Bearings, units and housings -- Super-precision bearings -- Angular contact ball bearings -- Angular contact ball bearings, super-precision -- SKF 71908 ACD/P4A
71908 ACD/P4A
Dimensions
| d | 40 | mm | |
| D | 62 | mm | |
| B | 12 | mm | |
| d1 | 47.1 | mm | |
| d2 | 47.1 | mm | |
| D1 | 54.9 | mm | |
| r1,2 | min. | 0.6 | mm |
| r3,4 | min. | 0.3 | mm |
| a | 18 | mm |
Abutment dimensions
| da | min. | 43.2 | mm |
| db | min. | 43.2 | mm |
| Da | max. | 58.8 | mm |
| Db | max. | 60.6 | mm |
| ra | max. | 0.6 | mm |
| rb | max. | 0.3 | mm |
| dn | 48.7 | mm |
Calculation data
| Basic dynamic load rating | C | 11.7 | kN | |
| Basic static load rating | C0 | 8 | kN | |
| Fatigue load limit | Pu | 0.34 | kN | |
| Attainable speed for grease lubrication | 18000 | r/min | ||
| Attainable speed for oil-air lubrication | 30000 | r/min | ||
| Ball diameter | Dw | 6.35 | mm | |
| Number of balls | z | 21 | ||
| Reference grease quantity | Gref | 1.44 | cm³ | |
| Preload and stiffness (back-to-back, face-to-face) | ||||
| Preload class A | GA | 70 | N | |
| Static axial stiffness, preload class A | 89 | N/µm | ||
| Preload class B | GB | 140 | N | |
| Static axial stiffness, preload class B | 115 | N/µm | ||
| Preload class C | GC | 280 | N | |
| Static axial stiffness, preload class C | 151 | N/µm | ||
| Preload class D | GD | 560 | N | |
| Static axial stiffness, preload class D | 199 | N/µm | ||
| Calculation factors | ||||
| Calculation factor | f | 1.09 | ||
| Calculation factor | f1 | 0.98 | ||
| Calculation factor | f2A | 1 | ||
| Calculation factor | f2B | 1.04 | ||
| Calculation factor | f2C | 1.08 | ||
| Calculation factor | f2D | 1.14 | ||
| Calculation factor | fHC | 1 | ||
| Calculation factor | e | 0.68 | ||
| Calculation factor (single, tandem) | Y2 | 0.87 | ||
| Calculation factor (single, tandem) | Y0 | 0.38 | ||
| Calculation factor (single, tandem) | X2 | 0.41 | ||
| Calculation factor (back-to-back, face-to-face) | Y1 | 0.92 | ||
| Calculation factor (back-to-back, face-to-face) | Y2 | 1.41 | ||
| Calculation factor (back-to-back, face-to-face) | Y0 | 0.76 | ||
| Calculation factor (back-to-back, face-to-face) | X2 | 0.67 | ||
Mass
| Mass bearing | 0.11 | kg |