1 Model Information & Technical Parameters

Model：NN 3010 KTN/UP

 

Basic Dimensions

Parameter Value Unit

Bore diameter (d) 50 mm

Outside diameter (D) 80 mm

Width (B) 23 mm

Inner ring flange diameter (d₁) 61.3 mm

Outer ring raceway diameter (E) 72.5 mm

Chamfer dimension (r₁,₂ min.) 1.0 mm

Chamfer dimension (r₃,₄ min.) 0.6 mm

Permissible axial displacement (s max.) 1.5 mm

Bore type Tapered 1:12 —

Tolerance class UP (dimensional accuracy P4, running accuracy higher than P4) —

Radial internal clearance C1 —

Performance Data

Parameter Value Unit

Dynamic load rating (C) 52.8 kN

Static load rating (C₀) 73.5 kN

Fatigue load limit (Pᵤ) 8.5 kN

Limiting speed – grease 11,000 r/min

Limiting speed – oil-air 13,000 r/min

Operating temperature range -30 ~ +110 °C

Bore diameter tolerance 0 ~ +0.012 mm

Outside diameter tolerance -0.009 ~ 0 mm

Width tolerance -0.12 ~ 0 mm

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 injection moulded cage, roller centred

Roller material Chrome steel

Ring material Chrome steel

Seal type Open (no seals)

Bore type Tapered 1:12

Tolerance class UP

Radial clearance C1

Separable design Yes (inner and outer rings separable)

Logistics & Industry Codes

Parameter Value Unit

Net weight 0.383 (≈0.4) kg

eClass code 23-05-09-01 —

UNSPSC code 31171505 —

Suffix Full Explanation

Suffix Meaning

NN Double row cylindrical roller bearing, high precision series

30 Dimension series (ISO series 30)

10 Bore size code – 50 mm (10 × 5 = 50 mm)

K Tapered bore, taper 1:12

TN PA66 nylon injection moulded cage, roller centred

UP Ultra-super-precision class – dimensional accuracy approx. P4, running accuracy higher than P4

Important reminder: This model features a tapered bore (1:12) . During mounting, a lock nut or withdrawal sleeve is used to drive the bearing onto the tapered shaft journal, enabling precise adjustment of radial clearance or preload. The bearing is open-type without seals and requires external lubrication and sealing protection based on actual operating conditions. Operating temperature range: -30°C to +110°C. The separable design allows independent mounting of inner and outer rings, facilitating assembly and maintenance. The UP accuracy class (dimensional accuracy P4, running accuracy higher than P4) is among the highest precision grades for double row cylindrical roller bearings, far exceeding SP grade. 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 3010 KTN/UP is a super-precision double row cylindrical roller bearing from the NN 30 series, specifically developed for ultra-high-precision applications such as advanced machine tool spindles. This series achieves a unique balance between load carrying capacity, rigidity and accuracy.

 

Double row roller design is the core structural feature. Two rows of rollers arranged in parallel distribute loads more evenly across a wider area, offering higher load capacity and rigidity compared to single row bearings. 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.

 

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.

 

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 (TN suffix) ensures precise roller positioning and stability at high speeds. PA66 material offers excellent wear resistance and low friction characteristics, effectively reducing heat generation and energy consumption. The cage prevents cylindrical rollers from contacting each other, enabling controlled motion of rolling elements with lower friction, thus achieving higher speeds and reduced heat generation.

 

Tapered bore (1:12) design enables precise radial clearance or preload adjustment through axial advancement during mounting, critical for optimizing spindle system rigidity and accuracy.

 

UP tolerance class is the highest precision grade among NMT super-precision bearings. UP class bearings achieve dimensional accuracy approximately at P4 level and running accuracy higher than P4, far exceeding SP grade (dimensional accuracy P5, running accuracy P4). This precision grade ensures ultimate running accuracy and ultra-low vibration levels to meet nano-level machining requirements.

 

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 52.8 kN; static load rating reaches 73.5 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 ultra-high-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. UP top precision class – ultimate assurance for ultra-high-precision machining. UP class dimensional accuracy approx. P4, running accuracy higher than P4, far exceeding SP grade, ensuring ultra-low vibration, ultra-low noise and ultra-low heat generation to meet nano-level machining accuracy requirements.

 

5. Tapered bore mounting with precisely adjustable clearance. 1:12 tapered bore enables precise radial clearance or preload adjustment through axial advancement during mounting, optimizing system rigidity.

 

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

 

7. Low friction, high efficiency and extended service life. Advanced materials and manufacturing techniques ensure minimal friction, reduced heat generation and extended service life. PA66 cage effectively reduces friction and energy consumption.

 

4 Typical Application Fields

4.1 Ultra-High-Precision Machine Tool Spindles

Ultra-precision machining center spindles, nano-level turning center spindles, ultra-precision milling spindles – UP class precision ensures sub-micron machining quality.

 

4.2 Ultra-Precision Grinding Machines

Ultra-precision external cylindrical grinder spindles, ultra-precision internal grinder spindles – extremely high radial load capacity and running accuracy ensure mirror-quality machining.

 

4.3 Aerospace Engines and Gas Turbines

Aircraft engine main shafts, gas turbine rotor supports – high strength and reliability meet aerospace requirements.

 

4.4 High-Performance Automotive and Racing

High-performance automotive transmissions, racing gearboxes, high-speed drive units.

 

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 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 taper (1:12) and dimensional accuracy against design specifications. Prepare appropriate mounting tools such as lock nuts or hydraulic nuts.

 

5.2 Installation Procedure

This bearing features a tapered bore (1:12) . During mounting, the bearing must be driven onto the tapered shaft journal. Use a lock nut or hydraulic nut to apply axial advancement force, precisely adjusting radial clearance by controlling advancement distance. Never apply force through rolling elements or cage. Monitor radial clearance changes throughout installation until the target clearance value (corresponding to C1 clearance class) is achieved. The separable design allows independent mounting of inner and outer rings.

 

5.3 Clearance Adjustment Instructions

Radial clearance of tapered bore bearings decreases as axial advancement increases. During mounting, use feeler gauges or dial indicators to monitor clearance changes, ensuring clearance is adjusted to the design target. C1 clearance is suitable for high-speed operation and precision positioning applications. Maximum permissible axial displacement is 1.5 mm.

 

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 11,000 r/min; oil-air limiting speed is 13,000 r/min. High-quality spindle grease or circulating oil is recommended. Open construction requires reliable sealing protection at the equipment level. Establish regular lubrication replenishment schedule; dry running is strictly forbidden.

 

5.5 Environmental Considerations

Operating temperature range: -30°C to +110°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.

 

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.