CAT 8F-3225 Spherical Roller Bearing

The CAT 8F-3225 is a genuine Caterpillar double-row self-aligning roller bearing, suitable for Cat mini loaders (such as 906H/907H) wheel hubs and topsoil loosener rotating shaft ends. It is used to bear heavy radial loads and certain bidirectional axial loads, compensating for shaft misalignment and skew. The following is pure raw data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes Model 8F-3225, Type Double Row Self-Aligning Roller Bearing (Symmetrical Spherical Rollers, Separable Inner Ring), Material Inner Ring/Outer Ring/Rollers: Chromium-Molybdenum Alloy Steel (Carburized and Quenched, Carburized Layer Depth 0.8-1.2 mm), Cage: Stamped Steel Plate, Single Weight 1.85 kg, Operating Temperature -40℃ to +120℃, Rated Service Life ≥18000 Hours, Lubrication Method: Grease Lubrication (Recommended Cat DEO-ULS No. 2 Lithium-Based Grease), Sealing Type: Non-Contact Stamped Steel Plate Dust Cover, Protection Rating IP54, Applicable Journal Diameter φ50 mm, Applicable Bore Diameter φ100 mm

Key Dimensions Inner Diameter 50 mm (Tolerance 0/-0.015 mm), Outer Diameter 100 mm (Tolerance 0/-0.020 mm), Width 30 mm (Tolerance ±0.12 mm) Roller configuration: 28 rollers (14 in each double row), roller diameter 10 mm, roller length 22 mm, spherical curvature radius R50 mm, inner ring flange height 5 mm, outer ring raceway curvature radius R52 mm, clearance range C3 (0.025-0.045 mm).

Performance parameters: Radial rated dynamic load 85 kN, axial rated dynamic load 25 kN, radial rated static load 72 kN, axial rated static load 20 kN, limiting speed grease lubrication 3600 rpm, oil lubrication 4500 rpm, coefficient of friction ≤0.003, hardness inner/outer ring HRC 60-64, roller HRC 62-66, elastic modulus 208 GPa, Poisson’s ratio 0.3, coefficient of thermal expansion 11.6×10^-6/℃, salt spray resistance ≥72 hours, impact toughness ≥20. J/cm² Structural and Performance Advantages

Double-row self-aligning structure: The spherical rollers and raceway design compensate for ≤2° shaft misalignment, suitable for hub shafts and other areas prone to misalignment, reducing edge stress.

Material and Heat Treatment: Carburized and quenched chromium-molybdenum alloy steel, with a wear-resistant surface and a strong core, capable of withstanding frequent start-stop cycles and impact loads, reducing early fatigue spalling.

Stamped cage: Lightweight design guides the rollers to run smoothly, reducing frictional heat generation and improving high-speed stability.

Non-contact dust cover: Prevents dust intrusion, reduces grease contamination, suitable for dusty working environments, and extends maintenance intervals.

Installation and Maintenance Points (Original Data)

Installation: Clean the journal and bearing housing bore (free of burrs/oil stains). Ensure an interference fit for the inner ring (hot fitting recommended, oil temperature 80-90℃, heating time ≤20 minutes). Ensure a clearance fit for the outer ring. Press-fit force ≤25 kN. After installation, check the radial clearance with a dial indicator (0.025-0.045 mm). Tighten the nut to a torque of 120-140 N·m. Do not strike the raceway or rollers.

Maintenance: Check the bearing temperature every 600 hours (≤80℃ is normal). Add grease every 1500 hours (1/3 of the bearing cavity volume). Replace the bearing every 18000 hours. Avoid overload operation (≤110% of rated load) and prevent high-speed idling (≥120% of the limiting speed). Troubleshooting: Overheating is often caused by insufficient lubrication or improper clearance; add grease and adjust the clearance. Abnormal noise is often caused by worn rollers or foreign objects entering the bearing; replace the bearing. Excessive vibration is often caused by excessive clearance or shaft misalignment; adjust the clearance or correct the shaft system.