| In practical engineering, uncertain characteristics exist in nearly all the couplingelements of complex rotor system. The dynamic parameters of mechanical parts, such asdimension, Young’s Modulus, density, Poisson’s ratio etc, is usually probabilistic due todesign tolerance, assembly errors, wear and operating temperature. Previous modelingmethods of mechanical systems usually ignored the probabilistic characteristics of thedynamic parameters. So they have some limitations. To study the coupling unit probabilisticparameters’s effect to the performance of a complex rotor system dynamics, this paper focuson the study of the coupling unit dynamics model with random parameter. The main work ofthe text is follows:1Taking the Rolling ball bearings and cylindrical roller bearings as the main object ofstudy. The oil film thickness of ball bearings have been analyzed with the theory of Hertzcontact deformation and the EHL. A deterministic model about the overall stiffness andoverall damping of the rolling is proposed. To research the model’s random factor, therolling’s overall stiffness and damping’s Random parameter model were established.2By analyzing the positional relationship of the various parts in rolling bearing and themotion state,a ball bearing as a three DOF mass-spring-damper system has been set up. Therolling bearing dynamics equations with random parameters is established.3In a complex rotor system, the coupler is common coupling element. In this paper, thediaphragm coupler’s axial stiffness, radial stiffness and rotation stiffness calculation formulaare studied, and it’s random parameter model was established.4With the MATLAB program, the coupling element’s random parameters of a doublerotor-bearing system were analyzed through the Monte-Carlo numerical simulation method.The coupling element’s quality, stiffness and damping coefficient are consisted as randomparameters, the double rotor system’s average eigenvalues vary with the variation coefficientis described. |
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