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!
| Standard | Classification of tolerance | |||
| ANSI | ABEC1 | ABEC 3 | ABEC 5 | ABEC 7 |
| SKF | 0 | P6 | P5 | P4 |
| GB307-84 | G | E | D | C |
| GB/T307-94 | 0 | 6 | 5 | 4 |
| ISO | 0 | 6 | 5 | 4 |
| JIS | P0 | P6 | P5 | P4 |
| DIN | P0 | P6 | P5 | P4 |
| 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 TO | RADIAL | AXIAL | ||
| 0.05 | - - | 0.1 | 0.2 | 0.05 |
| 0.08 | - - | 0.16 | 0.3 | 0.08 |
| 0.1 | - - | 0.2 | 0.4 | 0.1 |
| 0.15 | - - | 0.3 | 0.6 | 0.15 |
| 0.2 | - - | 0.5 | 0.8 | 0.2 |
| 0.3 | - 40 | 0.6 | 1 | 0.3 |
| 40 - | 0.8 | 1 | ||
| 0.6 | - 40 | 1 | 2 | 0.6 |
| 40 - | 1.3 | 2 | ||
| 1 | - 50 | 1.5 | 3 | 1 |
| 50 - | 1.9 | 3 | ||
| 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 |
- > Structure Of Bearing
- > Bearing material
- > CAGE/RETAINER
- > SHIELD&SEAL DESIGN
- > BALL BEARING-TOLERANCE
- > VIBRATION AND NOISE
- > INTERNAL CLEARANCE
- > LUBRICATION
- > SHAFT/HOUSING FIT
- > BEARING DAMAGE
- > How to prolong the service time of bearings
- > The characteristics and causes of bearing grinding cracks and preventive measures
- > Item Interchange of miniature bearing