1 Model Information & Technical Parameters

Model：NN 3009 TN/SP

 

Basic Dimensions

Parameter Value Unit

Bore diameter (d) 45 mm

Outside diameter (D) 75 mm

Width (B) 23 mm

Inner ring flange diameter (d₁) 56.3 mm

Outer ring raceway diameter (E) 67.5 mm

Fillet radius (r₁,₂ min.) 1.0 mm

Permissible axial displacement (s max.) 1.5 mm

Bore type Cylindrical —

Accuracy class SP (dimensional accuracy P5, running accuracy P4) —

Internal clearance C1 —

Performance Data

Parameter Value Unit

Dynamic load rating (C) 50.1 kN

Static load rating (C₀) 65.5 kN

Fatigue load limit (Pᵤ) 7.65 kN

Limiting speed – grease 12,000 r/min

Limiting speed – oil 14,000 r/min

Reference speed – grease 11,000 r/min

Reference speed – oil 13,000 r/min

Axial static stiffness (guideline) 940 N/µm

Reference grease quantity 2.4 cm³

Operating temperature range -30 ~ +120 (typical) °C

Technical Attributes

Attribute Detail

Bearing type Super-precision double row cylindrical roller bearing

Series NN 30

Number of rows 2

Inner ring design Three flanges (integral ribs)

Outer ring design Flangeless

Cage material PA66 (nylon 66) injection moulded cage, roller centred

Roller material Bearing steel (chrome steel)

Seal type Open (no seals)

Bore type Cylindrical

Accuracy class SP

Internal clearance C1

Separable design Yes (inner and outer rings separable)

Logistics & Industry Codes

Parameter Value Unit

Net weight 0.38 kg

eClass code 23-05-08-03 (reference) —

UNSPSC code 31171504 (reference) —

Suffix Explanation

NN: Double row cylindrical roller bearing, high precision series

 

30: Dimension series (ISO series 30)

 

09: Bore size code – 45 mm (09 × 5 = 45 mm)

 

TN: Injection moulded cage (PA66 nylon 66), roller centred

 

SP: Super Precision accuracy class – dimensional accuracy approx. P5, running accuracy approx. P4

 

Important reminder: This model features a cylindrical bore and can be mounted directly on cylindrical shafts. The bearing is open-type without seals and requires external lubrication and sealing protection based on actual operating conditions. Typical operating temperature range: -30°C to +120°C. The separable design allows independent mounting of inner and outer rings, facilitating assembly and maintenance. SP accuracy class ensures extremely high running accuracy and low vibration levels. The three-flange inner ring and flangeless outer ring allow the bearing to accommodate axial displacement in both directions (max. 1.5 mm), effectively compensating for thermal expansion.

 

2 Structure & Operating Characteristics

The NMT NN 3009 TN/SP is a super-precision double row cylindrical roller bearing from the NN 30 series, specifically developed for high-precision, high-rigidity applications such as machine tool spindles. This series achieves a unique balance between load carrying capacity, rigidity and speed.

 

Double row roller design is the core structural feature. Two rows of rollers arranged in parallel distribute loads more evenly across a wider area, significantly increasing the contact area between rollers and raceways. The line contact between cylindrical rollers and raceways provides high radial load capacity, enabling the bearing to accommodate heavy loads and impact loads while also supporting high-speed rotation. Compared to single row bearings, the double row design offers higher load capacity and rigidity.

 

Three-flange inner ring and flangeless outer ring design is another key feature. The inner ring features three integral ribs (flanges) while the outer ring has no flanges, allowing the bearing to accommodate axial displacement in both directions. In applications with significant thermal expansion such as machine tool spindles, thermal elongation of the shaft and housing can be compensated through internal axial displacement, with maximum permissible axial displacement of 1.5 mm, without generating additional axial loads.

 

Separable design enables independent mounting of inner and outer rings, which is particularly convenient in interference fit applications – one ring can be mounted first, then the other assembled, greatly simplifying assembly and disassembly.

 

PA66 nylon injection moulded cage (suffix TN) ensures precise roller positioning and stability at high speeds. The cage effectively prevents cylindrical rollers from contacting each other, enabling controlled motion of rolling elements with lower friction, thus achieving higher speeds and reduced heat generation. PA66 material combines light weight with excellent wear resistance.

 

SP Super Precision class is the hallmark of NMT super-precision bearings. SP class bearings achieve dimensional accuracy approximately at P5 level and running accuracy approximately at P4 level, ensuring extremely high running accuracy and low vibration levels to meet high-precision machining requirements.

 

Cylindrical bore design allows direct mounting on cylindrical shafts, with simple installation suitable for most standard spindle configurations.

