Bearings, units and housings -- Super-precision bearings -- Angular contact ball bearings -- Angular contact ball bearings, super-precision -- SKF 71920 CD/P4A
71920 CD/P4A
Dimensions
| d | 100 | mm | |
| D | 140 | mm | |
| B | 20 | mm | |
| d1 | 112.3 | mm | |
| d2 | 112.3 | mm | |
| D1 | 127.7 | mm | |
| r1,2 | min. | 1.1 | mm |
| r3,4 | min. | 0.6 | mm |
| a | 26.1 | mm |
Abutment dimensions
| da | min. | 106 | mm |
| db | min. | 106 | mm |
| Da | max. | 134 | mm |
| Db | max. | 136 | mm |
| ra | max. | 1 | mm |
| rb | max. | 0.6 | mm |
| dn | 115.6 | mm |
Calculation data
| Basic dynamic load rating | C | 60.5 | kN | |
| Basic static load rating | C0 | 65.5 | kN | |
| Fatigue load limit | Pu | 2.55 | kN | |
| Attainable speed for grease lubrication | 8500 | r/min | ||
| Attainable speed for oil-air lubrication | 14000 | r/min | ||
| Ball diameter | Dw | 12.7 | mm | |
| Number of balls | z | 26 | ||
| Reference grease quantity | Gref | 10.5 | cm³ | |
| Preload and stiffness (back-to-back, face-to-face) | ||||
| Preload class A | GA | 230 | N | |
| Static axial stiffness, preload class A | 107 | N/µm | ||
| Preload class B | GB | 460 | N | |
| Static axial stiffness, preload class B | 147 | N/µm | ||
| Preload class C | GC | 920 | N | |
| Static axial stiffness, preload class C | 209 | N/µm | ||
| Preload class D | GD | 1840 | N | |
| Static axial stiffness, preload class D | 306 | N/µm | ||
| Calculation factors | ||||
| Calculation factor | f | 1.23 | ||
| 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 | 16.3 | ||
Mass
| Mass bearing | 0.8 | kg |