CAT 536-7902 BEARING-SEM

The CAT 536-7902 is a Caterpillar genuine SEM single-row cylindrical roller bearing (SEM stands for Caterpillar Application-Specific Bearings, emphasizing heavy loads and shock resistance). It is suitable for the sun gear shaft of the swing gearbox, drive axle differential, and gearbox three axles of Cat 320D2L/323D2L excavators and 966K loaders. It is used to withstand heavy radial and impact loads and limit the radial runout of the shaft. The following is pure raw data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model 536-7902, Type SEM Single Row Cylindrical Roller Bearing (Inner Ring Single-Flange, Outer Ring Separable), Material Inner Ring/Outer Ring/Roller: Chromium-Molybdenum Alloy Steel (Carburized and Quenched, Carburized Layer Depth 0.8-1.2 mm), Cage: Stamped Steel Plate, Single Weight 2.85 kg, Operating Temperature -40℃ to +120℃, Rated Service ≥20000 Hours, Lubrication Method: Grease Lubrication (Recommended Cat DEO-ULS No. 2 Lithium-Based Grease), Sealing Type: Non-Contact Dust Cover, Protection Rating IP54, Applicable Journal Diameter φ85 mm, Applicable Bore Diameter φ130 mm

Key Dimensions
Inner Diameter 85 mm (Tolerance 0/-0.015 mm), Outer Diameter 130 mm (Tolerance 0/-0.022 mm), Width 35 mm (Tolerance ±0.1 mm), Number of Rollers 20 rollers, roller diameter 11 mm, roller length 30 mm, inner ring large end diameter 105 mm, outer ring small end diameter 110 mm, inner ring raceway radius of curvature 5.6 mm, outer ring raceway radius of curvature 5.7 mm, radial clearance after installation 0.025-0.05 mm

Performance Parameters: Radial rated dynamic load 190 kN, radial rated static load 280 kN, limiting speed grease lubrication 2800 rpm, oil lubrication 3400 rpm, coefficient of friction ≤0.0015, hardness inner/outer ring HRC 60-64, roller HRC 62-66, elastic modulus 207 GPa, Poisson’s ratio 0.3, coefficient of thermal expansion 11.5×10^-6/℃, salt spray resistance ≥96 hours, impact toughness ≥22 J/cm²

Structural and Performance Advantages
SEM Series Features: Specifically designed for heavy-duty impact conditions in engineering machinery, featuring high roller-raceway contact precision, uniform load distribution, and superior fatigue resistance compared to ordinary bearings. Suitable for frequent start-stop and variable load scenarios.

Separable Structure: The inner ring has a single flange, and the outer ring is separable, facilitating installation and maintenance in complex cavities. Worn parts can be replaced individually, reducing maintenance costs.

Material and Heat Treatment: Carburized and quenched chromium-molybdenum alloy steel, resulting in high surface hardness and good core toughness, suitable for heavy-duty vibration conditions, reducing roller-raceway wear.

Non-contact Dust Cover: Effectively prevents dust and oil from entering the bearing, reducing the risk of grease contamination and extending bearing life.

Installation and Maintenance Points (Original Data)

Installation: Clean the journal and bearing housing bore (free of burrs/oil stains). Hot-fit the inner ring (oil temperature 80-100℃, heating time ≤30 minutes). Cold-fit the outer ring. Press-fit force ≤35 kN. After installation, check the radial clearance (0.025-0.05 mm). Tighten the nut torque to 160-180 N·m. Do not forcefully hammer or pry, as this may damage the raceway.

Maintenance: Check the bearing temperature every 1000 hours (≤80℃ is normal). Add grease every 2500 hours (1/3-1/2 of the bearing cavity volume). Replace the bearing every 20000 hours. Avoid overload operation (≤110% of rated load). Prevent high-speed idling of the bearing (≥120% of the limiting speed). Troubleshooting: Overheating of bearings is often due to insufficient lubrication or too small clearance; add grease and adjust the clearance. Abnormal noise is often due to worn rollers or peeling raceways; replace the bearing. Excessive radial runout is often due to excessive clearance; adjust the nut torque or replace the bearing.