| Rolling bearing is one of the most important parts of shafting mechanical parts.It has the advantages of simple structure,small friction,stable operation and long service life.Among them,the angular contact ball bearing can simultaneously bear the combined effects of axial force,radial force and overturning moment,so it is widely used in various shafting systems?such as machine tool spindle system?.With the advancement of the times and the development of science and technology,it is more and more important for its high-precision design and calculation.In the high-speed machining process,the centrifugal force of the ball bearing and the gyroscopic moment,and the geometric error of the ball bearing itself will affect the precision of the machining to some extent.In this paper,the dynamic performance of precision ball bearings will be studied on the basis of centrifugal force,gyro moment and geometric error of the ball and inner ring and outer ring raceway.Firstly,this paper analyzes the classical ball bearing dynamics theory,Hertz contact theory,ball bearing geometric error analysis and measurement,puts forward the shortcomings and defects,and introduces the mathematical calculation software MATLAB used in this paper.Based on the classical bearing dynamics model,considering the centrifugal force and the gyroscopic moment,and the geometric error?spherical error of the ball,axial and radial waviness of the inner and outer ring raceways,the waviness of the ball,etc.?,the ball bearing dynamics model is established.The ball bearing dynamics model was modeled and compiled by MATLAB software.Then,taking the angular contact ball bearing 7218 as an example,considering the preload of the ball bearing,using the Newton-Raphson iterative algorithm,the unknown of the nonlinear equation in the mathematical model(the relative positional parameters of the four positions between the ball and the inner and outer ring racewaysXa N?Xr N??iN and ?oN.And the calculation of the five displacement components x?y?z??y and ?z),respectively,the force between the inner race of the ball bearing and the ball of the inner race rotation type?the inner ring rotates and the outer ring is fixed?is considered and considered without considering the geometric error,and processed and analyzed.Finally,the fatigue life of the ball bearing is predicted by the classical L-P theory and the improved L-P theory.The fatigue life of the bearing under the two theories is considered and considered without considering the geometric error.The relevant data obtained were processed and analyzed,and the influence of the geometric error of the ball bearing on the fatigue life of the ball bearing under the two fatigue life theories was obtained. |
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