Bearings, units and housings -- Super-precision bearings -- Angular contact ball bearings -- Angular contact ball bearings, super-precision -- SKF 71948 CD/P4A
71948 CD/P4A
Dimensions
| d | 240 | mm | |
| D | 320 | mm | |
| B | 38 | mm | |
| d1 | 264.7 | mm | |
| d2 | 264.7 | mm | |
| D1 | 295.3 | mm | |
| r1,2 | min. | 2.1 | mm |
| r3,4 | min. | 1 | mm |
| a | 56.6 | mm |
Abutment dimensions
| da | min. | 251 | mm |
| db | min. | 251 | mm |
| Da | max. | 309 | mm |
| Db | max. | 315 | mm |
| ra | max. | 2 | mm |
| rb | max. | 1 | mm |
| dn | 271.4 | mm |
Calculation data
| Basic dynamic load rating | C | 229 | kN | |
| Basic static load rating | C0 | 325 | kN | |
| Fatigue load limit | Pu | 8.15 | kN | |
| Attainable speed for grease lubrication | 3800 | r/min | ||
| Attainable speed for oil-air lubrication | 5600 | r/min | ||
| Ball diameter | Dw | 25.4 | mm | |
| Number of balls | z | 31 | ||
| Reference grease quantity | Gref | 93 | cm³ | |
| Preload and stiffness (back-to-back, face-to-face) | ||||
| Preload class A | GA | 860 | N | |
| Static axial stiffness, preload class A | 237 | N/µm | ||
| Preload class B | GB | 1720 | N | |
| Static axial stiffness, preload class B | 325 | N/µm | ||
| Preload class C | GC | 3440 | N | |
| Static axial stiffness, preload class C | 461 | N/µm | ||
| Preload class D | GD | 6880 | N | |
| Static axial stiffness, preload class D | 678 | N/µm | ||
| Calculation factors | ||||
| Calculation factor | f | 1.32 | ||
| Calculation factor | f1 | 1 | ||
| Calculation factor | f2A | 1 | ||
| Calculation factor | f2B | 1.04 | ||
| Calculation factor | f2C | 1.09 | ||
| Calculation factor | f2D | 1.15 | ||
| Calculation factor | fHC | 1 | ||
| Calculation factor | f0 | 16.7 | ||
Mass
| Mass bearing | 8.5 | kg |