Cylindrical roller bearings

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  Single-row cylindrical roller bearings
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  Double row cylindrical roller bearing
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  Four-row cylindrical roller bearings
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  Single-row full complement cylindrical roller bearings
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  Double-row full complement cylindrical roller bearings

Ⅰ. Cylindrical roller bearing
Cylindrical roller bearings are separable bearings, easy to install and disassemble. It is divided into single row, double row, four row and full complement roller bearings based on the number of rollers installed. Cylindrical roller bearings have the high radial load capacity and are suitable for high acceleration and high speed operation.
(1) Single row cylindrical roller bearing
Single row cylindrical roller bearings are separable bearings. The rolling element is guided by two flanges of the bearing ring. Single row cylindrical roller bearings generally consist of four components: inner ring, outer ring, rolling element and cage. Such bearing is easy to install, disassemble, and suitable for high speed operation. Therefore, compared with annular ball bearing of the same size, it is more suitable for larger radial load and has better impact resistance, but it is not generally used to withstand axial load. The axis inclination of the inner and outer rings of such bearing should be very small, generally ≤ 4′. After the rolling element and raceway generatrix are modified, the requirement for inclination can be reduced appropriately. For details, please consult E-FINE engineer.
The common structures are following four types :
N design
♦ This type of bearing, having inner ring with double flanges and outer ring without flange, is generally used as the non-positioning bearing.
NU design
♦ This type of bearing, having outer ring with double flanges and inner ring without flange, is generally used as the non-positioning bearing.
NJ design
♦ This type of bearing, having outer ring with double flanges and inner ring with a flange, has a certain of unidirectional axial load capacity.
NF design
♦ This type of bearing, having inner ring with double flanges and outer ring with a flange, can be used as the positioning bearing and has a certain of unidirectional axial load capacity.
(2) Double row cylindrical roller bearing
Double row cylindrical roller bearings are separable bearings, easy to install and disassemble.
Double row cylindrical roller bearings have two types of structure: cylindrical and tapered bores (post code K). There are two main types: NNU design and NN design. The NN design has inner ring with two flanges and outer ring without flange, and the NNU design has inner ring without flange and outer ring with double flanges. Tapered bore structure can adjust radial clearance during installation. A certain of axial displacement between the bearing and the bearing housing is allowed in the double row cylindrical roller bearing, which can be used as the non-positioning bearing.
With good rigidity and high accuracy, double row cylindrical roller bearings are usually suitable for spindle bearings of precision machine tools.
(3) Four row cylindrical roller bearing
Four row cylindrical roller bearings are mainly used on metallurgical equipment as main roll bearings. Because of its compact structure, good rigidity and high bearing capacity, it is the most widely used rolling mill bearings. This type of bearing is unable to bear axial load. Therefore, it is necessary to use together with thrust bearing to withstand axial load.
Four row cylindrical roller bearings are separable bearings. Because its inner ring has no flange, the inner ring and outer ring components can be installed and disassembled separately, which is beneficial to the installation and maintenance of bearings.
It is mainly applicable to rolling mill with high rotational speed and precision. For example, wire mill, section mill, cold or hot plate mill, breakdown mill, etc. Brass solid cage or pillar welding cage is generally used.
(4) Full complement cylindrical roller bearing
Because the ring raceways are full of rollers and having no cage, the full complement cylindrical roller bearings have higher bearing capacity. At the same time, because this type of bearing has no cage to guide and separate the roller, there will be relative slippage between the rollers. So, compared with the ordinary cylindrical roller bearings, their using speed is lower and noise is lager. The main structures are: single row (NCF type) and double row (NNCF) bearings.
NCF type
♦NCF - it is single row roller bearing, can carry unidirectional axial load, and can be used as unidirectional positioning bearing;
NNCF type
♦ NNCF - it is double row roller bearing, can carry unidirectional axial load, can be used as unidirectional positioning bearing, and is suitable for the low speed and heavy load conditions.
♦ Closed double row full complement cylindrical roller bearings are mainly used for wire rope pulley of crane.