Product tolerance and precision selection of motor bearings

Tolerance product tolerance and accuracy Select ZWZ motor bearing product accuracy with 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, and the tolerances are shown in the table below. . The accuracy increases sequentially from level 0. For general purposes, level 0 is sufficient, but in special conditions or occasions, higher precision is required. Dimensional accuracy (items related to shaft and housing installation) Permissible deviation of inner diameter, outer diameter and width Permissible limit value of chamfering dimension Permissible variation in width Permissible deviation and permissible variation in taper hole Rotation accuracy (related to the runout of the rotating body Item) Allowable radial runout and axial runout of the inner ring and outer ring Allowable lateral runout of the inner ring Allowable variation tolerance symbol of the inclination of the outer diameter surface External dimension symbol (Figure 1). d: Nominal inner diameter of the bearing d1: The basic diameter of the basic tapered hole at the theoretical big end △ds: The diameter deviation of a single inner hole △dmp: The average inner diameter deviation of a single plane (for tapered holes △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 big end Vdp: The variation of the inner diameter of a single radial plane Vdmp: The variation of the average inner diameter (only for cylindrical holes): Nominal half taper angle D: Nominal bearing outer diameter D1: Nominal outer ring flange Outer diameter △Ds: Single outer diameter deviation △Dmp: Single plane average outer diameter deviation Nominal 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 : Variation in outer ring width VC1s: Variation in outer ring flange width Kia: Radial runout of the inner ring of the bearing set Kea: Radial runout of the outer ring of the bearing set Sd: Runout SD of the reference end face (back surface) of the inner ring to the inner hole : Variation in the inclination of the bus bar on the outer diameter surface to the reference end face (back) SD1: Variation in the inclination of the bus bar on the outer diameter surface against the back of the flange Sia: Runout of the inner ring end face (back) of the bearing set against the raceway Sea: Bearing set Runout of the outer ring end face (back) to the raceway Sea1: Runout of the back of the flange of the complete set of bearings to the raceway Fig. 1 External dimension symbol B table 10 Class 0 tolerance inner ring C Tolerance value of radial bearings (except tapered roller bearings) Class 0 tolerance (Table 10, Table 11) 3.2 The selection of product accuracy is based on the calculation of the bearing limit speed to determine the use accuracy of the bearing. If the limit speed is not enough, the accuracy level needs to be increased. Depending on the fit and the remaining internal clearance, the accuracy level needs to be improved.