Method for calculating equivalent stiffness and equivalent damping of fluid fulcrum tilting pad sliding bearing

Abstract

The invention discloses a method for calculating equivalent stiffness and equivalent damping of a fluid fulcrum tilting pad sliding bearing. The existing calculation method for the equivalent stiffness and the equivalent damping of the fluid fulcrum tilting pad bearing has a great improvement space. According to the method, equivalent dynamic models of a journal, an inner oil film, an outer oil film and a tilting-pad sliding bearing in x and y directions are established, a motion differential equation is established according to force balance, an oil film force calculation formula is expanded in a Taylor series mode, high-order variables are omitted, displacement and acceleration of the journal and a tile in the x and y directions under three sets of excitation force are measured, and the displacement and acceleration of the journal and the tile in the y and x directions are calculated. And constructing a transfer function, substituting the transfer function into a matrix equation expressed by amplitude and phase, and solving to obtain a rigidity coefficient and a damping coefficient of the fluid fulcrum tilting pad sliding bearing. According to the influence of the damping hole, the rigidity coefficient and the damping coefficient are calculated through a transfer function method, and compared with calculation in a fluid form, the calculation process is more concise, and calculation is more comprehensive and accurate.

Description

technical field [0001] The invention belongs to the technical field of bearings, and relates to a method for calculating the equivalent stiffness and equivalent damping of a fluid fulcrum tilting pad sliding bearing. Background technique [0002] The fluid fulcrum tilting pad bearing cancels the mechanical fulcrum of the traditional tilting pad bearing, and opens a concave surface on the back of the pad, and there is a small hole in the middle of the concave surface. When the rotor system is running, the lubricating oil between the main shaft and the bearing pad passes through the middle of the bearing pad. The small hole enters between the back of the bearing pad and the bearing housing, thus forming two layers of oil film inside and outside. The dynamic characteristics of the oil film (stiffness coefficient and damping coefficient) have a great influence on the critical speed unbalance response, stability and coupling vibration of the rotating shaft system and the base of ...

AI Technical Summary

Problems solved by technology

The patent document with the publication number CN 102323058 discloses a method for identifying the bearing load by measuring the strain signals at different sections of the rotating shaft, which requires the arrangement of a large number of strain measuring points, and the entire shafting structure needs to be completed by modeling, which will cause large measurement errors

The patent document with publication number CN 110296837 discloses a sliding bearing load measurement method based on bearing pad deformation. The strain measuring point is installed on the bearing pad, and the measurement requires bearing pad deformation data. For tilting pad bearings such as pad flexible bearings, measurement will produce error

In short, the measurement of the data required by the existing calculation method is relatively difficult, and there is still a lot of room for improvement in the calculation method of the equivalent stiffness and equivalent damping of the fluid fulcrum tilting pad bearing

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