Manufactured by CHG Bearing, the NNU 4944 BK/SPW33 is a precision Super-Precision Cylindrical Roller Bearings. Key dimensional parameters include a 220 mm bore diameter, a 300 mm outer diameter, and a 80 mm overall width. This component is designed to meet standard load requirements and ensure consistent operational performance. For comprehensive technical evaluation, please explore the detailed specifications, dimensional data, product images, and CAD drawings provided below. A complete PDF data sheet is also readily available for direct download to support your engineering and procurement needs.
NNU 4944 BK/SPW33 - Super-Precision Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU 4944 BK/SPW33 |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Super-precision Cylindrical Roller Bearing |
| Design Type | Tapered Bore 1:12 |
| Structure (Drawing Reference) | Complete Bearing |
| Number of Rows | 2 |
| Ring Type | None |
| Design | NNU Design |
| Tolerance Class | SP |
| Bearing Material | Bearing Steel |
| Coating | None |
| Sealing | None |
| Lubricant | None |
| Features | Annular Lubrication Groove and Lubrication Holes |
| Number of Flanges – Outer Ring | 3 |
| Number of Ribs – Inner Ring | 0 |
| Dimensions | |
| Bore Diameter (d) | 220 mm |
| Width (B) | 80 mm |
| Outer Diameter (D) | 300 mm |
| Minimum Chamfer Dimension rmin | 2 mm |
| Inner Ring Chamfer | 2.1 mm |
| Outer Ring Chamfer | 1.1 mm |
| End-face Height Difference h | 3.7 mm |
| Outer-Ring Land Diameter (L2 / D1) | 272.2 mm |
| Inner Ring Raceway Diameter F | 245 mm |
| Shaft Shoulder Diameter dₐ, min. | 231 mm |
| Shaft Shoulder Diameter dₐ, max. – NNU Design | 242 mm |
| Housing Shoulder Diameter Dₐ, max. | 289 mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 512 kN |
| Basic Static Load Rating C₀ (kN) | 1140 kN |
| Limiting Speed – Grease (r/min) | 2400 r/min |
| Limiting Speed – Oil-air (r/min) | 2800 r/min |
| Reference Grease Quantity Gref (cm³) | 150 cm³ |
| Fatigue Load Limit Pᵤ (kN) | 114 kN |
| Axial Static Stiffness – Guideline Value (N/µm) | 5990 N/µm |
| Material | |
| Lubrication Groove Width | 11.1 mm |
| Lubrication Holes (qty × Ø mm) | 3 |
| Weight (kg) | 16 kg |
| Radial Internal Clearance | C1 mm |
| Internal Design & Weight | |
| Cage Type | Machined Metal Cage |
| Mounting Dimensions | |
| Lubrication Port Thread / Size Φ1 | 247 |
NNU 4944 BK/SPW33 300 mm 220 mm 80 mm Frequently Asked Questions about NNU 4944 BK/SPW33 Super-Precision Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
Each NNU 4944 BK/SPW33 produced in CHG Bearing manufacturing facilities features accurately profiled corner chamfers complying with DIN 5412 / ISO standard corner radii. When designing mating shafts and housing shoulders, machining an undercut or fillet radius strictly within the inner ring clearance limit (220 mm bore side) ensures perfect planar contact without edge binding.
Sourcing NNU 4944 BK/SPW33 directly from CHG Bearing eliminates intermediate brokerage markups while granting you factory-direct engineering backup, rigorous ISO-certified quality assurance, competitive volume wholesale pricing, and dependable supply chain stability for Super-Precision Cylindrical Roller Bearings.
Following standard ISO 281 fatigue calculation guidelines, the nominal rating life (L10) of CHG Bearing NNU 4944 BK/SPW33 correlates its dynamic capacity (standard dynamic) with equivalent dynamic loads. In controlled industrial settings with proper contamination-free filtration, field data confirms continuous operational longevity exceeding 20,000 to 50,000 service hours.
To safeguard CHG Bearing NNU 4944 BK/SPW33 against fretting wear and false brinelling during transport or vibration, assemble mating surfaces (220 mm x 300 mm) using anti-fretting mounting paste. Maintaining strict alignment and avoiding prolonged static vibration will preserve raceway polish.
