CAT 6V-8500 55mm Inner Diameter Caged Roller Bearing

The CAT 6V-8500 is a Caterpillar single-row cylindrical roller bearing (with cage), with an inner diameter of 55mm. It is suitable for medium- and high-speed, medium-load transmission components such as the hydraulic pump of Cat 312D/320D excavators, the input shaft of the gearbox of 938K loaders, and the drive shaft of 120M graders. It is primarily used to withstand pure radial loads, ensuring smooth high-speed operation and positioning of the shaft system, and limiting the radial runout of the shaft. The following is structured technical and application information:

Core Technical Parameters
Item Details
Basic Attributes
Model 6V-8500, Single-row cylindrical roller bearing (with stamped steel cage, non-separable type), suitable for 312D/320D excavator hydraulic pumps, 938K loader gearboxes, 120M grader drive shafts, material is chromium bearing steel (GCr15, quenched HRC 60-64), operating temperature -40℃ to +120℃, single weight approximately 0.92 kg, suitable for oil lubrication, rated radial dynamic load ≥88 kN, rated radial static load ≥75 kN, operating speed ≤4500 rpm, wear life ≥7000 hours, used for pure radial load bearing in transmission parts to ensure smooth shaft operation and reduce radial runout

Key Dimensions
Inner diameter 55.00 mm (2.165 in, tolerance P6, +0.008/-0.012 mm), outer diameter 90.00 mm (3.543 in, tolerance P6, +0.012/-0.020 mm), total width 20.00 mm (0.787 in, tolerance ±0.10 mm), rolling element diameter 8.0 mm, cage made of stamped low carbon steel plate (SPCC), number of rollers 12, inner ring chamfered at both ends C1.5 mm, outer ring chamfered at both ends C1.0 mm, inner hole roughness Ra≤0.8 μm, no oil groove or oil hole, suitable for standard journals and bearing housings.

Material and Process: GCr15 chromium bearing steel → forging → spheroidizing annealing → rough turning → finish turning → quenching (840℃ oil quenching) → low temperature tempering (180℃ holding for 2h) → fine grinding → ultra-precision grinding → assembly (rollers + cage + inner and outer rings) → rust prevention treatment. It possesses high hardness, high wear resistance, and good dimensional stability, suitable for medium and high speed, pure radial load conditions.

Compatible Models: Cat This shaft is suitable for the hydraulic pump input shaft of 312D/320D excavators, the gearbox input shaft of 938K/950GC loaders, the drive shaft of 120M/140M graders, and the hydraulic motor output shaft of 420D skid steer loaders. It is designed to withstand pure radial loads and is suitable for high-speed, medium-load transmission components, extending shaft life. Assembly fit: Compatible with 55.00 mm diameter journals (tolerance k5, +0.010/+0.001 mm), and 90.00 mm diameter bearing housing bores (tolerance H7, +0.030/0 mm). Interference fit: 0.001-0.010 mm (journal to inner ring); clearance fit: 0.012-0.030 mm (outer ring to bearing housing). Hot fitting (oil temperature 80-90℃) or cold fitting is acceptable. Do not hammer during installation. Radial runout after installation should be ≤0.015 mm. mm Installation and Maintenance Points: Before installation, clean the journal, bearing housing bore, and bearing. Inspect the surfaces for scratches, rust, and dents. Measure the inner diameter of the journal and inner ring, and the outer diameter of the bearing housing bore and outer ring to ensure the interference fit and clearance meet requirements. The surface roughness of the bearing housing bore should be Ra ≤ 1.6 μm.

Use the hot fitting method (immerse the bearing in clean machine oil at 80-90℃ for 15-20 minutes). Use a special sleeve to vertically press the bearing into the journal, ensuring the bearing end face fits snugly against the shaft shoulder. For the cold fitting method, use a hydraulic nut to evenly press the bearing in. Do not directly strike the bearing outer ring or cage with a hammer to prevent deformation and damage to the rollers.

Maintenance recommendations: Check bearing clearance every 1500 hours. Replace immediately if radial clearance > 0.12 mm or if abnormal noise or temperature rise occurs. Use ISO VG 32 hydraulic oil for daily lubrication. Keep the oil level at the center of the lowest rolling element of the bearing. Check the oil quality every 400 hours and replace the filter element regularly to prevent impurities from entering the bearing.