CAT 518-8192 Self Aligning Bearing

CAT 518-8192 is a Caterpillar self-aligning roller bearing (double-row spherical roller structure), suitable for heavy-duty, shaft deflection, or misaligned installation conditions. It is commonly used in the slewing bearings, drive axles, and gearboxes of excavators and loaders. The following is structured technical and application information.

Core Technical Parameters

Item Details
Basic Attributes Model 518-8192, type is double row self-aligning roller bearing (symmetrical), material is high carbon chromium bearing steel (chromium content 1.4-1.65%), cage is stamped steel plate/brass, inner ring double raceway, outer ring spherical raceway, single weight approximately 7.2 kg, operating temperature -40℃ to +120℃, lubrication method is oil lubrication (ISO VG 68 anti-wear hydraulic oil) or grease lubrication (NLGI 2 lithium-based grease), fit tolerance: inner diameter H7, outer diameter r6, surface roughness Ra≤0.4 μm

Key Dimensions Inner diameter 100 mm (3.94 in), outer diameter 180 mm (7.09 in), total width 60 mm (2.36 in), chamfer 2×45°, radial clearance 0.12-0.18 mm, allowable self-aligning angle ≤1.5°, compatible shaft diameter 100 mm, rated load ≤280 kN
Compatible Models and Locations: Compatible with Cat 320GC/323GC excavators, 938M/950M loaders, 420F2/430F2 backhoe loaders. Mounted on the input shaft of the rotary gearbox, the main reducer shaft of the drive axle, the hydraulic pump drive shaft, etc., one unit per shaft. Used to bear radial heavy loads and compensate for installation errors.

Performance Parameters: Radial rated dynamic load ≥380 kN, radial rated static load ≥520 kN, maximum permissible linear speed ≤3 m/s, coefficient of friction ≤0.003 (oil film lubrication), fatigue life ≥12000 hours, limiting speed 2800 rpm (oil lubrication) / 1800 rpm (grease lubrication)

Structural and Performance Advantages: Self-aligning capability: The outer ring spherical raceway can compensate for misalignment errors between the shaft and the bearing housing (≤1.5°), adapting to shaft deflection or installation deviation conditions, reducing edge stress and wear risk.

Double-row roller design: Two rows of symmetrical spherical rollers ensure uniform load distribution and strong radial load capacity, capable of withstanding bidirectional axial loads (≤30% of radial load), with excellent impact and vibration resistance.

Strong material and cage: High-carbon chromium bearing steel, quenched (hardness 60-64 HRC), provides excellent wear resistance and fatigue resistance; stamped steel cage is suitable for medium and high speeds, while brass cage is suitable for heavy-load/impact conditions, preventing roller tilting and jamming.

Suitable for harsh working conditions: Can operate stably for extended periods in dusty, impact, and variable load environments, making it more suitable for the complex working conditions of engineering machinery compared to deep groove ball bearings.

Installation and maintenance points:
Installation process: Clean the journal and bearing housing bore, ensuring no burrs or rust; cold fit (interference 0.02-0.04 mm), press in with a special clamping block, do not strike; after installation, check radial clearance and end face runout (≤0.02 mm); install the grease fitting and fill with oil until overflowing.

Maintenance Cycle: Check lubrication status and replenish oil/grease every 1000 hours; check bearing temperature (≤80℃) and vibration every 2500 hours; disassemble and inspect every 4000 hours, replacing the bearing when the inner diameter wear exceeds 0.2 mm; shorten to 500-800 hours under severe operating conditions.

Common Faults and Solutions: Excessive temperature rise is often due to insufficient lubrication, requiring increased oil supply or replacement with higher viscosity oil; abnormal noise is often due to excessive clearance, requiring adjustment or replacement of the bearing; roller damage is often due to foreign object intrusion, requiring improved sealing and cleaning.