Basic static load rating and equivalent static load of bearing

Basic static load rating and equivalent static load of the seated bearing: When the basic static load rating bearing is subjected to excessive static load or impact load at 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 so-called basic static load rating refers to the static load that generates the calculated contact stress as shown below in the center of the contact surface between the rolling element and the raceway subjected to the maximum load. Under this contact stress, the total permanent deformation of the rolling elements and raceways produced is about 0.0001 times the diameter of the rolling elements. The basic static load rating of the component ball bearing is expressed by (C0 r ), and its value is shown in the dimension table. Equivalent static load refers to an imaginary load. When the seated 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 radial static load (P0 r) of a seated ball bearing for components can be calculated by the following formula (take the larger value). P0r u003d 0.6Fr + 0.5 Fa P0r u003d Fr. In the above formula, P0r: radial equivalent static load, N Fr: radial load, N Fa: axial load, N. Safety factor: The allowable equivalent static load of the bearing depends on the basic static load rating of the bearing. However, with the different bearing performance requirements and bearing service conditions, the bearing service limit determined by the above-mentioned permanent deformation (partial depression) will change. Therefore, in order to analyze the safety of the basic static load rating, a safety factor was established based on past experience. f su003d: Safety factor (refer to Table 5.6) C0r: Radial basic static load rating, NP0r: Radial equivalent static load, N. Table 5.6 Safety factor fs (recommended) Use conditions (minimum) General rotation accuracy requirements are high 2 General use conditions 1 Impact load 1.5 General use conditions 0.5 Impact load or non-uniform load 1 P0r ＝ 0.6Fr ＋ 0.5 Fa ＝ 0r 0r It rotates infrequently and sometimes swings.