Analysis Behavior of a Rig Shafting Vibration Set Changes Bearing Parameters

Abstract

Frequently, in the design of machines, some of parameters that directly affect the rotordynamics of the machines are not accurately known. In particular, bearing stiffness support is one such parameter. Taking a rig shafting as an example, this paper studies the lateral vibration of the rig shafting with multi-degree-of-freedom by using finite element method (FEM). The FEM model is created and the eigenvalues and eigenvectors are calculated and analyzed to find natural frequencies, critical speeds, mode shapes. Then critical speeds and mode shapes are analyzed by set bearing stiffness changes. The model permitted to identify the critical speeds and bearings that have an important influence on the vibration behavior.

Effect of the Supports’ Positions on the Vibration Characteristics of a Flexible Rotor Shafting

“…Kumar and Somnath [10] theoretically studied the effects of different bearing lengths, rotor speeds, and unbalanced forces reported in the literature on the dynamic characteristics of rotor-bearing systems. Generally, the effects of bearing stiffness on the critical velocity and vibration response characteristics of shafting systems have been widely investigated [11][12][13][14], as well as the methods to optimize the bearing stiffness, damping, length, gap, and diameter to improve the overall stability of a shafting [15][16][17]. Yücel and Saruhan [18] also used the Taguchi method to test the vibration of a rotor system under different coupling configurations, disk positions, and speeds in order to determine the combination of parameters that minimize deformation due to vibration.…”

Study on the vibration characteristics of a roller-supporting horizontal centrifugal casting machine

“…One is the analytical method 6 and the other two are numerical methods, including transfer matrix method (TMM) 7–10 and finite element method (FEM). 11–14 When FEM is used, the continuous component should be discretised into a finite but very large number of degrees of freedom, and the linear deformations of the nodes of this finite element model can be approximated as a linear combination of a smaller number of shape vectors. 14 The differential equations of motion of the system can be established once the mass matrix and stiffness matrix of each element are obtained.…”