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| | | 1 | | 2 Recommendations | | 3 Product data | | |
| | | Product information | | |
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| | | Page | | Bearing size | | Page | | |
| | | 3 | | | 32 | | |
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| | | Selection of bearing size | | |
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| | | Bearing life | | |
| | | aSKFfactor The aSKF factor represents a very complex relationship between various influencing factors including contamination and lubrication. Lubrication conditions are expressed by the viscosity ratio k. Values of aSKF can be obtained from Diagram M for different values of r|c (Pu/P) and k. For standard spherical roller bearings, the values in black on the x axis should be used and for Explorer bearings the values in blue on the x axis. In fact, for Explorer spherical roller bearings it has been found appropriate to multiply r|c (Pu/P) by 1,4 as an expression of the life extending refinements of these industrial bearings, and the blue values correspond to this. Diagram m has been drawn up for a safety factor commonly used in fatigue life considerations and is valid for lubricants without EP additives. If a lubricant containing such additives is used, reference should be made to the SKF General Catalogue or the SKF Interactive Engineering Catalogue on CD-ROM or the Internet (www.skf.com). | | Equivalent dynamic bearing load | | |
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| | | The life-extending improvements embodied in SKF Explorer spherical roller bearings can best be understood using the SKF Life Method. This calculation method constitutes an extension of the fatigue life theory developed by Lundberg and Palmgren and is better able to predict bearing life. The Life Method was first presented as the SKF New Life Theory in the SKF General Catalogue 4000 in 1989. For roller bearings | | |
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| | | P = Fr + YiFa P = 0,67 Fr + Y2Fa | | when Fa/Fr < e when Fa/Fr > e | | |
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| | | | | | | | | | where | | | | | P | = equivalent dynamic bearing | | | | | load, kN | | | | Fr | | | | | Fa | = actual axial bearing load, kN | | | | Y1, Y2 | = axial load factors for the | | | | | bearings | | | | e | = calculation factor | | | | | | | | | |
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| | | Lnaa = a1 aSKF Li0 | | |
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| | | Appropriate values of the factors e, Y-| and Y2 will be found in the bearing tables for each individual bearing. | | |
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| | | C\10/3 P / | | |
| | | Lnaa = a1 asKF | | |
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| | | If the speed is constant, it is often preferable to calculate the life expressed in operating hours using | | |
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| | | 1 000 000 /C\10/3 60n (PI | | |
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| | | Lnaah = a1 aSKF | | |
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| | | where Lnaa = the adjusted rating life according to the SKF Life Method, million revolutions Lnaah = the adjusted rating life according to the SKF Life Method, operating hours L10 = basic rating life, million revolutions a1 = life adjustment factor for reliability Table H ) aSKF = life adjustment factor based on SKF Life Method Diagram H ) C = basic dynamic load rating, kN P = equivalent dynamic bearing load, kN n = rotational speed, r/min | | |
| | | Life adjustment factor a1 Tab\eA\ | | |
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| | | Reliability | | |
| | | Factor a1 | | |
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| | | 90 95 96 97 98 99 | | 1 0,62 0,53 0,44 0,33 0,21 | | |
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