaneously.

•Dual Cone Angle & Bore Design: Available in standard cone angle and large cone angle versions for enhanced axial thrust capacity. Most models adopt straight cylindrical bores; 1:12 tapered bore (suffix K) customized models support quick installation with adapter sleeves for roll neck matching.

•Super-Finished Logarithmic Roller Profile: Rollers and raceways adopt logarithmic crowning super-finishing, effectively eliminating edge stress concentration caused by uneven heavy rolling pressure and reducing operating wear.

•W33 Circulating Lubrication Structure: Outer rings are equipped with standard W33 annular oil grooves and radial lubrication holes, supporting continuous forced oil circulation and rapid heat dissipation for high-temperature rolling mill working conditions.

•High-Strength Alloy Steel & Multi-Layer Sealing: Forged from high-alloy carburized steel with HRC 58–62 surface hardness and tough core to resist cyclic impact loads. Optional multi-layer labyrinth composite seals block iron oxide scale, cooling water and metal dust.

2. Key Product Features

•Ultra-High Heavy-Load Capacity: Four-row roller dispersed load structure withstands long-term ultra-large rolling pressure of hot and cold rolling mills, suitable for 24-hour continuous industrial production.

•Balanced Bidirectional Axial Resistance: Effectively offsets axial thrust generated by steel strip tension and rolling force deviation, ensuring stable rolling operation.

•Ultra-High Structural Rigidity: Minimal elastic deformation under peak loads, guaranteeing precise dimensional accuracy of steel plates, bars and strips after rolling.

•Easy Maintenance & Heat Dissipation: Fully separable components support independent disassembly and inspection. Matched with forced oil lubrication system to avoid bearing ablation from heat accumulation.

•Thermal Expansion Adaptation: C3/C4 enlarged internal clearance is standard configuration, compensating roll neck thermal expansion during high-temperature rolling.

3. Product Classification & Full-Series Models

3.1 Classification

•Cone angle: Standard cone angle, large cone angle (heavy axial thrust)

•Bore type: Straight cylindrical bore, 1:12 tapered bore (suffix K)

•Lubrication: W33 circulating oil groove type, open grease lubrication type

•Sealing: Open type, labyrinth anti-fouling sealed type

•Cage: Reinforced stamped steel cage, solid brass cage (ultra-heavy impact)

3.2 Mainstream Full-Series Models

Standard Universal Rolling Mill Models: 380632, 380636, 380640, 380644, 380648, 380652, 380656, 380660

W33 Lubrication Reinforced Models: 380632/W33, 380636/W33, 380640/W33, 380644/W33, 380648/W33

Tapered Bore K Series: 380632K, 380636K, 380640K/W33, 380644K/W33

Large Cone Angle High-Thrust Models: BT4-8078, BT4-8128, BT4-8182, BT4-8184, BT4-8092/W33

Clearance Custom Models: C3/C4 large clearance vibration-resistant series, P4/P5 high-precision rolling mill dedicated series

4. Application Scope

Four row tapered roller bearings are exclusively applied to metallurgical rolling mill equipment, including roughing mills, intermediate mills and finishing mills of hot strip mills, plate mills, bar mills and wire rod mills. They are also widely used in large section steel rolling lines, seamless steel pipe piercing mills and blooming mills, providing stable high-rigidity load support for heavy-load and high-temperature rolling production.

5. Product Advantages

Our four row tapered roller bearings adopt high-alloy carburized steel and super-finishing technology, featuring high hardness, strong impact resistance and stable high-temperature performance. O-type four-row structure realizes ultra-heavy radial and axial load capacity, while W33 lubrication and labyrinth sealing adapt to harsh rolling mill environments. Standard C3/C4 clearance solves thermal expansion problems, and separable structure reduces maintenance costs. All models comply with industrial rolling mill standards with high interchangeability, being reliable core components for metallurgical rolling equipment