Cylindrical roller bearings

Cylindrical Roller Bearings

Cylindrical roller bearings typically consist of an assembly including two flanges on one bearing ring that guide the rollers, a cage, rollers, and a guide ring. In general, they are separable-type bearings. They are easy to install and disassemble, especially when both the inner and outer rings require an interference fit with the shaft and housing, where their advantages become more apparent.

This type of bearing generally has very high rigidity and is capable of carrying extremely high radial loads. Only single-row bearings with flanges on both inner and outer rings can carry small axial loads or large intermittent axial loads. Compared with deep groove ball bearings of the same size, cylindrical roller bearings offer higher radial load capacity and, from a structural standpoint, are also suitable for high-speed rotation.

The rollers and raceways of DFB cylindrical roller bearings adopt a crowned (modified) profile design, which eliminates edge stress and extends bearing life.

The flange design of DFB cylindrical roller bearings includes a certain inclination angle, allowing them to carry higher axial loads than conventional designs.

Cylindrical Roller Bearings with No Flanges on Inner or Outer Rings

NU-type cylindrical roller bearings have two flanges on the outer ring and no flanges on the inner ring.

N-type cylindrical roller bearings have two flanges on the inner ring and no flanges on the outer ring.

NU-type and N-type cylindrical roller bearings allow a certain degree of axial displacement between the shaft and housing in both directions. They can accommodate length changes caused by thermal expansion of the shaft, making them suitable as non-locating bearings. They can carry high radial loads but cannot withstand axial loads.

Cylindrical Roller Bearings with Flanges on Both Inner and Outer Rings

NJ-type cylindrical roller bearings have a double-flanged outer ring and a single-flanged inner ring.

NF-type cylindrical roller bearings have a single-flanged outer ring and a double-flanged inner ring.

NJ-type and NF-type cylindrical roller bearings can limit axial displacement in one direction of either the shaft or housing, achieving single-direction axial location while carrying small axial loads in one direction.

NUP-type cylindrical roller bearings have a double-flanged outer ring, a single flange on one side of the inner ring, and a loose flange ring on the other side. This type can provide bidirectional axial positioning of the shaft and withstand axial forces in both directions. The structural variant NUP...N is available. NJ-type bearings with an angled loose flange ring HJ can function similarly to NUP-type bearings and serve as locating bearings.

Cylindrical Roller Bearings without Inner or Outer Rings

RNU-type cylindrical roller bearings are bearings without an inner ring, with a double-flanged outer ring, essentially an NU-type cylindrical roller bearing without an inner ring.

RN-type cylindrical roller bearings are bearings without an outer ring, with a double-flanged inner ring.

RNU-type and RN-type cylindrical roller bearings are used in applications with limited radial space, where the shaft journal or housing bore surface directly serves as the raceway. The hardness, machining accuracy, and surface quality of the raceway must be comparable to that of a bearing ring raceway.

Full Complement Cylindrical Roller Bearings

These bearings typically use a structure with a double-flanged outer ring and a single-flanged inner ring, such as NJ...V, NUP...V, RNU...V, etc. The rolling elements are guided by the ring flanges. Due to the maximum number of rollers, compared with cage-type roller bearings of similar structure, they offer higher rated load capacity and simpler construction.

When operating speed and working temperature are not high, lubrication conditions are good, and housing cleanliness is relatively high, full complement structures are preferred.

Reinforced Cylindrical Roller Bearings

E-type cylindrical roller bearings have the same main dimensions as standard types, but with increased roller diameter, length, and quantity, resulting in higher load capacity.

These bearings are distinguished by the suffix “E” added to the basic model. Since their roller inscribed circle diameter differs from standard types, they are not interchangeable with standard cylindrical roller bearings.