When the motor bearing is subjected to too much static load or is subjected to an impact load at a very low speed, the contact surface of the rolling element and the raceway will produce local permanent deformation. The amount of deformation increases with the increase of the load, if it exceeds a certain limit, it will affect the normal rotation. The basic static load rating refers to the static load that produces the following calculated contact stress at the center of the contact surface between the rolling element and the raceway that is subjected to the maximum load. Self-aligning ball bearings: 4600M {469kgf/ }Other ball bearings.. .4200M {429kgf/ }Roller bearings. 4000M {408kgf/ }Under these contact stresses, the total permanent deformation of the rolling elements and raceways is about the rolling elements 0.0001 times the diameter. The basic static load rating of a radial bearing is called the radial basic static load rating and is represented by Cor. In the following cases, the size of the bearing should be selected according to the rated static load, instead of calculating the life of the bearing according to the rated dynamic load 1) The bearing is static and under continuous or intermittent impact load; 2) The bearing is under load The speed of the bearing is less than 10rpm; or only a short bearing life is required. As a result, the bearing selected according to the rated dynamic load may be seriously overloaded; 3) The bearing is rotating, but it needs to bear a lot of Heavy impact load Equivalent static load is an imaginary load. When the bearing is stationary or the speed is extremely low, the center of the contact surface between the rolling element and the raceway bearing the maximum load under the imaginary load produces the same contact stress as under the actual load condition. The equivalent static load of the radial bearing adopts the radial load passing through the bearing center. The equivalent static load can be calculated by the following formula: equivalent static load calculation (1) Deep groove ball bearing equivalent static load: P0u003dFr［KN］ when Fa/Fr≤0.8 (27) P0＝0.6Fr＋0.5Fa［KN］ when Fa/Fr＞0.8 （28）（2）Calculation of equivalent static load of cylindrical roller bearing: P0＝Fr［KN］ （29）（3）Spherical roller The equivalent static load calculation of the bearing: calculated by the following two formulas, whichever is greater (30) a u003d or P Fr +Y0FPoru003dFrFa: axial load, KNY0 radial static load coefficient formula Y0 value can be checked Bearing size table. (4) Calculation of equivalent static load of angular contact ball bearings: single row angular contact ball bearings with a contact angle of 15° for single bearing or tandem configuration P0u003d0.5Fr+0.46Fa [kN] (31) When F0