1 Model Information & Technical Parameters

Model：N 1011 KTNHA/SP

 

Basic Dimensions

Parameter Value Unit

Bore diameter (d) 55 mm

Outside diameter (D) 90 mm

Width (B) 18 mm

Inner ring flange diameter (d₁) 68.2 mm

Outer ring raceway diameter (E) 81 mm

Chamfer dimension (r₁,₂ min.) 1.1 mm

Chamfer dimension (r₃,₄ min.) 0.6 mm

Permissible axial displacement (s max.) 2.5 mm

Bore type Tapered 1:12 —

Accuracy class SP（Super Precision） —

Radial internal clearance C1 —

Performance Data

Parameter Value Unit

Dynamic load rating (C) 39.1 kN

Static load rating (C₀) 46.5 kN

Fatigue load limit (Pᵤ) 5.2 kN

Reference speed 17,000 r/min

Limiting speed – grease 17,000 r/min

Limiting speed – oil-air 24,000 r/min

Axial static stiffness (guideline) 590 N/µm

Operating temperature range -30 ~ +110 °C

Technical Attributes

Attribute Detail

Bearing type Super-precision single row cylindrical roller bearing

Series N 10

Number of rows 1

Inner ring design Two flanges (integral ribs)

Outer ring design Flangeless (0 flanges)

Cage material Glass fibre reinforced PEEK, outer ring centred (TNHA) 

Roller material Bearing steel

Ring material Bearing steel

Seal type Open (no seals)

Bore type Tapered 1:12

Accuracy class SP

Radial clearance C1

Separable design Yes (inner and outer rings separable)

Design speed High

Logistics & Industry Codes

Parameter Value Unit

Net weight 0.38 kg

Indicative carbon footprint 1.4 kg CO₂e

eClass code 23-05-09-01 —

UNSPSC code 31171505 —

Suffix Full Explanation

Suffix Meaning

N Single row cylindrical roller bearing, two flanges on inner ring, flangeless outer ring

10 Dimension series (N10 series)

11 Bore size code – 55 mm (11 × 5 = 55 mm)

K Tapered bore, taper 1:12

TNHA Glass fibre reinforced PEEK cage, outer ring centred

SP Super Precision class – dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4

Important reminder: This model features a tapered bore (1:12) . During mounting, a lock nut or hydraulic nut is used to drive the bearing onto the tapered shaft journal, enabling precise adjustment of radial clearance. 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 SP accuracy class ensures extremely high running accuracy. The two-flange inner ring and flangeless outer ring (N-type) allow the bearing to accommodate axial displacement in both directions (max. 2.5 mm), effectively compensating for thermal expansion. This bearing type is commonly used as a floating bearing.

 

2 Structure & Operating Characteristics

The NMT N 1011 KTNHA/SP is a super-precision single row cylindrical roller bearing (N-type) , specifically developed for high-speed, high-precision spindle applications. This bearing achieves an excellent balance between load capacity, speed and accuracy.

 

Single row roller design is the structural foundation. Single row cylindrical rollers with line contact between rollers and raceways provide high radial load capacity (dynamic load 39.1 kN, static load 46.5 kN) and low friction characteristics. Compared to full-complement cylindrical roller bearings, the caged design allows higher speeds with less frictional heat generation, making it particularly suitable for high-speed rotation (oil-air limiting speed up to 24,000 r/min).

 

Two-flange inner ring and flangeless outer ring (N-type design) allow the bearing to accommodate axial displacement in both directions, with maximum permissible axial displacement of 2.5 mm, effectively compensating for thermal expansion. The bearing itself does not carry axial loads; axial displacement is accommodated by the external structure. Therefore, N-type bearings are commonly used as floating bearings.

 

Glass fibre reinforced PEEK cage (TNHA suffix) is a key technological feature. PEEK (polyetheretherketone) is a high-performance engineering plastic offering:

 

Excellent heat resistance: Far exceeding nylon cages in high-temperature performance

 

Superior dimensional stability: Glass fibre reinforcement significantly enhances rigidity and strength

 

Low friction and self-lubrication: Reduces friction with rollers and minimizes heat generation

 

Outer ring centred design: Cage guided by the outer ring, maintaining roller positioning accuracy at ultra-high speeds while optimizing lubricant effectiveness and preventing lubricant starvation at high speeds

 

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

 

SP Super Precision class is the hallmark of NMT super-precision bearings – dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4 – ensuring extremely high running accuracy and low vibration levels.

 

3 Core Performance Advantages

1. Perfect balance of high radial load capacity and low friction. Single row cylindrical roller line contact structure provides high radial load capacity (dynamic load 39.1 kN, static load 46.5 kN) while maintaining low friction characteristics, suitable for high-speed rotation.

 

2. PEEK cage (TNHA) – stability at high speeds. Glass fibre reinforced PEEK cage offers excellent heat resistance and dimensional stability. Outer ring centred design ensures roller positioning accuracy at ultra-high speeds.

 

3. Super-precision running accuracy (SP). Dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4, ensuring ultra-low vibration, ultra-low noise and ultra-low heat generation to meet high-precision machining requirements.

 

4. Bidirectional axial displacement compensation (max. 2.5 mm). The two-flange inner ring and flangeless outer ring design allow the bearing to accommodate axial displacement in both directions during operation, effectively compensating for thermal expansion. This bearing is commonly used as a floating bearing.

 

5. Tapered bore mounting with precisely adjustable clearance. 1:12 tapered bore enables precise radial clearance 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, greatly simplifying assembly and disassembly.

 

7. Excellent high-speed performance. Grease limiting speed: 17,000 r/min; oil-air limiting speed: 24,000 r/min, meeting high-speed spindle requirements.

 

4 Typical Application Fields

This bearing is suitable for large and medium electric motors, rolling stock, machine tool spindles, internal combustion engines, generators, gas turbines, gearboxes, rolling mills, vibrating screens, and lifting and transport machinery.

 

4.1 High-Speed Machine Tool Spindles

High-speed machining center spindles, high-speed milling spindles, high-speed grinding spindles – the combination of high precision and high speed is a perfect match.

 

4.2 Precision Grinding Machines

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

 

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 Electric Motors and Generators

Large and medium electric motors, generators – stable performance under heavy loads and high speeds.

 

4.6 Industrial Machinery and Automation

Gearboxes, rolling mills, vibrating screens, lifting and transport machinery; robotics and automation system rotary supports.

 

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. Maximum permissible axial displacement is 2.5 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 17,000 r/min; oil-air limiting speed is 24,000 r/min. The PEEK cage has stringent lubrication requirements – high-quality synthetic grease or specialized high-speed spindle 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. 2.5 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.