CAT 302-6780 Single Row Ball Bearing

CAT 302-6780 is a Caterpillar single-row deep groove ball bearing, suitable for the gearboxes, final drives, or hydraulic pumps of excavators and loaders. It is designed to withstand radial loads and allow a certain amount of axial displacement, making it suitable for medium- and high-speed and medium- and light-load conditions. It features low friction, high speed adaptability, and long service life, and is a key component for the stable operation of the transmission system. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 302-6780, Type: Single-row deep groove ball bearing (open/iron cap seal optional), Material: Bearing steel (GCr15, quenching hardness HRC 60-64), Cage: Stamped steel plate (anti-jamming), Single weight: Approximately 0.82 kg, Operating temperature: -40℃ to +120℃, Lubrication method: Grease lubrication (lithium-based grease recommended), Design life: ≥12000 hours (normal operating conditions)

Key Dimensions
Inner diameter: 65 mm (tolerance 0/+0.013 mm), Outer diameter: 120 mm (tolerance 0/-0.015 mm), Width: 23 mm (tolerance 0/-0.02 mm), Ball diameter: 12.7 mm, Number of balls: 10, Radial clearance: C3 grade (0.015-0.035 mm), Chamfer size: r1=1.5 mm
Compatible Models and Parts: Compatible with Cat 320D2 and 330D2 excavators (final drive output shaft), 950M loader (transmission shaft), 3516 hydraulic pump (drive shaft), and compatible with 203-0711 retainer, 103-8329 elastic retaining ring, and 5P-0960 grease.

Performance Parameters: Basic rated dynamic load 55 kN, basic rated static load 38 kN, limiting speed (grease lubrication) 5600 r/min, reference speed (oil lubrication) 7000 r/min, coefficient of friction ≤0.0015, impact load ≥15 kN.

Structural and Performance Advantages: Single-row deep groove ball bearing structure, capable of simultaneously bearing radial loads and bidirectional small axial loads, suitable for medium and high speed operating conditions. GCr15 bearing steel with quenching treatment provides excellent wear resistance and fatigue resistance, reducing transmission system friction loss and improving efficiency.

The stamped steel cage features evenly distributed steel balls, ensuring smooth operation and effectively suppressing vibration and noise. It is suitable for high-speed equipment operation. The open design facilitates lubrication replenishment, while the sealed version (iron cover) prevents dust and foreign object intrusion, making it suitable for harsh outdoor conditions.

Standard radial clearance is C3 grade, accommodating thermal expansion and contraction during operation and preventing high-temperature seizure. It is suitable for components with large temperature fluctuations, such as gearboxes and hydraulic pumps, ensuring long-term stable operation.

Installation and Maintenance Points: Before installation, clean the bearing, shaft diameter, and bearing housing, checking for burrs and rust. Measure the shaft diameter and inner diameter, and the bearing housing and outer diameter, ensuring an interference fit of 0.005-0.01 mm (cold press installation). Do not strike the bearing end face. Use a special tool to press in evenly to avoid cage deformation.

After installation, rotate the shaft system to check for jamming and abnormal noise. Add sufficient lithium-based grease (filling volume is 1/3-1/2 of the bearing cavity). When installing the sealed version, pay attention to the sealing direction to prevent grease leakage.

Maintenance: Check the lubrication status and clearance every 1500 hours. If abnormal noise, abnormal temperature, or excessive clearance occurs, replace immediately. Replace in pairs (on the same shaft end). Do not mix bearings of different models or brands.