CAT 7S-4025 BEARING

CAT 7S-4025 is a Caterpillar genuine double-row self-aligning roller bearing with an inner diameter of 50 mm. It is suitable for the steering knuckle shaft, balance shaft, or gearbox intermediate shaft of Cat 824B/834 wheeled bulldozers and 825 series earthmoving compactors. It can simultaneously withstand radial loads and bidirectional axial loads under heavy-duty conditions, allowing for a small amount of misalignment (≤1.5°) between the shaft and bearing housing, ensuring the rotational accuracy and stability of the supported parts. The following is a professional technical and application guide:

Core Technical Parameters (Professional Version)

Item Details Basic Attributes Model 7S-4025, Type Double-row self-aligning roller bearing (including inner ring/outer ring/symmetrical spherical rollers/stamped steel cage, no seal), Suitable for Cat 824B/834 wheeled bulldozer steering knuckle shaft, 825B/C/G/H earthmoving compactor balance shaft, 980H loader gearbox intermediate shaft, D9R Track frame balance shaft bearing housing, material: inner/outer ring (SAE 52100 bearing steel, hardened to HRC 60-64), rollers (SAE 52100, HRC 62-66, symmetrical spherical profile), cage (SAE 1010 steel plate stamping, galvanized surface), inner diameter φ50 mm (tolerance JS6), outer diameter φ110 mm (tolerance P6), width 40 mm, single weight approximately 1.8 kg, rated radial load Cr≥110 kN, rated axial load Ca≥45 kN, rated static load Cor≥105 kN, operating temperature -40℃ to +120℃, lubrication method: forced oil lubrication (ISO VG 46 anti-wear hydraulic oil)/grease lubrication (NLGI 2 lithium-based grease), limiting speed (grease lubrication) ≤2800 rpm, (oil lubrication) ≤3600 rpm. Key dimensions. Inner ring large end face diameter φ70 mm (tolerance h7), outer ring small end face diameter φ90 mm (tolerance H7), number of rollers 28 (φ12 mm × 25 mm), cage window clearance 0.3-0.5 mm, inner ring raceway radius of curvature 25 mm (tolerance ±0.1 mm), outer ring raceway radius of curvature 25 mm (tolerance ±0.1 mm), radial clearance 0.08-0.12 mm (before installation), preload after installation 15-25 N・m
Material and Manufacturing Process: Bearing steel vacuum quenched + low-temperature tempered; rollers symmetrically spherically modified to reduce edge stress concentration; cage uses riveted structure; roller-raceway contact fatigue life ≥4000 hours (under rated load); surface roughness Ra≤0.4 μm (inner ring raceway) /≤0.6 μm (outer ring raceway); no surface defects (magnetic particle inspection qualified).
Compatible Models: Cat The 824B/834 wheeled bulldozer, 825B/825C/825G/825H earth compactor, 980H loader, and D9R tracked bulldozer are primarily used for heavy-duty support components such as steering knuckle shafts, balance shafts, and gearbox intermediate shafts. They are suitable for impact conditions with radial loads ≥80 kN and axial loads ≥35 kN, allowing for slight misalignment (≤1.5°) between the shaft and bearing housing to compensate for installation errors and deformation. Assembly fit: Interference fit with the shaft (interference 0.01-0.03 mm, hot fit temperature 80-100℃); clearance fit with the bearing housing (clearance 0.02-0.04 mm). After installation, pre-tighten with nuts to prevent loosening. After pre-tightening, axial runout ≤0.05 mm, radial runout ≤0.08 mm. Installation and Maintenance Points: Before installation, clean the inner and outer rings, journal, and bearing housing bore of the bearing. Check for cracks, missing rollers, and cage deformation. Measure the inner diameter/outer diameter/width and raceway runout to ensure they meet tolerances. Clean with solvent, dry, and apply a thin layer of oil for rust prevention.

During assembly, heat the inner ring to 80-100℃ (induction heating/oil bath, avoid localized overheating). Quickly install it onto the journal and position it. Press the outer ring into the bearing housing bore. Apply a preload of 15-25 N·m according to the model manual. Install and lock the lock nut.

Maintenance Recommendations: Check lubrication pressure and oil quality every 800 hours (oil lubrication) / replenish grease every 1000 hours (grease lubrication). Replace immediately if pitting occurs on the raceway, roller surface peeling, or radial clearance > 0.2 mm to prevent decreased transmission accuracy or bearing seizure.