NJ2311EM Cylindrical Roller Bearing for Industrial Machinery & Automotive Use
The NJ2311EM cylindrical roller bearing is a precision-engineered component known for robustness, durability, and high performance. It meets modern industrial demands, ensuring smooth machinery operation. This introduction covers its design, performance, materials, applications, and maintenance.
I. Design and Structure
Inner Ring and Outer Ring
The inner ring, with a single-side double-flange, has a near-mirror finish, fitting a 55mm shaft snugly for efficient power transfer and minimal slippage. The outer ring, flange-less, is 120mm in diameter and 43mm wide, built to withstand heavy radial loads.
The inner ring's double-flange guides cylindrical rollers for stable rotation under dynamic loads and allows handling some one-way axial load, beneficial in applications with axial forces.
Rolling Elements and Cage
Precision-manufactured cylindrical rollers, from high-grade bearing steel, have a surface roughness under Ra0.1μm, reducing friction. Their cylindrical shape and well-designed raceways enable handling heavy radial loads via even line contact.
The brass (CuZn37) cage dissipates heat efficiently, suits medium to high speeds, maintains roller spacing to prevent collisions, and guides rollers along raceways, boosting performance.
Sealing Structure (Optional)
Optional seals adapt to environments: nitrile rubber contact seals block contaminants in dusty/humid settings; non-contact labyrinth seals allow up to 5000rpm for high-speed, low-friction needs.
II. Key Parameters
| Parameter |
Value |
| Inner Diameter (d) |
55mm |
| Outer Diameter (D) |
120mm |
| Width (B) |
43mm |
| Basic Dynamic Load Rating (Cr) |
128kN |
| Basic Static Load Rating (Cor) |
118kN |
| Limiting Speed (Grease Lubrication) |
4000rpm |
| Limiting Speed (Oil Lubrication) |
5000rpm |
III. Performance Advantages
High Radial Load-Carrying Capacity
With a 128kN dynamic and 118kN static load rating, it handles heavy radial loads in large conveyors and medium-heavy machinery gearboxes, resisting fatigue.
Axial Load Accommodation
The inner ring's design allows one-way axial load handling, reducing stress on shafts and components in motors and machinery with axial forces.
Low Friction and High-Speed Capability
A 0.002 friction coefficient cuts energy use. It reaches 4000rpm (grease) and 5000rpm (oil), fitting high-speed equipment like machine tool spindles.
Good Wear Resistance
Made of GCr15 steel, heat-treated to HRC60-65, with surface treatments, it endures wear in tough conditions.
IV. Material Quality
Material of Rings and Rollers
High-purity GCr15 steel, vacuum-degassed to remove flaws, ensures density and strength. Rollers undergo cold heading and tempering for uniform structure and over 10J/cm² impact toughness.
Cage Material
Brass (CuZn37) offers thermal conductivity for heat dissipation and strength to withstand operational forces, keeping rollers aligned.
V. Application Fields
Industrial Machinery
Used in large lathe drive shafts and heavy-duty conveyor rollers/pulleys, supporting cutting loads and ensuring smooth material transport.
Electric Motors
Fits medium-high power motors, withstanding radial forces and thermal expansion-induced axial movement, enhancing efficiency and lifespan.
Automotive Industry
Suitable for vehicle differentials and large engine water pumps, handling complex loads and harsh conditions.
VI. Installation and Maintenance
Install with hydraulic presses or specialized tools to avoid misalignment. Tapered shaft installations use lock nuts for position/preload adjustment.
Lubricate with lithium-based grease (1/3-1/2 fill) or ISO VG 32/46 oil (0.1-0.3MPa for forced systems).
Monitor temperature (≤70°C), check for vibration/noise. Disassemble with pullers to avoid damage. Regular maintenance prevents failures.
VII. Conclusion
The NJ2311EM bearing combines strength, load capacity, and adaptability, performing reliably in diverse conditions. It's vital for industrial machinery, motors, and automotive systems, driving efficiency across industries.
