Needle roller bearings

Needle roller bearings utilise slender needle rollers as rolling elements. With their small diameter, they feature a highly compact radial design; their radial dimensions are significantly smaller than those of other bearings with the same inner diameter. They offer high radial load-carrying capacity but are virtually incapable of withstanding axial loads, making them suitable for applications where radial installation space is limited.

Main Series

1.  NA Series (Solid-ring needle roller bearings)

Comprising an inner ring, an outer ring and a needle roller assembly, these bearings feature a separable design, offer stable precision and can be fitted to shafts individually. Common types: NA4900, NA4902, NA4904, NA6900.

2.  NK Series (Inner-ring-less Needle Roller Bearings)

These do not have an inner ring; instead, the hardened shaft surface serves as the raceway, further reducing the radial space required. Common types: NK20/16, NK25/20.

3.  HK Stamped Outer Ring Needle Roller Bearings (Perforated Type)

Featuring a stamped outer ring made from thin sheet steel, these bearings are compact in size and are pressed into the housing bore for installation; they offer low unit costs in bulk production. Common types: HK0810, HK1012, HK1216.

4.  BK Stamped Outer Ring Needle Roller Bearings (Sealed Type)

Closed at one end, these provide simple protection against oil and dust; they cannot be installed with the shaft end open.

5.  RNA Series

Solid-ring needle roller bearings without an inner ring; they differ from the NK series in that they feature a solid, thick outer ring, offering higher load-carrying capacity than the stamped versions.

6.  AXK Needle Thrust Bearings

Designed to withstand axial loads, consisting of a needle roller cage and two washers.

Performance Characteristics

- Small radial cross-section, high radial load-carrying capacity, moderate limiting speed

- For versions without an inner ring, the shaft surface must be hardened and ground; they must not be used if the required hardness is not achieved

- Withstands virtually no axial forces

- Versions with stamped outer rings are pressed directly into the housing bore and do not require additional axial positioning

Applications

Gearboxes, motorcycles, engines, oil pumps, construction machinery, clutches, textile machinery and various compact transmission mechanisms.