Technology

BALL BEARING-TOLERANCE

Precision ball bearings are rated according to annular bearing engineers committee(ABEC) of the ABMA. Tolerances are the major differentiating factor between ABEC grades (e.g. ABEC-5 ball bearings have tighter tolerances than ABEC-1.  We also use ISO bearing tolerance which start PO. P6 . P5 then P4.


Note:The ABEC and ISO Bearing Standards are primarily concerned with bearing tolerance. It have not effect on radial play. although it is sometimes mistakenly thought that improving the tolerances will produce a bearing with less play. Assuming that the shaft and housing are manufactured to the same tolerances as the bearing, higher bearing tolerances will produce better mating between shaft/housing and bearing,


Comparison table is made as following for reference!

StandardClassification of tolerance
ANSIABEC1ABEC 3ABEC 5ABEC 7
SKF0P6P5P4
GB307-84GEDC
GB/T307-940654
ISO0654
JISP0P6P5P4
DINP0P6P5P4



ROLLING BEARINGS-CHAMFER DIMENSION-MAXIMAL VALUES
 SUMMARIZE FROM ROLLING BEARINGSCHAMFER DIMENSIONMAXIMAL VALUES OF GB/T274-2000, IDT ISO 5821995, ROLLING BEARINGSCHAMFER DIMENSIONMAXIMAL VALUES
RSMIN(MM)D(MM)RSMAX(MM)RAMAX(MM)
UP     TORADIALAXIAL
0.05-       -0.10.20.05
0.08-       -0.160.30.08
0.1-       -0.20.40.1
0.15-       -0.30.60.15
0.2-       -0.50.80.2
0.3-       400.610.3
40       -0.81
0.6-       40120.6
40       -1.32
1-       501.531
50       -1.93
RSMIN THE LARGEST SINGLE CHAMFER DIMENSION OF SHAFT AND BORE.
IF THE BREADTH OF BEARINGS IS 2MM, THE VALUE OF RADIAL RSMIN IS THE SAME AS AXIAL ONE.


DIMENSIONS

d:Nominal Bore Diameter
D:Nominal Outside Diameter
D1:Outer ring flange outside diameter, basic
B:Nominal Inner Ring Width
C:Nominal Outer Ring Width
 r:Chamfer Dimension of Inner Ring or Outer Ring


DIMENSIONAL DIFFERENCES

Δds:Dimensional difference of bore diameter
Δdmp:Dimensional difference of mean bore diameter in the plane
(Δdm):Dimensional difference of mean bore diameter
ΔDs:Dimensional difference of outside diameter
ΔDmp:Dimensional difference of mean outside diameter in the plane
(ΔDm):Dimensional difference of mean outside diameter
ΔBs:Dimensional difference of inner ring width
ΔCs:Dimensional difference of outer ring width
ΔD1s:Deviation of a single flange outside diameter
ΔC1s:Deviation of a single width of the outer ring flange


LIMIT VALUES OF CHAMFER/RADIUS DIMENSION

rs:Chamfer dimension of inner ring or outer ring
rs min:Minimum dimension limit of inner ring and outer ring chamfer
rs max:Maximum dimension limit of inner ring and outer ring chamfer


INEQUALITY OF DIMENSIONS

VBs:Inequality of inner ring width
VCs:Inequality of outer ring width
VC1s:Inequality of flanged width


ROTATION PRECISION

Kia (Ki):Radial runout of inner ring
Sia (Si):Axial runout of inner ring
Sd (Sdi):Side runout of inner ring
[runout of inner ring reference face with respect to the bore]
Kea (Ke):Radial runout of outer ring
Sea (Se):Axial runout of outer ring
SD (SD):Side runout of outer ring
[variation of outside surface generatrix inclination with respect to the outer ring reference face]
SD1:[variation of outside surface generatrix inclination with respect to the outer ring flange back face]
Seal:Axial runout of outer ring flange back face