US 4,277,113 A · Composite material compliant bearing element

Abstract

A compliant fluid film bearing includes a thin, flexible bearing sheet supported on a resilient bump-form support member which is divided into multiple adjacent strips. The bearing sheet and support member are each formed of a composite material made of Inconel X-750 and copper. The Inconel sheet, in annealed condition, is cut and formed in the desired shape and is coated with copper. The sheet is heat treated in an oxygen-free atmosphere to give the Inconel the small grain size for the desired properties of strength and hardness. During the heat treatment, the copper diffuses into the Inconel, producing at the end a composite material of Inconel X-750 having a diffusion of copper into its top portion such that the top surface is about 100% copper, and the copper fraction decreases exponentially with the depth into the Inconel sheet. The bearing elements formed of this composite material provide improved coulomb and viscous damping and improved bearing load capacity and stability at high temperature and speed.

Claims21

Dependent claims

A compliant fluid film bearing for dynamically supporting a rotating rotor, comprising:

a mounting member mounted in coaxial relationship to the rotational axis of said rotor and having a surface facing a bearing surface of said rotor;
a compliant support element fastened to said surface of said mounting member, said compliant support element including a metal support sheet having a plurality of resilient support elevations projecting therefrom;
a bearing sheet lying between said support element and the bearing surface of said rotor;
said support element formed of a composite material having a first layer of metal in engagement with said mounting member, and an overlying layer of metal in engagement with said bearing sheet and bonded to said first layer, said overlying layer having a coefficient of thermal expansion greater than the coefficient of thermal expansion of said first layer;
whereby a decrease in the stiffness of the material of the support element with increasing temperature is compensated for by an increase in stiffness of said elevations by virtue of the difference in coefficients of thermal expansion of the materials of the first and overlying layers.

2 more elements

A compliant hydrodynamic fluid film bearing for dynamically supporting a rotating rotor, comprising:

a flexible bearing sheet lying in bearing relationship to said rotor, said sheet having a front bearing surface facing a bearing surface on said rotor, and having a back surface on the side of said bearing sheet opposite said front bearing surface.
a stationary mounting member positioned adjacent and coaxially to the axis of said rotor for operatively supporting said rotor;
a compliant support element attached to said stationary mounting member and resiliently supporting said bearing sheet;
said flexible bearing sheet being formed of a composite material, having a base layer of strong springy metal, and a cladding layer of metal having a coefficient of thermal expansion greater than that of said base layer metal, said cladding layer being on the side of said base layer which is proximate said front bearing surface;
said cladding layer having a thickness and coefficient of thermal expansion with respect to said base layer that it causes said bearing sheet to assume a humped shape, convex toward said rotor bearing surface;
whereby said rotor, when rotating over said bearing sheet at operating speed, generates heat and a hydrodynamic supporting fluid film over said bearing sheet, said heat causing said bearing sheet to expand toward its humped shape, and said hydrodynamic fluid film depressing said bearing sheet toward a concave shape with respect to said rotor bearing surface, such that the resultant shape of said bearing sheet is a crown shape which is convex with respect to said rotor bearing surface.

3 more elements

Dependencies are inferred from the claim text.

Composite material compliant bearing element

Life of this patent

Composite material compliant bearing element

Life of this patent

Abstract

Claims21