Cylindrcal rolller bearing belone to separate bearings, inner and outer ring roller are line contact,friction coefficient is low, speed rate is higt, it just bear radical load,and little axis load. Double row cylindrical roller bearing andtree row、four row cylindrical roller bearing possess structure compaction、strength rigidity、little derivative after stress. It is extensively to be used in lather,petro drilling equipment,large heave rolling mining and so on.