Bearings, units and housings -- Super-precision bearings -- Angular contact ball bearings -- Angular contact ball bearings, super-precision -- SKF 71920 CB/P4A
71920 CB/P4A
Dimensions
| d | 100 | mm | |
| D | 140 | mm | |
| B | 20 | mm | |
| d1 | 114.92 | mm | |
| d2 | 113.16 | mm | |
| D2 | 128.7 | mm | |
| r1,2 | min. | 1.1 | mm |
| r3,4 | min. | 0.6 | mm |
| a | 28.9 | mm |
Abutment dimensions
| da | min. | 106 | mm |
| db | min. | 106 | mm |
| Da | max. | 134 | mm |
| Db | max. | 136.8 | mm |
| ra | max. | 1 | mm |
| rb | max. | 0.6 | mm |
| dn | 116.1 | mm |
Calculation data
| Basic dynamic load rating | C | 29.1 | kN | |
| Basic static load rating | C0 | 36 | kN | |
| Fatigue load limit | Pu | 0.865 | kN | |
| Attainable speed for grease lubrication | 12000 | r/min | ||
| Attainable speed for oil-air lubrication | 19000 | r/min | ||
| Ball diameter | Dw | 7.938 | mm | |
| Number of balls | z | 37 | ||
| Reference grease quantity | Gref | 9.96 | cm³ | |
| Preload and stiffness (back-to-back, face-to-face) | ||||
| Preload class A | GA | 72 | N | |
| Static axial stiffness, preload class A | 60 | N/µm | ||
| Preload class B | GB | 145 | N | |
| Static axial stiffness, preload class B | 79 | N/µm | ||
| Preload class C | GC | 430 | N | |
| Static axial stiffness, preload class C | 125 | N/µm | ||
| Calculation factors | ||||
| Calculation factor | f | 1.11 | ||
| Calculation factor | f1 | 1 | ||
| Calculation factor | f2A | 1 | ||
| Calculation factor | f2B | 1.02 | ||
| Calculation factor | f2C | 1.07 | ||
| Calculation factor | fHC | 1 | ||
| Calculation factor | f0 | 10 | ||
Mass
| Mass bearing | 0.85 | kg |