Because the bearings are standard parts, the bearing inner ring aperture and the outer ring shaft diameter tolerance zone has been determined at the time of manufacture, bearing journal and shell holes with the decision by the journal and the tolerance of the housing bore with. Was chosen bearing with is to determine the type of tolerance zone of the journal and the shell holes, the journal under the national standard GB / T 275-1993 and shell hole tolerance zone. The tolerance zone applies only in the following situations: ① bearing Dimensions comply with GB / T 273.3-1999 "provisions of the bearing to the heart bearing Dimensions program"; ② bearing accuracy class 0 and 6 (6x) level; ③ bearings the clearance for the basic set of radial clearance; ④ shaft is solid or thick-walled steel shaft; the ⑤ housing of cast steel or cast iron.
Here hole tolerance zone below the zero line, while the GB / T 1801-1999 the cylindrical tolerance standard reference hole tolerance zone above the zero line, so the tie, as its datum (inner diameter, outer bearing circle OD) tolerance zone relative relationship with the size of the journal or shell hole deviation. Apparently bearing inner ring and the journal with GB / T 1801-1999 hole basis the same name with the tight. On the bearing inner ring and the shaft with the many gaps of the cylindrical standard tolerance fit here actually become a transition fit, such as commonly used fitting, G5, G6, H5, H6 with the transition complex has become; while transition fit here actually has become an interference fit, such as commonly used with the k5, k6 m5, m6 cooperation has become an interference fit the remaining tie has become tight. Bearing outer ring with shell holes with GB / T 1801-1999 cylindrical tolerance standard specifies basic shaft system similar with the comparison, although the size of the tolerance value is different, but with the consistent nature. Just bearing outer diameter smaller values of tolerance, and thus with little tight, H6, H7, H8 has become a transition fit.
Product Model | Inside Diameter | Outside Diameter | Thickness |
7211CTYNP5 NSK | 55 | 100 | 21 |
7210ATYNP5 NSK | 50 | 90 | 20 |