The rolling elements are radial rolling bearings with cylindrical rollers. The internal structure of cylindrical roller bearings adopts rollers arranged in parallel, and spacers or spacers are installed between the rollers, which can prevent the rollers from tilting or rubbing against each other, and effectively prevent the increase of rotational torque.

The outer ring of the N-type bearing has no ribs, and there are ribs on both sides of the inner ring. It can allow the displacement of the shaft in two directions in the axial direction relative to the bearing seat. NU type bearings have ribs on both sides of the outer ring and no ribs on the inner ring. It is also possible to allow the displacement of the shaft in two directions in the axial direction relative to the bearing seat. Therefore, this type of structure is suitable for use as a floating end bearing.

NJ, NF type

NJ type bearings have ribs on both sides of the outer ring and ribs on one side of the inner ring. Can withstand a certain amount of unidirectional axial load. The NF type has ribs on one side of the outer ring and ribs on both sides of the inner ring. It can also bear a certain amount of unidirectional axial load. Therefore, this type of structure is suitable for use as a one-way axial positioning bearing.

NUP, NFP type

The NUP type bearing has ribs on both sides of the outer ring, a (fixed) single rib on one side of the inner ring, and a detachable flat ring on the other side. Can withstand a certain amount of bidirectional axial load.

The NFP bearing outer ring has a (fixed) single rib on one side, and a separable flat rib on the other side, and ribs on both sides of the inner ring. It can also withstand a certain amount of bidirectional axial load. This type of structural bearing can limit the displacement of the shaft relative to the bearing housing in both axial directions. Therefore, it is suitable for use as a fixed end bearing.

NH (NJ+HJ) type

NH type bearing is a combination of NJ type bearing and HJ type oblique retaining ring. Since the inner ring of the NUP bearing is short and the flat retaining ring is not fixed, it is inconvenient to use, while the NH bearing can use the width of the entire inner ring of the NJ bearing to maintain a tighter fit with the shaft. Moreover, NH type bearings are more convenient to install and disassemble.
NH type bearings can limit the displacement of the shaft relative to the bearing housing in both axial directions. Therefore, it is suitable for use as a fixed end bearing.

Double Row Bearing

Double-row cylindrical roller bearings have two structures: cylindrical inner hole and conical inner hole (bearing code plus K). This type of bearing has the advantages of compact structure, high rigidity, large bearing capacity, and small deformation after being loaded, and is especially suitable for supporting the spindle of machine tools. The conical inner hole can also play the role of micro-adjusting the clearance, and can simplify the structure of the positioning device, which is convenient for installation and disassembly.

Commonly used double row cylindrical roller bearings have the following forms:

NN, NNU type
The outer ring of the NN type bearing has no ribs, and the inner ring has ribs on both sides and a middle rib in the middle. It can allow the displacement of the shaft in two directions in the axial direction relative to the bearing seat.
NNU type bearings have ribs on both sides of the outer ring and middle ribs in the middle, and no ribs on the inner ring. It can allow the displacement of the shaft in two directions in the axial direction relative to the bearing seat. Therefore, this type of structure is suitable for floating end bearings. The cage of this type of bearing mostly adopts a car-made solid cage.

NNF type
NNF type bearings are double-row full complement cylindrical roller bearings. The bearings consist of an outer ring with a middle rib and two inner rings with double ribs. The rollers are guided by the ribs of the inner rings, and the two inner rings are held together with a fastening ring. In addition to bearing large radial loads and axial loads, this structure can also withstand overturning moments, so it is often used as a fixed end bearing.
Both sides of the NNF type bearing adopt contact seal. The bearing is filled with grease, and the working temperature of the grease is -50°C to +110°C, but due to the limitation of the sealing material, the working temperature of the bearing is limited to -40°C to +80°C. In the case of good working conditions, the sealed NNF bearing does not need to be maintained. If the bearing is in the water vapor or polluted environment for a long time, and it is running at a medium or high speed, it can be lubricated through the lubricating oil groove and lubricating oil hole on the outer ring. The bearings are relubricated.

Four Row Bearing