US 4,227,752 A · Staged bearing surface compliance for hydrodynamic fluid bearing

Abstract

A hydrodynamic fluid bearing includes a pivoted shoe which can tilt in response to the hydrodynamic fluid forces generated between the bearing surfaces, and a locally conformable bearing layer attached to the shoe facing the opposing bearing surface. The pivoted shoe can pivot to conform to changes in the pitch of the opposing bearing surface and can tilt to the correct slope to generate the hydrodynamic supporting fluid wedge, and can also conform to the shape of the opposing bearing surface if it becomes thermally distorted or "dished". The compliant layer at the top surface of the shoe can conform to smaller area bearing irregularities, and in addition, can locally conform under hydrodynamic forces to assume the ideal configuration to generate the optimum hydrodynamic wedge. The support on which the pivoted shoe is mounted can itself be pivoted on a gimbal ring to provide large area compliance with the bearing surface to follow, if necessary, precession or other large scale runout of the bearing surface. Each stage of the compliant support can be designed to give the stiffness and damping best suited for that stage of support.

Claims11

Dependent claims

A resilient compliant hydrodynamic fluid bearing, comprising:

a stationary member and a relatively movable member, said members defining therebetween a gap;
a plurality of pads supported by said stationary member for tilting about axes parallel to the plane of said stationary member;
each of said pads having a compliant bearing layer in opposed relationship to an opposing bearing surface on said movable member;
said compliant bearing layer including a thin, flexible bearing sheet having a bearing surface on one side thereof facing said opposing bearing surface, and a resilient, compliant supporting structure underlying said bearing sheet on the other side thereof for resiliently supporting said bearing sheet while permitting local deflections thereof;
and
flexure mounting means for tiltably mounting said pads on said stationary member to enable said pads to conform to large scale changes in the slope of said opposing bearing surface and to automatically maintain the correct large scale orientation of said bearing sheet while said compliant bearing layer resiliently deflects to respond to hydrodynamic fluid forces existing between said bearing surfaces to cause said bearing sheet to assume a profile that is conducive to the establishment and maintenance of supporting hydrodynamic fluid films between said bearing surface, said flexure having an angular stiffness greater than one tenth of the angular stiffness of said compliant supporting structure.

3 more elements

A resilient compliant hydrodynamic fluid bearing, for dynamically supporting a high speed rotating rotor having a rotor bearing surface, comprising;

a flexible bearing sheet having a bearing surface in opposed relationship to said rotor bearing surface;
a supporting structure for supporting said sheet bearing surface, and including a plurality of support stages arranged in series;
said support stages compliantly supporting said bearing sheet so that said sheet bearing surface can conform to said rotor bearing surface and deflect under the influence of the hydrodynamic fluid forces exerted by the fluid films between said bearing surfaces to establish and maintain the correct slope of said sheet bearing surface with respect to said rotor bearing surface;
one of said support stages supporting the next support stage and indirectly supporting the entire sheet bearing surface, said one support stage including at least one first form support modality;
said next support stage operatively supporting a large sheet bearing surface and including more than one second form support modality;
said first form support modality supporting more than one second form modality so the area of said sheet bearing surface operatively supported by each of said first form modalities is greater than the area of said sheet bearing surface operatively supported by each of said second form support modalities;
said one support stage having an angular stiffness greater than about one tenth of the angular stiffness of said next support stage.

4 more elements

Dependencies are inferred from the claim text.

Staged bearing surface compliance for hydrodynamic fluid bearing

Life of this patent

Staged bearing surface compliance for hydrodynamic fluid bearing

Life of this patent

Abstract

Claims11