Solid-ring needle roller bearings

Solid Ring Needle Roller Bearings with Flanges

Solid ring needle roller bearings with flanges consist of one or two rings and a needle roller set with a cage. These bearings feature a compact size and high load-carrying capacity. Therefore, they can meet the requirements of lightweight design, limited installation space, and high power transmission. Depending on the application, bearings may be used with or without an inner ring.

Main Structural Types

Outer Ring Double-Flanged (or Double Snap Ring) Needle Roller Bearings with Cage – Types NA, NKI

These bearings allow separate installation of inner and outer rings (with snap rings, full complement of needle rollers, and cage). They offer high limiting speed and are available in single-row and double-row types.

If the shaft cannot be used as a raceway—i.e., if hardening and grinding the shaft is not possible or is uneconomical—this type of bearing with an inner ring can be used.

Needle Roller Bearings with Cage without Inner Ring

When NA and NKI type bearings are used without an inner ring, they become RNA and NK type needle roller bearings.

These bearings have no inner ring and are suitable for support structures with limited radial installation space. The shaft journal directly serves as the rolling surface. The shaft used as the raceway must be hardened and ground, and only when it achieves appropriate dimensional and geometric accuracy can the full set of needle rollers achieve high service life and running accuracy. At the same time, since there is no inner ring, the shaft diameter can be appropriately increased, thereby improving rigidity.

Sealed Needle Roller Bearings with or without Inner Ring

Single-sided or double-sided sealed needle roller bearings effectively prevent the intrusion of contaminants. These bearings are pre-filled with an appropriate amount of lithium-based grease. The inner ring is wider than the outer ring, allowing the bearing to maintain good sealing performance even when there is slight axial displacement between the shaft and housing, preventing contamination. The inner ring is also equipped with lubrication holes, allowing supplementary lubrication from either the outer ring or inner ring depending on the configuration requirements.