Because the linear contact between rolling elements and raceway, these cylindrical roller bearings are featured by higher radial load capacity and are suitable for high speed applications.
Depending on the existence or absence of side ribs (flanges), cylindrical roller bearings are classified into NU, NJ, NUP, N, NF types of single row cylindrical roller bearings, and NNU, NN types of double row cylindrical roller bearings. The inner and outer rings of all types adopt separable design. The cylindrical roller bearings are generally fitted with pressed steel sheet cages or machined brass cages, and sometimes molded polyamide cages are also used.
Cylindrical roller bearings are widely applicable to large and medium-size motors, locomotives, machine tool spindles, internal combustion engines, generators, gas turbine engines, gearboxes, rolling mills, vibrating screen, lifting and material handling equipment, etc.
N Type Cylindrical Roller Bearing: has two integral flanges on inner ring and no integral flange on outer ring, axial displacement of the shaft relative to the housing is permitted in both directions.
NU Type Cylindrical Roller Bearing: has two integral flanges on outer ring and no integral flange on inner ring, axial displacement of the shaft relative to the housing is permitted in both directions.
Therefore, these cylindrical roller bearings are used as free-end bearings.
NJ Type Cylindrical Roller Bearing: has two internal flanges on outer ring and one integral flange on inner ring, enabling the bearing to handle axial load in one direction.
NF Type Cylindrical Roller Bearing: has two internal flanges on inner ring and one integral flange on outer ring, enabling the bearing to handle axial load in one direction.
Therefore, these cylindrical roller bearings are used as locating bearings guiding the shaft axially in single direction.
NUP Type Cylindrical Roller Bearing: has two internal flanges on outer ring, one integral flange and one loose flange on inner ring, enabling the bearing to handle axial load in both directions.
NFP Type Cylindrical Roller Bearing: has two internal flanges on inner ring, one integral flange and one loose flange on outer ring, enabling the bearing to handle axial load in both directions.
These bearings can limit axial displacement of the shaft relative to the housing in both directions. Therefore, they are used as locating bearings guiding the shaft axially in both directions.
NH (NJ+HJ) Type Cylindrical Roller Bearing: consist of NJ type cylindrical roller bearing and HJ type L-shaped thrust collar.
NH type cylindrical roller bearings can limit axial displacement of the shaft relative to the housing in both directions. Therefore, they can be used as fixed-end bearings.
Double row cylindrical roller bearings are available in cylindrical bore and tapered bore (designation suffix K). These bearings are featured by compact structure, high rigidity and high load carrying capacity, and particularly well suited for machine tool spindles. Typically, tapered bore allows for adjusting the internal clearance of the bearing, greatly simplifying shaft mounting and dismounting.
NN Type Cylindrical Roller Bearing: has three integral flanges on inner ring and no integral flange on outer ring, axial displacement of the shaft relative to the housing is permitted in both directions.
NNU Type Cylindrical Roller Bearing: has three integral flanges on outer ring and no integral flange on inner ring, axial displacement of the shaft relative to the housing is permitted in both directions.
Therefore, these cylindrical roller bearings are used as free-end bearings, and machined solid cages are most commonly used.
NNF Type Double Row Full Complement Cylindrical Roller Bearing: has one outer ring with middle flange and two inner rings with two flanges. Two inner rings are kept together by retaining rings. This arrangement allows the bearings to carry large radial and axial loads, often used as a fixed-end bearing.
NNF type bearings have contact seals on both sides. They are filled with grease, the operating temperature for the grease ranges from -50°C to +110°C. However, the operating temperature for the bearings is within a range of -40°C - +80°C due to the limitation of sealing material. Under certain conditions, especially when operated at medium or high speed, or exposed to water vapor and polluted environment for a long time, etc., the NNF type bearings have to be relubricated through the oil grooves and oil holes on the outer ring.
| Bearing series | ID(mm) | OD(mm) | Width(mm) | Processing range |
|---|---|---|---|---|
| NU406 | 30 | 90 | 23 | 30-300mm |
| NU1007 | 35 | 62 | 14 | |
| NU207E | 35 | 72 | 17 | |
| NU408 | 40 | 110 | 27 | |
| NU412 | 60 | 150 | 35 |
