CAT 490-8307 BEARING-CUP

CAT 490-8307 is the outer ring (bearing housing ring) of Caterpillar mast pulley bearings, which is compatible with mast pulley bearing assemblies of Cat MD6250 rotary drilling rigs and other models. It is used to provide stable installation and low-friction rotational support for pulley bearings, withstand radial impact loads, and ensure the smooth operation of the wire rope in the hoisting system. It is a key load-bearing component of the hoisting mechanism, Cat® Parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 490-8307, Type: Single-row deep groove ball bearing outer ring (bearing housing ring), Material: Chromium-molybdenum alloy steel (quenched and tempered HRC32-38), Surface: Carbonitriding (hardened layer 0.3-0.5 mm, surface hardness HRC58-62), Single weight: Approximately 0.85 kg, Applicable temperature: -30℃ to +120℃, Suitable media: Mineral oil, grease, Corrosion resistance: ≥72 hours salt spray

Key Dimensions
Inner diameter: 107.95 mm (tolerance 0/-0.03 mm), Outer diameter: 140.00 mm (tolerance 0/-0.05 mm), Width: 28.00 mm (tolerance ±0.10 mm), Groove curvature radius: 12.50 mm, Groove surface roughness: Ra≤0.4 μm, Chamfered ends C2×45°, radial runout ≤0.02 mm, end face perpendicularity ≤0.03 mm
Compatible Models and Applications: Compatible with Cat MD6250 rotary drilling rig mast pulley bearing assembly, one piece per pulley, installed between the mast pulley housing and the bearing rolling elements, supporting pulley rotation and positioning the bearing, bearing the radial load and impact of the hoisting wire rope.

Performance Parameters: Rated radial load ≥180 kN, fatigue life ≥1000 hours (under rated load), impact load ≥250 kN (instantaneous), coefficient of friction μ≤0.002 (grease lubrication), suitable speed ≤150 r/min

Structural and Performance Advantages: High strength load-bearing capacity: Chromium-molybdenum alloy steel matrix combined with carbonitriding surface treatment, possessing both high hardness and toughness, capable of withstanding heavy loads and frequent impacts, suitable for the alternating loads of drilling rig hoisting operations.

High-precision positioning: Strict dimensional and geometric tolerance control ensures bearing coaxiality during installation, preventing pulley runout that could cause wire rope wear or slippage, thus improving operational stability.

Corrosion and wear resistance: Surface hardening treatment enhances wear resistance, and a carbonitriding layer improves corrosion resistance, making it suitable for outdoor, humid, and dusty environments and extending component lifespan.

Stable installation and compatibility: Standard chamfered design facilitates cold-press installation, precisely matching the original mast pulley housing without additional processing, resulting in high installation efficiency.

Installation and maintenance points: Before installation, clean the outer ring and mast pulley mounting holes, checking for cracks on the outer ring and scratches on the grooves. Use cold-press installation (pressure ≤80 kN), and strictly avoid striking or damaging the grooves. After installation, check the outer ring end face to ensure proper fit with the housing (gap ≤0.1 mm), ensuring the bearing assembly rotates freely without jamming.

Every 500 hours of maintenance: Replenish with lithium-based grease (NLGI 2), check for loose outer rings and worn raceways (replace if wear ≥ 0.1 mm), and inspect pulley seals to prevent dust and moisture from entering and damaging the bearing.

Prioritize genuine parts. Aftermarket parts may have insufficient material strength or low raceway precision, easily leading to premature bearing failure, pulley seizure, and compromised lifting safety.