 

3 Core Performance Advantages

1. Extremely high radial load capacity. Double row roller design and cylindrical roller line contact structure enable the bearing to withstand very high radial and impact loads. Dynamic load rating reaches 50.1 kN; static load rating reaches 65.5 kN.

 

2. Superior system rigidity. The unique double row compact configuration of the NN 30 series provides exceptionally high radial stiffness, making it ideal for precision spindle systems.

 

3. Bidirectional axial displacement compensation. The three-flange inner ring and flangeless outer ring design allow the bearing to accommodate axial displacement in both directions during operation, with maximum permissible axial displacement of 1.5 mm, effectively compensating for thermal expansion.

 

4. Super-precision running accuracy. SP accuracy class (dimensional accuracy P5, running accuracy P4) ensures low vibration, low noise and low heat generation, meeting high-precision machining requirements.

 

5. Separable design for easy assembly and maintenance. Inner and outer rings can be mounted independently, particularly suitable for complex assembly conditions requiring interference fit, greatly simplifying maintenance and replacement.

 

6. PA66 nylon cage for excellent high-speed performance. Grease limiting speed: 12,000 r/min; oil limiting speed: 14,000 r/min, meeting high-speed spindle requirements. The cage effectively reduces friction and heat generation.

 

7. High precision manufacturing with international standard interchangeability. Manufactured from high-quality bearing steel with SP accuracy class, fully interchangeable with SKF NN 3009 TN/SP and other equivalent international brand models.

 

4 Typical Application Fields

4.1 Machine Tool Spindles

Machining center spindles (horizontal and vertical), turning center spindles, milling spindles – the combination of high rigidity, high accuracy and high speed is a perfect match.

 

4.2 Precision Grinding Machines

External cylindrical grinder spindles, internal grinder spindles, surface grinder spindles – extremely high radial load capacity and running accuracy ensure machining quality.

 

4.3 High-Speed Milling and Boring Equipment

High-speed milling machines, boring machines, drilling machine spindles – excellent speed performance meets high-speed cutting demands.

 

4.4 Gear Processing Equipment

Gear hobbing machines, gear shaping machine spindles – stable performance under heavy loads and impact loads.

 

4.5 Medical Equipment

MRI and other advanced imaging equipment rotating components – low friction and high running accuracy meet the stringent reliability requirements of medical devices.

 

4.6 Aerospace and High-Performance Automotive

Aircraft engine components, high-performance automotive transmission systems – critical applications requiring both robustness and precision.

 

4.7 Robotics and Automation Systems

High-precision positioning units, automation system rotary supports – high rigidity support ensures motion accuracy.

 

5 Assembly Specifications & Usage Guidelines

5.1 Pre-installation Inspection

Verify model and specifications match design requirements. Inspect bearing appearance to ensure no damage, corrosion or foreign matter. Check shaft dimensional accuracy against design specifications (cylindrical bore design suitable for cylindrical shafts). Prepare appropriate mounting tools.

 

5.2 Installation Procedure

This bearing features a cylindrical bore and can be mounted directly on cylindrical shafts. Use press-fit method or shrink-fit method for installation, with force applied evenly to the end face of the fitted ring. Never apply force through rolling elements or cage. The separable design allows independent mounting of inner and outer rings – the outer ring can be mounted in the housing first, then the inner ring on the shaft, or vice versa.

 

5.3 Installation Notes

For NN-type bearings (three-flange inner ring, flangeless outer ring), special attention is required during installation: the flangeless outer ring means the outer ring can slide freely axially in the housing. Ensure that axial positioning of the housing is provided by other components (such as end covers, spacers, etc.). Maximum permissible axial displacement is 1.5 mm – sufficient axial clearance must be预留 in the design.

 

5.4 Lubrication Maintenance

This model comes without pre-filled grease – lubricant must be added during installation based on operating conditions. Grease limiting speed is 12,000 r/min; oil limiting speed is 14,000 r/min. High-quality spindle grease or circulating oil is recommended. Reference grease quantity is 2.4 cm³. Open construction requires reliable sealing protection at the equipment level. Establish regular lubrication replenishment schedule; dry running is strictly forbidden.

 

5.5 Environmental Considerations

Typical operating temperature range: -30°C to +120°C. As this bearing is open construction, in dusty environments or coolant splash conditions, labyrinth seals or contact seals must be provided at the equipment level. The bearing itself does not carry axial loads; axial displacement (max. 1.5 mm) is accommodated by the external structure. Ensure that axial displacement does not cause interference between the bearing and other components.

 

6 Fault Identification

Common failure modes: Roller or raceway fatigue pitting, abnormal operating noise increase, significant rotation resistance increase, excessive temperature rise, seizure caused by poor lubrication. If cage deformation or rolling element damage occurs, replace the entire bearing assembly – repair and reuse are not allowed. Regularly monitor bearing temperature and vibration for early detection of abnormalities.