Effect of roundness error on the performance of novel gas foil conical bearings

Abstract

PurposeThe purpose of this paper is to study the effect law of roundness error on the properties of gas foil conical bearing (GFCB), and the performance of bearings with different non-circular sleeve shapes are calculated.Design/methodology/approachFor the bump-type GFCB, the nonlinear bump foil stiffness model and 1-D beam top foil stiffness model are built. On this basis, the finite element method and finite difference method are used to solve the Reynolds equation and the film thickness equation coupled, and the static and dynamic properties of GFCB are calculated. The effect law of sleeve roundness error on the static performance under different conditions is obtained. Moreover, the dynamic stiffness and damping characteristics under different errors are also studied.FindingsThe roundness error will decrease the load capacity and friction torque of GFCB, and increase the attitude angle. The error effect is more dramatic when there is larger eccentric, small nominal clearance, larger error value and more error lobes, and the static performance exhibits a periodic change in the circumferential direction. The roundness error can also decrease the direct stiffness and cross-coupled damping of GFCB, while the cross-coupled stiffness increases largely, which will reduce the bearing stability.Originality/valueThe roundness error adversely affects the static and dynamic characteristics of GFCB, which should be concerned by bearing designers, researchers and academicians.Peer reviewThe peer review history for this article is available at:https://publons.com/publon/10.1108/ILT-01-2020-0019/