The structure of NACHI precision double row cylindrical roller bearing bearing model, 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, no ribs on the outer ring) NNU: Double row cylindrical roller bearing (without ribs on the inner ring, with ribs on the outer ring) 30u003dDimensions Series code 49 : 49 series 30 : 30 series 06 u003d ID code (inner diameter size) u003d (inner diameter code) 5 mm W33 u003d oil hole code (not marked) : outer ring with oil drain, no oil hole W33 : outer ring with oil Cao, with oil hole M2u003dCage code (not marked) : Brass machined cage (integrated type) M2 : Brass machined 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 (inner diameter of cylindrical hole) Conical hole inner diameter) CNA : Non-interchangeable clearance (cylindrical hole inner diameter) C3NA : Non-interchangeable clearance (cylindrical hole inner diameter) P4 u003d Accuracy class code P5 : JIS class 5 P4 : JIS class 4 Features Due to structural comparison Simple, high precision is achieved. In addition, with the increase of the number of steel balls, the rigidity of the bearing is improved. ● Compared with NACHI tapered roller bearings, the smooth sliding part is reduced, so the heat generation is relatively small. ● When installing tapered bore bearings, the clamping amount of the inner ring can be adjusted, and the radial internal clearance can be adjusted. ● Because it cannot bear axial load, it is usually used in combination with thrust bearing. The cages NN3000 series and NNU4900 series are roller-guided cages made of brass alloy as standard. Dimensional Accuracy Rotational Accuracy ● Based on JIS Class 5 or JIS Class 4. Please refer to page 7. ● The dimensional accuracy of the inner diameter tapered hole is the allowable value of NACHI alone. Please refer to page 11. Radial Internal Clearance In order to control the deviation of shaft vibration, NACHI independently sets non-interchangeable clearances for cylindrical bores and tapered bores. Please refer to page 21. Outer ring oil hole size The outer ring oil hole oil tank size (W33 specification) can refer to the following data.