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NNU4938 Double Row Cylindrical Roller Bearing 190x260x69mm
- Extreme Radial Rigidity: Double row roller arrangement distributes immense radial forces across maximum raceway surface area.
- Axial Displacement Capability: Flangeless inner ring permits free thermal expansion and contraction of shafts without creating axial preloads.
- Low Section Height: Compact radial cross-section allows large shaft diameters inside space-restricted machinery housings.
- High Precision Running: Precision-ground rollers ensure smooth rotation with minimal radial runout under high speeds.
Technical Data
| Technical Parameter | Metric Value |
| Inner Bore Diameter (d) | 190.00 mm |
| Outer Diameter (D) | 260.00 mm |
| Total Width (B) | 69.00 mm |
| Precision Standard | ISO P6 / P5 / P4 |
Product Specifications
| Specification | Details |
| Item Type | Double Row Cylindrical Roller Bearing |
| Model Number | NNU4938 |
| Design Type | NNU Design (Outer Ring Flanged / Inner Ring Smooth) |
| Material | Top-Grade Vacuum-Degassed GCr15 Steel |
| Radial Rigidity | Exceptionally High Double-Row Roller Configuration |
Product Introduction
The NNU4938 is an extra-large, high-precision double-row cylindrical roller bearing engineered for applications demanding maximum radial stiffness, compact radial section, and high load capacity. Featuring a 190 mm inner bore, 260 mm outer diameter, and 69 mm width, the "NNU" design features a solid outer ring with double integral flanges and a smooth flangeless inner ring, allowing axial displacement of the shaft relative to the housing. Manufactured from top-tier GCr15 bearing steel with precision-ground rollers, the NNU4938 is a critical component for heavy machine tool spindles, steel rolling mills, and large industrial drive gearboxes.
Applications
Heavy machine tool main spindles and lathe headstocks.
Steel rolling mill stands and wire rod reduction machinery.
Large industrial gearboxes, presses, and heavy plastic extruders.
FAQ
Q: Does the NNU4938 bearing handle axial thrust loads?
A: No, NNU design cylindrical roller bearings are designed strictly for radial loads and accommodating axial shaft expansion. Axial loads must be supported by a secondary thrust bearing.
Q: Can this bearing be supplied with a tapered bore (NNU4938K)?
A: Yes, we can supply both cylindrical bore (NNU4938) and 1:12 tapered bore (NNU4938K) configurations upon request.
OEM & Custom Service
Complete B2B OEM capabilities including high-precision grades (P5/P4), custom radial internal clearance settings, laser engraving, and custom heavy-duty ocean freight packaging.
Packing & Delivery
Coated thoroughly with heavy anti-rust oil, heat-sealed in thick VCI protective plastic bags, and bolted securely inside reinforced wooden export crates.
