Tolerance-Tapered Roller Bearings

The tolerance of LYC standard bearings conforms to Chinese national standards:

GB/T307.1

GB/T273.2

The tolerance of special bearings such as rolling mill bearings, machine tool spindle bearings and inch size bearings, execute their related stipulations separately.

The dimension and rotating accuracy of rolling bearing have been internationalized (Table 8.1). According to the stipulations in national standard, the dimension and rotating accuracy of metric bearings are divided into five tolerance classes, class 0, class 6, class 5, class 4, class 2, and the precision classes are increasing in sequence.

Table 8.1

Tolerance Symbols:

d Bearing bore diameter, nominal

Δds Deviation of a single bore diameter

Δdmp Single plane mean bore diameter deviation (for a tapered bore, refers only to the theoretical small end of bore)

Vdp Bore diameter variation in a single radial plane

Vdmp Mean bore diameter variation (only applies to a cylindrical bore)

D Bearing outer diameter, nominal

D1 Outer ring flange outer diameter, nominal

ΔDs Deviation of a single outer diameter

ΔD1s Deviation of outer flange of a single outer ring

ΔDmp Single plane mean outer diameter deviation

VDp Outer diameter variation in a single radial plane

VDmp Mean outer diameter variation

B Inner ring width, nominal shaft washer

ΔBs Deviation of a single width of the inner ring

VBs Inner ring width variation

C Outer ring width, nominal

C1 Outer flange width, nominal

Δcs Deviation of a single width of the outer ring

Vcs Outer ring width variation

Kia Radial runout of assembled bearing inner ring

Kea Radial runout of assembled bearing outer ring

Sd Verticality of end face of inner ring towards bore

SD Verticality of outer surface of outer ring towards end face

SD1 Verticality of outer surface of outer ring towards flange backface

Sia Axial runout of assembled bearing inner ring

Sea Axial runout of assembled bearing outer ring

Sea1 Axial runout of assembled bearing flange backface

Added Tolerance Symbols of Taper Roller Bearing

T Bearing width, nominal

T1 Bearing nominal width composed by sub-unit and standard outer ring

T2 Bearing nominal width composed by outer ring and standard sub-unit

ΔTs Deviation of the actual bearing width

ΔT1s Actual deviation of T1

ΔT2s Actual deviation of T2