CAT 129-7286 BEARING

CAT 129-7286 is a Caterpillar genuine single-row tapered roller bearing (including inner ring/outer ring/rollers/cage assembly), suitable for heavy-duty rotating parts such as gearboxes and drivetrains. It can simultaneously withstand radial and unidirectional axial loads, suitable for medium-to-low speed, high-load conditions, ensuring stable operation of the transmission system. Cat®… The following are key information.

Core Technical Parameters

Item Details
Part Model: CAT 129-7286 (Single Row Tapered Roller Bearing, Complete Assembly)

Material: Bearing steel (chromium-molybdenum alloy), inner and outer rings and rollers are quenched and tempered, hardness HRC 60-64; cage is made of stamped steel plate with anti-rust coating.

Key Dimensions: Inner diameter 50.8mm (2.000in), outer diameter 100mm (3.937in), width 25.4mm (1.000in), taper angle 12°30′, suitable for φ50.8mm shaft diameter.

Single Weight: Approx. 0.92kg (2.03 lbs)

Compatible Models: CAT 950H/966H loaders, 320D/323D excavators, D6N bulldozers, etc., for gearbox output shaft, drive shaft support, and rotating ends of some hydraulic pumps/motors.

Performance Characteristics Rated radial load ≥110kN, rated axial load ≥55kN, limiting speed 2800 RPM (grease lubrication) / 3600 RPM (oil lubrication), operating temperature -40℃ to +120℃, resistant to impact and alternating loads.

Structure and Core Functions

Composite Load Bearing: Tapered rollers make line contact with the raceway, allowing simultaneous radial and unidirectional axial loads. Radial load capacity is increased by approximately 40% compared to deep groove ball bearings of the same size, making it suitable for complex stress conditions in transmission systems.

Precise Positioning: Inner and outer rings are separable, and clearance can be adjusted during installation (0.02-0.05mm), ensuring radial and axial positioning accuracy of the shaft system and reducing runout and abnormal noise during operation.

High-Efficiency Transmission: Rollers are ultra-precision ground (roughness Ra≤0.1μm), and guided by a cage, reducing friction loss, improving transmission efficiency, and reducing energy consumption and heat generation.

Durable and Reliable: Made of bearing steel with overall quenching treatment, its fatigue life is 2-3 times longer than that of ordinary carbon steel bearings. Suitable for harsh working conditions such as dust and vibration, reducing maintenance frequency.

Suitable Scenarios and Installation/Maintenance Points

Suitable Scenarios: Used in rotating parts of engineering machinery such as gearboxes, drive shafts, and hydraulic pumps/motors that need to withstand both radial and axial loads simultaneously. Suitable for low to medium speed (≤2000 RPM), high load, and frequent start-stop conditions.

Installation Specifications: Clean the shaft diameter and bearing housing bore, ensuring no burrs, oil stains, or rust. Use heat mounting (heat the bearing to 80-100℃) or cold pressing for installation. Do not force it, as this may damage the raceways/rollers.

After installation, adjust the axial clearance according to the equipment manual. For grease lubrication, add lithium-based extreme pressure grease (filling 1/3-1/2 of the bearing’s internal space). For oil lubrication, ensure the oil level covers the center of the lowest roller.

Tighten the bearing end cap bolts to the specified torque (typically 100-150 N·m) to ensure reliable bearing positioning.

Maintenance Recommendations: Check the bearing condition every 1000 operating hours. If abnormal temperature (>80℃), unusual noise, or clearance exceeding 0.15mm is observed, replace the bearing immediately.

Regularly change the lubricating oil (every 2000 operating hours for gearbox bearings) or replenish the grease (every 500 operating hours) to avoid premature wear caused by dry friction.

For long-term storage, apply anti-rust grease and wrap the bearing for protection to prevent corrosion.