Tolerance product tolerance and accuracy selection ZWZ motor bearing product accuracy has P0, P6, P5, P4, P2 grades. For users with special requirements, products with stricter precision can also be processed. The tolerances are in line with GB307.1. The tolerances are shown in the table below. . The accuracy is increased sequentially from level 0, which is sufficient for general purpose level 0, but in special conditions or occasions, higher accuracy is required. Dimensional accuracy (items related to shaft and housing installation) allowable deviation of inner diameter, outer diameter, and width allowable limit value of chamfer size allowable variation of width allowable variation of conical hole and allowable variation of rotation accuracy (related to the beating of the rotating body Item) Permissible radial runout and axial runout of the inner ring and outer ring Permissible lateral runout of the inner ring Permissible variation of the tolerance symbol of the outer diameter surface inclination (Figure 1). d: the nominal inner diameter of the bearing d1: the basic diameter of the basic cone hole at the theoretical large end △ds: the diameter deviation of a single inner hole △dmp: the average inner diameter deviation of a single plane (for a tapered hole △dmp only refers to the theoretical small end of the inner hole) △d1mp: The average inner diameter deviation of the basic tapered hole at the theoretical large end Vdp: the variation of the inner diameter of a single radial plane Vdmp: the average variation of the inner diameter (only for cylindrical holes) α: the nominal half cone angle D: the nominal outer diameter of the bearing D1: outer ring flange Nominal outer diameter △Ds: single outer diameter deviation △Dmp: single plane average outer diameter deviation △D1s: outer ring flange single outer diameter deviation VDp: single radial plane outer diameter variation VDmp: average outer diameter variation B: inner Nominal ring width △Bs: inner ring single width deviation VBs: inner ring width variation C: outer ring nominal width C1: outer ring flange nominal width △Cs: outer ring single width deviation △C1s: outer ring flange single width deviation VCs: Outer ring width variation VC1s: Outer ring flange width variation Kia: Radial runout of the inner ring of the set bearing Kea: Radial runout of the outer ring of the set bearing Sd: Runout of the inner ring reference end surface (back) to the inner hole SD: Variation in the inclination of the outer diameter surface bus bar to the reference end surface (back) SD1: Variation in the inclination of the outer diameter surface bus bar to the back of the flange Sia: Set bearing inner ring end surface (back) to raceway runout Sea: Set The run-out of the end face (back) of the outer ring of the bearing against the raceway Sea1: The run-out of the raceway on the back of the complete set of bearing flanges Figure 1 Outline dimension symbol B Table 10 0-level tolerance inner ring C Tolerance value Radial bearings (except for tapered roller bearings ) Class 0 tolerance (Table 10, Table 11) 3.2 Product accuracy selection is based on the calculation of the bearing limit speed to determine the accuracy of the bearing. If the limit speed is not enough, the accuracy level needs to be increased. The accuracy level needs to be improved according to the fit and remaining internal clearance.