CAT 515-7756 2.155\ Inner Diameter Straight Sleeve Bearing

CAT 515-7756 is a Caterpillar single-row deep groove ball bearing, commonly used in low-to-medium speed, medium radial load applications such as hydraulic pumps, gearbox input shafts, and fan hubs in excavators and loaders. It is compatible with Cat 320D/336D excavators, 950M/966M loaders, and other models. It can withstand radial loads and is suitable for slight bidirectional axial loads, making it a fundamental component for ensuring the smooth operation of rotating parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 515-7756, Type: Single-row deep groove ball bearing (open/with dust cover/with seal optional), Material: Inner/outer ring: Chromium-molybdenum alloy steel (hardness HRC60-64), Balls: GCr15 high-carbon chromium bearing steel, Cage: Stamped steel plate (SPCC), Weight: Approximately 0.22 kg, Applicable Temperature: -40℃ to +120℃, Rated Speed: 3200 rpm, Limiting Speed: 4800 rpm, Lubrication Method: Grease lubrication (recommended Cat DEO-ULS 15W-40), Accuracy Class: ISO P0 (ABEC 1)

Key Dimensions
Inner Diameter: 50 mm (tolerance 0 to -0.012 mm), Outer Diameter: 80 mm (tolerance +0.010 to +0.020 mm), Width: 16 mm (tolerance ±0.10 mm) 8 mm diameter ball bearings, 13 balls, cage pitch circle diameter 65 mm, radial clearance C0 (0.015-0.035 mm), chamfer 1 mm × 45°, mating shaft diameter 50 mm (recommended transition fit H7/h6)

Compatible Machines and Applications: Compatible with Cat 320D, 323D, 336D excavators, 950M, 966M loaders. Used for hydraulic pump drive shaft support, gearbox input shaft bearing, fan pulley bearing, power steering pump bearing. Matching parts include bearing housing, retaining ring, and lock nut. Rated radial load ≥ 52 kN, rated axial load ≥ 14 kN, ultimate radial load ≥ 98 kN, ultimate axial load ≥ 28 kN

Performance Parameters: Contact angle 0°, sealing type optional: open type / ZZ metal dust cover / 2RS rubber seal ring, sealing rating IP54 (2RS type), grease filler 18 g. Fatigue life ≥ 8500 hours, impact load resistance ≥ 12 kN, radial runout ≤ 0.03 mm, axial runout ≤ 0.04 mm after installation.
Structural and Performance Advantages:

High versatility: The mature deep groove ball bearing structure is suitable for various rotating components, capable of withstanding medium radial loads and slight bidirectional axial loads, and suitable for various system conditions such as hydraulics, transmission, and cooling.

Smooth operation: The combination of GCr15 balls and a stamped cage results in low vibration and low noise (≤ 65 dB) at high speeds, meeting the stable operation requirements of medium and low speed equipment.

Convenient maintenance: Grease lubrication design eliminates the need for frequent grease replenishment after installation. The 2RS type comes with a built-in rubber seal, effectively blocking dust and moisture and extending maintenance intervals.

Simple installation: Standard sizes and transition fits allow for cold press-fitting (press-fitting force ≤ 18 kN), eliminating the need for special tooling and enabling quick assembly.

Installation and Maintenance Points:
**Before installation, clean the bearing, shaft diameter, and bearing housing bore, checking for burrs, cracks, and rust.** During press-fitting, apply force to the inner ring end face (when the inner ring mates with the shaft) or the outer ring end face (when the outer ring mates with the housing), avoiding stress on the balls. Ensure the bearing fits snugly against the shaft shoulder/housing shoulder, with radial runout ≤0.03 mm.

Run the bearing for 1 hour, checking that the temperature is ≤70℃ and there is no abnormal noise. Every 1000 hours of maintenance, check the seal condition and grease level. Replace the bearing if the seal is damaged, the grease is deteriorated, or the bearing clearance is >0.05 mm.

Prioritize original parts for replacement, ensuring material and dimensional accuracy to prevent premature bearing wear or seizing due to insufficient hardness or clearance deviation.