Purpose

The porous bearings are commonly used in slider thrust bearings owing to their self-lubricating properties and cost effectiveness as compared to conventional hydrodynamic bearings. The purpose of this paper is to numerically investigate usefulness of porous layer in hydrostatic thrust bearing operating with magnetic fluid. The effect of magnetic field and permeability has been analysed on steady-state (film pressure, film reaction and lubricant flow rate) and rotor-dynamic (stiffness and damping) parameters of bearing.

Design/methodology/approach

Finite element approach is used to obtain numerical solution of flow governing equations (Magneto-hydrodynamics Reynolds equation, Darcy law and capillary equation) for computing abovementioned performance indices. Finite element method formulation converts elliptical Reynolds equation into set of algebraic equation that are solved using Gauss–Seidel method.

Findings

It has been reported that porosity has limited but adverse effects on performance parameters of bearing. The adverse effects of porosity can be minimized by using a circular pocket for achieving better steady-state response and an annular/elliptical pocket, for having better rotor-dynamic response. The use of magnetic fluid is found to be substantially enhancing the fluid film reaction (53%) and damping parameters (55%).

Practical implications

The present work recommends use of circular pocket for achieving better steady-state performance indices. However, annular and elliptical pockets should be preferred, when design criteria for the bearing are better rotor-dynamic performance.

Originality/value

This study deals with influence of magnetic fluid, porosity and pocket shape on rotor-dynamic performance of externally pressurized thrust bearing.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0289/

中文翻译：

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磁场作用下的多孔静压推力轴承的转子动力学性能

目的

多孔轴承由于其自润滑性能和与常规流体动力轴承相比的成本效益而通常用于滑动推力轴承。本文的目的是数值研究多孔层在以磁性流体运行的静压推力轴承中的有用性。分析了磁场和磁导率对轴承的稳态（膜压力，膜反应和润滑剂流速）和转子动态参数（刚度和阻尼）的影响。

设计/方法/方法

使用有限元方法获得流量控制方程（磁流体动力学雷诺方程，达西定律和毛细管方程）的数值解，以计算上述性能指标。有限元方法公式将椭圆形雷诺方程转换为代数方程组，这些方程组可通过高斯-赛德尔（Gauss-Seidel）方法求解。

发现

据报道，孔隙率对轴承的性能参数影响有限，但有不利影响。通过使用圆形凹穴以获得更好的稳态响应，并使用环形/椭圆形凹穴，从而具有更好的转子动态响应，可以将孔隙率的不利影响降至最低。发现使用磁性流体实质上增强了流体膜反应（53％）和阻尼参数（55％）。

实际影响

本工作建议使用圆形袋，以获得更好的稳态性能指标。但是，当轴承的设计标准是更好的转子动力学性能时，应首选环形和椭圆形的腔。

创意/价值

这项研究涉及磁流体，孔隙率和凹穴形状对外部加压推力轴承转子动力学性能的影响。

同行评审

本文的同行评审历史记录可在以下网址获得：https://publons.com/publon/10.1108/ILT-07-2020-0289/