| High speed machining is the trend of the manufacturing. High speed machine tool spindles are key component of high speed machine tools. With the increasing of cutting speed, the requirements of performance of spindle system are very high. To the high speed machine tool, dynamic life theory of processing dynamic characteristic analysis and studying high speed tool bearing has become the pressing requirement of the whole machine development. On the basis of previous studies for high-speed bearings, considered all kinds of factors influencing interaction forces between all components of the high-speed bearings, using ball bearing dynamic analysis program BBDY and related program programmed by myself, this paper analyzes all kinds of influencing factors to bearing dynamic life theory and establishes the dynamic life analysis theory. This paper finishes the works as follows:1. Principal axis bearing dynamic model is established. First of all, assume ferrule has 6 degrees of freedom, considered the upright force between bearing ferrule and ball and the influences of working gap and oil film, the elasticity theory and Hertz contact theory are applied to obtain the static equilibrium equations of the ring; Secondly, assume the ball has 6 degrees of freedom, considered the contact and rub force between ball and roll path interface, the rub force of entry area, the force between ball and cage and resistance from admixture of oil and gas, the Hertz contact theory is applied to establish simulative dynamics equilibrium equations of the ball; Thirdly, assume cage has 3 degrees of freedom, considered some interaction forces between cage and ball, cage and ring guiding surface and agitate resistance from cage, fuzzy impact theory is applied to establish dynamics equations of cage; finally, equilibrium equations of the whole bearings are established. According to the characteristic of equilibrium equations of bearing system, the simultaneous solutions of the equations of the bearing motion are found by using the Newton-Raphson(N-R)method and 4th order Rung-Kutta integration.2. The influencing factors for principal axis bearing are analyzed. Firstly, dynamic characteristic of steel ball and ceramic ball are analyzed by using ball bearing dynamic analysis program BBDY and related program programmed by myself. Based on the parameters comparison of these two materials, such as force, moment, rotate speed, thickness of oil film and revolving and rolling parallel, dynamic characteristic relationship between them is studied; At the same time, compared with data of real situation on the existing literature, the veracity of BBDY programs is verified; Secondly, dynamic characteristics of the three different cages are analyzed. Based on BBDY programs and programs programmed by myself, and at the varieties of the contact force between the ball and the cage, rotate speed, the lead clearance of the cage and hole, centroid movement track is obtained. According to the characteristic of the track, dynamic characteristic of cage is analyzed; furthermore, the relationship between all kinds of dynamics parameters and dynamic life of bearings are obtained.3.Dynamic life theory for bearing is established. Firstly, the development of the fatigue life of the bearing is introduced. Then, wear life calculating method of the bearing, especially the way about the wear and tear interrelated to the style mentioned in the paper, are introduced. Finally, according to the analysis of the computations in this paper, a dynamic life theory is established, which provides basis for the development of the theory of high speed angular contact bearing.
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