Hydrostatic Fluid Bearing Cells Without Curved Plate Machining

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Solution Overview

Problem

The existing method for fabricating hydrostatic fluid bearings with cylindrical stators requires accurate calculation and complex machining of a plane metal plate, which is difficult to curve and machine, and involves different materials with varying hardnesses, making the process intricate and prone to errors.

Innovation Solution

A method involving direct deposition of a metal coating on the stator's inside surface, impregnation with self-lubricating composite material, machining cells and orifices in the coating, and optional heat treatment and re-boring, simplifying the process and improving accuracy and adherence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a plane metal plate is used to receive composite material, then the bearing can be fabricated with self-lubricating layer, but the plate requires accurate calculation of dimensions and difficult curving operation

Engineering Contradiction:

Improveself-lubricating layer integrityVSAvoidplate curving difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of curving a flat plate into a cylindrical shape, the invention applies coating material directly onto the cylindrical stator surface in its final curved form. This inverts the traditional sequence of flattening then curving, eliminating the difficult curving operation while maintaining the self-lubricating layer integrity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The coating is applied directly onto the pre-formed cylindrical stator surface, performing the coating action before any potential curving would be needed. This preliminary application on the final shape avoids subsequent deformation operations and ensures accurate cell geometry from the start.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If a plane metal plate is curved into split ring, then the bearing structure can be assembled, but the curving operation affects the shape of cells

Engineering Contradiction:

Improveassembly feasibilityVSAvoidcell shape accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Rather than curving a flat plate and then machining cells, the invention machines cells directly into the coating on the curved stator surface. This inverts the sequence to preserve cell shape accuracy while still achieving the necessary curved geometry for assembly.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If orifices are machined through sandwich of stator, plate, and composite material, then fluid paths can be created, but machining becomes complex due to different hardnesses

Engineering Contradiction:

Improvefluid path integrityVSAvoidmachining complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention removes the intermediate plate from the material sandwich, extracting the source of machining complexity. By coating directly onto the stator, only two materials (stator and coating) need to be machined instead of three, simplifying the orifice machining process while maintaining fluid path integrity.

Inventive Principle:

Principle #2Taking out (Extraction)

4Ease of manufacture

If coating is applied directly on stator surface, then plate curving is eliminated, but coating adhesion to stator must be ensured

Engineering Contradiction:

Improveprocess simplificationVSAvoidcoating adhesion

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The invention changes the physical-chemical parameters of the coating application process to ensure adhesion. By controlling coating deposition parameters (such as thermal spray temperature, particle velocity, or chemical vapor deposition conditions), strong adhesion between the coating and stator surface is achieved despite the direct application method.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method eliminates the need for a curved plate, ensures accurate cell shape and simplified machining, and enhances the bearing's durability and tolerance to shaft-bearing contacts, allowing for easier transient operations and improved endurance.

Implementation Method 1

depositing a coating of metal material on the inside surface of the body of the stator

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Implementation Method 2

impregnating said coating with a self-lubricating composite material

Methodology Applied

Scientific EffectImpregnation: Absorption (physical)

Data Source

PatentUS10995796B2Method for producing a hydrostatic fluid bearing with cells

Publication Date: 2021.05.04 SAFRAN AIRCRAFT ENGINES SAS

AI summary

The method comprises depositing a coating of metal material on the inside surface of the body (4) of the stator (36), impregnating said coating with a self-lubricating composite material (20), machining internal cells (28) in the thickness of the coating (10), and machining orifices (34) leading into the cells.