सिलिंड्रिकल रोलर बेयरिंग नामांकन: N, NU, NJ, NUP और NN
Cylindrical roller bearings use line contact between rollers and raceways, providing strong radial-load capacity for heavy-duty industrial equipment. Their designations normally begin with N, followed by the type, size series, bore code and optional suffixes.
Single-row type codes
| Code | Ring flange arrangement |
|---|---|
| N | Outer ring without flanges; inner ring has two flanges. |
| NU | Inner ring without flanges; outer ring has two flanges. |
| NJ | Inner ring has one flange; outer ring has two flanges. |
| NF | Outer ring has one flange; inner ring has two flanges. |
| NUP | Inner ring has one integral flange and a loose flange ring. |
Double-row types
NN and NNU identify common double-row cylindrical roller bearing arrangements. The appropriate type depends on the required axial location and the machine load path.
Size series and bore codes
Common series include 10, 12, 22 and 23 for single-row bearings, plus 30, 39 and 49 for double-row types. From bore code 04 upward, the bore is normally the code multiplied by 5 mm.
Example: NU2208E
NU means the inner ring has no flanges while the outer ring has two. 22 is the size series. 08 is a 40 mm bore. E identifies a reinforced design.
Useful suffixes
- E: reinforced design.
- Z: low-heat design.
- TB: roller-guided PPS resin cage.
- MB: brass cage guided by the inner ring.
- KR: tapered bore, 1:12 taper.
- E44: standard outer-ring lubrication groove and holes.
FAQ
Which is better, NU or NJ?
Neither is universally better. Select the type based on axial location requirements and the equipment load path.
Why does the cage matter?
Cage material and guidance influence speed capability, lubrication behavior and suitability for the operating environment.
Explore HX cylindrical roller bearings by model, cage material and precision grade.