CAT 9T-3873 BEARING AS

CAT 9T-3873 is a Caterpillar genuine single-row tapered roller bearing assembly (including inner ring/outer ring/rollers/cage), suitable for radial and bidirectional axial composite load support in transmission components such as hydraulic pumps and gearboxes. The following is pure original data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes Model 9T-3873, Type Single-row tapered roller bearing assembly, Material GCr15SiMn bearing steel (carburized and quenched), Single weight 0.86 kg, Operating temperature -40℃ to +120℃, Rated radial dynamic load 132 kN, Rated radial static load 185 kN, Rated axial dynamic load 65 kN, Rated axial static load 120 kN, Lubrication method grease lubrication / oil lubrication, Fit tolerance P6, Corrosion resistance ≥96 hours salt spray, Suitable shaft diameter 55 mm, with stamped steel cage, Surface treatment blackened oxide + anti-rust oil coating

Key Dimensions (Metric / Imperial) Inner diameter 55 mm (2.165 in), Outer diameter 90 mm (3.543 in), Total width 23 mm (0.906 in), Roller diameter 7.5 mm, Number of rollers 18 Features: 15° contact angle, R1.5 mm chamfer, ≤0.02 mm flatness, Ra≤0.8 μm surface roughness, +0.015/-0.00 mm hole diameter tolerance, +0.020/-0.01 mm outer diameter tolerance, +0.08/-0.04 mm width tolerance. Performance parameters: Surface hardness HRC 61-65, core hardness HB 200-220, limiting speed 3200 rpm (grease lubrication)/4000 rpm (oil lubrication), coefficient of friction ≤0.0025 (lubricated state), coefficient of thermal expansion 11.8×10^-6/℃, radial clearance 0.012-0.022 mm, suitable tightening torque 110-130 Nm. N·m, no sealed structure, requires a separate sealing ring.

Structure and Adaptability Characteristics

Combined Load Bearing: Tapered roller design, simultaneously bearing radial and bidirectional axial loads, suitable for hydraulic pump spindles, gearbox input shafts, and other components requiring positioning and load bearing, dispersing composite stress in the shaft system and improving component operational stability.

Cage Stability Design: Stamped steel plate cage with separated rollers, suitable for medium- and high-speed rotation conditions, ensuring uniform roller distribution, reducing friction and wear, lowering vibration and noise, and extending bearing life.

Precise Positioning Adaptation: Strict dimensional and tolerance control ensures a tight fit with the shaft and bearing housing after installation, adapting to the high-precision positioning requirements of transmission systems, reducing impact loads caused by clearances, and ensuring power transmission efficiency.

Compatible Models and Application Scenarios

Hydraulic System: Adapted to the main pump and pilot pump spindle supports of 320D and 323D excavators, bearing radial and axial combined loads under high-pressure conditions, ensuring stable pump operation.

Transmission: Supports the first and second axle shafts of the 966H and 972H loader transmissions, transmitting power and bearing the radial and axial loads generated by gear meshing, reducing component wear.

Other: Supports transmission components of some Caterpillar bulldozers and road rollers, suitable for medium-to-high speed and heavy-load conditions, ensuring the reliability of the transmission system connection.

Installation and Maintenance Points (Original Data)

Installation: Clean the shaft, bearing housing, and bearing assembly, ensuring they are free of oil stains and metal shavings. Inspect the bearings for cracks, deformation, or roller damage; ensure they rotate freely without jamming.

Hot installation (heating temperature 80-100℃) or cold pressing installation (pressing force ≤75 kN). Do not hammer or strike. The bearing and shaft should have an interference fit (interference 0.015-0.022 mm). Ensure proper installation without misalignment.

After installation, check that the radial clearance meets requirements. When installing the sealing ring, ensure the sealing surface fits snugly. Run for 30 minutes, monitoring the temperature to ≤80℃.

Maintenance: Check lubrication and bearing clearance every 1000 hours. For grease lubrication, add NLGI 2 lithium-based grease. For oil lubrication, change the lubricating oil regularly (every 2000 hours).

Replace immediately if roller wear, cage damage, or clearance exceeds 0.04 mm to prevent shaft vibration or seizure.