The composition of the bearing model of the precision double row cylindrical roller bearing, the example model: NN3006W33M2KC1NAP4. Collected by Qingdao Ruijing Electromechanical Equipment Co., Ltd. for you. NNu003dBearing type code NN: Double-row cylindrical roller bearing (with ribs on the inner ring and no ribs on the outer ring) NNU: Double-row cylindrical roller bearing (with no ribs on the inner ring, and ribs on the outer ring) 30u003dSize Series code 49: 49 series 30: 30 series 06u003dinner diameter code (inner diameter size)u003d(inner diameter code)×5 mm W33u003doil hole code (not marked): outer ring with oil tank, no oil hole W33: outer ring with Oil tank with oil hole M2u003dCage code (not marked): Brass car-made cage (integrated type) M2: Brass car-made cage (separate type) Ku003dInner diameter shape code (not marked): Cylindrical hole Inner diameter K: Inner diameter of tapered hole C1NAu003dInternal clearance code C9NA: Non-interchangeable clearance (inner diameter of tapered hole) C1NA: Non-interchangeable clearance (inner diameter of cylindrical hole and tapered hole) C2NA: Non-interchangeable clearance ( Cylindrical hole and tapered hole inner diameter) CNA: Non-interchangeable clearance (cylindrical hole inner diameter) C3NA: Non-interchangeable clearance (cylindrical hole inner diameter) P4u003dAccuracy grade code P5: JIS level 5 P4: JIS level 4 Due to the relatively simple structure, high precision is achieved. In addition, as the number of steel balls increases, the rigidity of the bearing is improved. ● Compared with tapered roller bearings, the light sliding part is reduced, so there is less heat generation. ● When installing the tapered bore bearing, the clamping amount of the inner ring can be adjusted, and the radial internal clearance can be adjusted. ● Since it cannot bear axial load, it is usually used in combination with thrust bearing. The cages NN3000 series and NNU4900 series are all based on the roller guide cage made of brass alloy as the standard. Dimensional accuracy and rotation accuracy ● compliant with JIS grade 5 or JIS grade 4. Please refer to page 7. ● The dimensional accuracy of the inner diameter tapered hole is a unique allowable value. Please refer to page 11. Radial internal clearance In order to control the deviation of shaft vibration, non-interchangeable clearances are independently set for cylindrical holes and tapered holes.