Cylindrical roller bearings belong to the separate type bearings,whose  roller and raceway is linear contact and whose  radial load  capacity is greater applying to heavy load and shock load and high speed conditions.the mounting and dismounting of such bearings is more convenient,when the requirements of inner and outer ring interference fit ,its advantages are demonstrated .this bearing can be classified  into single-row ,double-row ,four-row cylindrical roller bearings according to the rows of rollers. In addition ,there are Cylindrical roller bearings with a full complement of  rollers and other arrangements,one of which is the most widely used --single row cylindrical roller bearings with cage.
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Four-row cylindrical roller bearings has the advantages of larger radial carrying capacity,high precision of rotating,convenience of mounting  and dismounting ,but it can not withstand axial load.because of  the inner ring without ribs ,inner and outer ring components can be installed( with full sets of rollers and cages). This bearings can be classified  into FC type ,FCD type and FCDP type,mainly used in the heavy machinery (hot and cold roller mill,bloomers  and other heavy machineries  )as working  roll and backup roll .
cylindrical roller bearings with  Full complement of rollers have two types: single-row (NCF) and double-row (NNCF) full complement of roller cylindrical roller bearings because such bearings have no cage and have larger number of rollers, their carrying capacity is large,but the high speed performance is poor,generally used in low speed and heavy load application.
The cage of cylindrical roller bearings ,when its outer diameter D<=400mm,generally use pressed
steel plate (or belt) cage,when D>400mm ,use steel or brass machined solid cage;four-row cylindrical roller bearings use brass cage or pin column cage.

FOUR ROW CYLINDRIACAL ROLLER BEARING d150-180mm