CAT 549-3113 Self Aligning Spherical Plain Bearing

CAT 549-3113 is a Caterpillar double-row self-aligning roller bearing (with oil hole/groove and chip-proof seal), suitable for heavy-duty eccentric applications such as the Cat 336D2/349D excavator slewing bearing and the 980M loader drive axle main reducer. It is used for radial heavy-duty applications with bidirectional axial positioning and can compensate for ≤2° shaft misalignment. The following is professional structured information.

Core Parameters (Professional Version)

Project Details
Basic Attributes Model 549-3113, Double Row Self-Aligning Roller Bearing (Cylindrical Bore, with W33 Oil Hole and Groove), Inner Diameter φ120 mm (Tolerance H7: 0–+0.035 mm), Single Weight 6.8 kg, Radial Clearance CN Grade (0.12–0.18 mm), Quantity 1 per Unit, Used in Heavy-Duty Eccentric Shaft Systems (e.g., Input Shaft of Rotary Gearbox / Differential Shaft of Drive Axle)

Key Dimensions Inner Diameter φ120 mm (Tolerance JS6: ±0.01 mm), Outer Diameter φ215 mm (Tolerance 0–-0.04 mm), Width 58 mm (Tolerance ±0.2 mm), Roller Diameter φ15 mm, Number of Rollers 28, Inner Ring Flange Thickness 8 mm, Outer Ring Oil Hole φ5 mm, Chamfer at Both Ends 1.5 mm

Material and Manufacturing Process Inner/Outer Ring is GCr15SiMn bearing steel (quenched + tempered, hardness 60–64 HRC, carburized layer depth 1.2–1.5 mm); rollers are GCr15 bearing steel (integral quenching, hardness 61–65 HRC, roundness ≤0.002 mm); cage is integral stamped steel plate (SPCC + quenched, tensile strength ≥450 MPa); seals are nitrile rubber (NBR) + metal skeleton, chip protection rating IP54.

Performance parameters: Rated radial load 520 kN, rated axial load 180 kN, rated static load 780 kN, permissible linear velocity ≤6 m/s, operating temperature -40℃ to +120℃, coefficient of friction ≤0.003 (oil lubrication), compatible with ISO VG 100–150 gear oil, with W33 oil hole and groove (forced lubrication, pressure ≥50 kPa).

Compatible models: Cat 336D2/349D/352F Excavators (slewing gearbox input shaft), 980M/982M Loaders (drive axle main reducer shaft), D8T/D9T Bulldozers (final drive output shaft), compatible bearing housing bore φ215 J7 (+0.01–-0.01 mm)

Installation and Maintenance Points: Before installation, clean the journal (surface roughness Ra≤0.8 μm, no scratches/burrs) and housing bore. Use the hot fitting method (oil temperature 80–90℃, heating time ≥30 min) or a special press to evenly press in (press the inner ring end face, pressing force ≤80 kN). Do not strike the outer ring. The journal needs to be tempered to HB 240–280 and surface hardened to HRC 45–50 (hardened layer ≥2 mm). Clearance Control: After installation, measure the radial clearance with a plug gauge to ensure it is 0.12–0.18 mm. If the clearance exceeds the tolerance, adjust by grinding through the bearing housing bore or by replacing the bearing. For eccentric operation, C3 clearance (0.18–0.25 mm) is recommended.

Lubrication Requirements: Apply extreme pressure lithium-based grease (NLGI 2 grade) before installation. During operation, force lubrication through the W33 oil hole (flow rate ≥1.5 L/min). Check the oil quality/quantity every 1500 hours to prevent roller end face wear.

Troubleshooting: If abnormal noise/temperature rise occurs, first check for roller spalling (>0.05 mm requires replacement), cage deformation, or insufficient lubrication. If necessary, replace the bearing and clean the cavity of wear debris. For eccentric operation, the shaft coaxiality must be corrected simultaneously.