CAT 595-2938 Sleeve Bearing

CAT 595-2938 is a Caterpillar straight sleeve bearing (steel-backed bronze/sintered bronze composite), suitable for the boom/stick pin hinge points of Cat 320D/323D/324D/329D excavators. Its core function is to support the pin and reduce friction. The following is structured technical information.

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes Model 595-2938, straight-type flangeless sleeve bearing, suitable for pin diameter 85 mm (tolerance h7), single weight 1.86 kg, quantity per unit 2 pieces (1 on each side of the boom lower hinge point), used with pin 595-2937

Key Dimensions Inner diameter φ85 mm (tolerance H7: +0.03–0 mm), outer diameter φ95 mm (tolerance k6: +0.015–+0.002 mm), total length 70 mm (tolerance ±0.1 mm), chamfer at both ends 1×45°, inner hole surface roughness Ra≤0.8 μm, outer diameter surface roughness Ra≤1.6 μm

Material and Process Material is steel-backed bronze composite material (steel back Q235B, bronze layer CuSn8P, thickness 2.5 mm, containing solid lubricant), no surface coating, using powder metallurgy sintering + Rolling process, hardness HB 80–100, compressive strength ≥250 MPa

Performance parameters: Rated static load 180 kN, dynamic load 120 kN (linear velocity ≤0.8 m/s), operating temperature -30℃ to +120℃, coefficient of friction ≤0.15 (oil lubrication), compatible grease NLGI Grade 2 extreme pressure lithium-based grease

Compatible models: Excavators 320D/320D2/323D/324D/329D/330D, compatible with boom

Installation and maintenance points: Before installation, clean the bearing inner hole, outer diameter, and mounting hole. Check the bearing for cracks/chips/deformation. Cold shrink the bearing with liquid nitrogen (-196℃) (shrinkage approximately 0.12 mm) before pressing it into the mounting hole (interference 0.01–0.02 mm). Do not directly hammer the bearing end face.

Clearance Control: The radial clearance between the bearing and the pin should be 0.1–0.15 mm (ensuring this through matching the bearing’s inner diameter tolerance with the pin’s outer diameter tolerance). Check with a feeler gauge after installation. Excessive clearance can lead to impact wear, while insufficient clearance can cause overheating and seizure.

Lubrication Requirements: Before installation, apply grease (≥50 g) to the bearing’s inner bore. Replenish grease every 250 hours (inject through the grease fitting until new grease overflows) to prevent dry friction that could cause bearing burnout.

Troubleshooting: If abnormal noise, increased clearance, or oil leakage occurs, first check for bearing wear (inner diameter wear > 0.2 mm requires replacement), deformation of the mounting hole (roundness > 0.05 mm requires boring repair), or insufficient lubrication. If necessary, replace the bearing and correct the pin’s straightness to ≤ 0.03 mm/m.