CAT 177-4144 Bearing – Cup(Debris Resistant)

CAT 177-4144 is a Caterpillar single-row tapered roller bearing outer ring (cup-shaped outer ring), suitable for the travel motor and final drive of excavators such as the 320D/323D. It is used in conjunction with the inner ring and roller assembly to form a complete bearing pair, bearing large radial and bidirectional axial loads. The following is structured technical information.

Core Parameters (Professional Version)

Project Details
Basic Attributes Model 177-4144, single-row tapered roller bearing outer ring (cup), 1 piece per unit, compatible with tapered roller bearing assemblies, used with inner rings (e.g., 177-4145) and roller sets, for use in travel motors/final drive shaft systems, suitable for medium-high speed and heavy-duty applications.

Key Dimensions Inner diameter (compatible roller set outer diameter) 100 mm, outer diameter 140 mm, width 35 mm, cone angle 12°30′, outer ring raceway curvature radius R5.2 mm, interference fit 0.015–0.025 mm, end face runout ≤0.01 mm

Material and Process Material is chromium-molybdenum bearing steel (AISI 52100/SUJ2), surface carburized and quenched HRC60–64, raceway precision IT5, surface roughness Ra≤0.4 μm, chamfered. C2×45°
Performance Parameters: Suitable bearing assembly: Radial rated dynamic load ≈ 85 kN, radial rated static load ≈ 120 kN, limiting speed ≤ 3500 rpm, operating temperature -40℃ to +120℃, axial load capacity ≈ 30%–50% of radial load.
Compatible Machines: Cat 320D/320D2/323D/323D2/324D/326D excavators, suitable for travel motor and final drive tapered roller bearing assemblies, matching inner ring model 177-4145.
Installation and Maintenance Points: Before installation, clean the outer ring raceway and housing bore. The housing bore surface hardness ≥ HRC30, roughness Ra ≤ 1.6 μm, roundness ≤ 0.01 mm, free of burrs and rust.

Use hot fitting (heated to 80–100℃) or cold pressing assembly, pressing evenly with specialized tooling to avoid outer ring deformation or raceway damage, ensuring uniform contact with the inner ring and roller assembly.

After assembly, check radial clearance to be 0.03–0.05 mm and end face runout to ≤0.02 mm. Fill with Cat 106-9900 grease (1/3–1/2 of the bearing cavity volume).

Every 1500 hours, check the outer ring raceway for wear and cracks. Replace immediately if pitting, peeling, or other abnormalities are found to prevent bearing assembly failure.