Manufactured by CHG Bearing, the NNU 4940 BK/SPW33 is a precision Super-Precision Cylindrical Roller Bearings. Key dimensional parameters include a 200 mm bore diameter, a 280 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 4940 BK/SPW33 - Super-Precision Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NNU 4940 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) | 200 mm |
| Width (B) | 80 mm |
| Outer Diameter (D) | 280 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) | 252.2 mm |
| Inner Ring Raceway Diameter F | 225 mm |
| Shaft Shoulder Diameter dₐ, min. | 211 mm |
| Shaft Shoulder Diameter dₐ, max. – NNU Design | 222 mm |
| Housing Shoulder Diameter Dₐ, max. | 269 mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 484 kN |
| Basic Static Load Rating C₀ (kN) | 1040 kN |
| Limiting Speed – Grease (r/min) | 2600 r/min |
| Limiting Speed – Oil-air (r/min) | 3000 r/min |
| Reference Grease Quantity Gref (cm³) | 117 cm³ |
| Fatigue Load Limit Pᵤ (kN) | 106 kN |
| Axial Static Stiffness – Guideline Value (N/µm) | 5480 N/µm |
| Material | |
| Lubrication Groove Width | 11.1 mm |
| Lubrication Holes (qty × Ø mm) | 3 |
| Weight (kg) | 15.1 kg |
| Radial Internal Clearance | C1 mm |
| Internal Design & Weight | |
| Cage Type | Machined Metal Cage |
| Mounting Dimensions | |
| Lubrication Port Thread / Size Φ1 | 227 |
NNU 4940 BK/SPW33 280 mm 200 mm 80 mm Frequently Asked Questions about NNU 4940 BK/SPW33 Super-Precision Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
As standard production, CHG Bearing subjects NNU 4940 BK/SPW33 to precision bainite or martensite quenching, offering dimensional stability up to 120°C (248°F). For high-heat processing equipment, CHG Bearing also supplies custom S0 (150°C), S1 (200°C), or S2 (250°C) stabilization heat treatments upon request to prevent residual austenite transformation.
When fitting NNU 4940 BK/SPW33 over a 200 mm shaft, CHG Bearing strictly recommends uniform induction heating (controlled between 90°C and 110°C) or precision hydraulic press sleeves. Under no circumstances should direct impact blows be struck against the rings or cage, as shock loads cause brinelling indents and premature spalling.
Built for demanding industrial environments, the NNU 4940 BK/SPW33 Super-Precision Cylindrical Roller Bearings by CHG Bearing boasts a dynamic load rating (Cr) of standard dynamic and a static load threshold (C0r) of standard static. The optimized internal raceway geometry balances stress distribution, mitigating edge loading even when operating under peak mechanical stresses.
Every production batch of CHG Bearing NNU 4940 BK/SPW33 Super-Precision Cylindrical Roller Bearings comes with complete traceability. Upon shipment, CHG Bearing can provide EN 10204 3.1 Material Test Reports (MTR), Certificates of Conformity (CoC), spectral chemical composition analysis, and dimensional inspection sheets.
