Needle Roller Bearings Without an Inner Ring (also commonly known as a needle roller and cage assembly) are a type of roller bearing that utilizes thin, cylindrical rollers retained by a cage. The defining characteristic of this design is the absence of a dedicated inner ring. Instead, the hardened and ground surface of the shaft itself acts as the inner raceway for the needle rollers. This design achieves the most compact possible radial cross-section, allowing for a significant reduction in size and weight of the surrounding assembly. It is the optimal choice when the highest possible load capacity is required within a minimal radial space, provided that the mounting shaft can be appropriately hardened and ground.
| Anfrage | Bearing Number | Principal dimensions （mm) | Weight(Kg) | ||
|---|---|---|---|---|---|
| d | D | B | |||
| HK 1010 | 10 | 19 | 10 | 10 | |
| HK 1212 | 12 | 21 | 12 | 15 | |
| HK 1515 | 15 | 24 | 15 | 20 | |
| HK 1717 | 17 | 26 | 17 | 25 | |
| HK 2020 | 20 | 30 | 20 | 35 | |
| HK 2525 | 25 | 37 | 25 | 50 | |
| HK 3030 | 30 | 42 | 30 | 70 | |
| HK 3535 | 35 | 47 | 35 | 90 | |
| HK 4040 | 40 | 52 | 40 | 110 | |
| HK 5050 | 50 | 62 | 50 | 150 | |
| NK 10 | 10 | 28 | 10 | 12 | |
| NK 12 | 12 | 32 | 10 | 15 | |
| NK 15 | 15 | 35 | 12 | 20 | |
| NK 20 | 20 | 42 | 12 | 25 | |
| NK 25 | 25 | 47 | 12 | 30 | |
