A numerical method for the stiffness of a kind of the pivot point of tilting pad bearings

Purpose This study aims to propose a numerical method which was applied to investigate the pivot point stiffness of tilting pad bearings. A method combining the nonlinear contact effect and linear deformation was proposed. This type of pivot point is non-conical and has a hyperbolic or cylindrical geometric structure. Design/methodology/approach First, according to the Hertz contact theory, considering the nonlinear effects, the deformation of the pivot point and the shape parameters of the contact area under the bearing force condition were calculated. Subsequently, three-dimensional models of the bearing support with the contact area were created, and a finite element simulation was performed. Displacement boundary conditions were set, and the bearing force on the contact area was used to obtain the deformation results of the bearing support. Findings By combining the deformations of the Hertz contact nonlinear calculation and the finite element linear calculation and considering the bearing force, the expression for the pivot stiffness of the tilting pad bearing can be obtained. Originality/value Taking the rotor of an industrial compressor as an example, not only does the pivot stiffness influence the critical speed of the rotor, but the effectiveness of this numerical method has also been demonstrated.