CAT 328-3230 Timing Gear Housing Ball Bearing

CAT 328-3230 is a Caterpillar single-row deep groove ball bearing (with dust cover, non-sealed), suitable for high-speed, light-load to medium-load parts such as excavator slewing bearings, loader gearboxes, and bulldozer hydraulic pumps. Its core advantages are high speed and low friction. It can withstand pure radial loads and also accommodate certain bidirectional axial loads, making it a highly efficient support component for rotating parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 328-3230, Type: Single-row deep groove ball bearing (with Z-type dust cover), Material: Bearing steel (GCr15, HRC60-64), Weight: Approx. 0.8 kg, Suitable Temperature: -40℃ to +120℃, Lubrication Method: Grease lubrication / Oil lubrication, Cage Material: Nylon 66, Sealing Type: Double-sided stamped steel plate dust cover (non-contact type)

Key Dimensions
Inner Diameter: 50 mm (Tolerance h6, 49.97-50.00 mm), Outer Diameter: 110 mm (Tolerance P0, 109.96-109.99 mm), Width: 27 mm (Tolerance ±0.1 mm), Number of Balls: 12, Ball Diameter: 16 mm, Radial Clearance: C3 (0.012-0.028 mm)

Applicable Models and Locations
Applicable Cat One slewing bearing is used for each of the following applications: 320D/323D excavator boom slewing bearing, 950GC loader gearbox input shaft, and D6K bulldozer hydraulic pump spindle. It primarily bears pure radial loads (maximum radial force ≤ 65 kN) and can withstand a small amount of bidirectional axial load (≤ 5 kN).

Performance Parameters: Rated dynamic load 65 kN, rated static load 42 kN, grease-lubricated limiting speed 5600 rpm, oil-lubricated limiting speed 6800 rpm, coefficient of friction ≤ 0.0015, allowable shaft misalignment relative to bearing housing ≤ 0.05°.

Structural and Performance Advantages:
High-speed compatibility: Deep groove ball bearing structure + nylon cage, low coefficient of friction, suitable for high-speed rotating components such as hydraulic pumps and gearboxes. The limiting speed is higher than that of tapered roller bearings, improving transmission efficiency.

Bidirectional axial load: Optimized groove design allows it to withstand a small amount of bidirectional axial load, handling slight axial movement of rotating components and preventing bearing seizure.

Dust Protection: Double-sided dust covers prevent dust and impurities from entering the bearing, reducing wear on rollers and raceways, extending maintenance intervals, and making it suitable for dusty outdoor environments.

Easy Installation: The integrated inner and outer ring design allows for direct press-fitting without the need for clearance adjustment (C3 pre-adjustment), resulting in high installation efficiency and reduced assembly error risks.

Installation and Maintenance Points: Before installation, clean the shaft diameter, bearing housing bore, and bearing. The shaft diameter surface roughness Ra ≤ 0.8 μm, free of burrs; cold press installation (pressure 8-10 MPa), ensuring the bearing end face fits snugly against the shaft shoulder, and tightening bolts to a torque of 80-90 N·m.

Maintenance Every 2500 Hours: Check bearing temperature (≤80℃), abnormal noise, and the integrity of the dust covers. If ball bearings are pitted or the cage is cracked, replace immediately; lubricate with Cat NLGI 2 lithium-based grease, filling the bearing cavity to 1/3-1/2 of its volume. Original parts should be preferred. Aftermarket parts may have problems such as insufficient ball bearing precision or insufficient cage strength, which can easily lead to large vibrations and shortened lifespan during high-speed operation, causing hydraulic pump and gearbox failures.