Bearings, units and housings -- Super-precision bearings -- Angular contact ball bearings -- Angular contact ball bearings, super-precision -- SKF 71820 CD/P4
71820 CD/P4
Dimensions
| d | 100 | mm | |
| D | 125 | mm | |
| B | 13 | mm | |
| d1 | 108.2 | mm | |
| d2 | 108.2 | mm | |
| D1 | 117 | mm | |
| r1,2 | min. | 1 | mm |
| r3,4 | min. | 0.3 | mm |
| a | 21.6 | mm |
Abutment dimensions
| da | min. | 104.6 | mm |
| db | min. | 104.6 | mm |
| Da | max. | 120.4 | mm |
| Db | max. | 123 | mm |
| ra | max. | 1 | mm |
| rb | max. | 0.3 | mm |
| dn | 109.1 | mm |
Calculation data
| Basic dynamic load rating | C | 22.5 | kN | |
| Basic static load rating | C0 | 29 | kN | |
| Fatigue load limit | Pu | 1.16 | kN | |
| Attainable speed for grease lubrication | 9000 | r/min | ||
| Attainable speed for oil-air lubrication | 14000 | r/min | ||
| Ball diameter | Dw | 7.144 | mm | |
| Number of balls | z | 34 | ||
| Reference grease quantity | Gref | 3.2 | cm³ | |
| Preload and stiffness (back-to-back, face-to-face) | ||||
| Preload class A | GA | 120 | N | |
| Static axial stiffness, preload class A | 90 | N/µm | ||
| Preload class B | GB | 360 | N | |
| Static axial stiffness, preload class B | 156 | N/µm | ||
| Preload class C | GC | 720 | N | |
| Static axial stiffness, preload class C | 231 | N/µm | ||
| Calculation factors | ||||
| Calculation factor | f | 1.4 | ||
| Calculation factor | f1 | 1 | ||
| Calculation factor | f2A | 1 | ||
| Calculation factor | f2B | 1.09 | ||
| Calculation factor | f2C | 1.16 | ||
| Calculation factor | fHC | 1 | ||
| Calculation factor | f0 | 17.4 | ||
Mass
| Mass bearing | 0.31 | kg |