Seal Ring Coating Masking for Isotropic Sealing Band Finishing

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Solution Overview

Problem

Existing seal ring technologies face challenges in maintaining a durable, corrosion-resistant seal under high-pressure and high-speed conditions, particularly in isotropically finished components where corrosion coatings may be compromised during the finishing process.

Innovation Solution

A method of making a seal ring with an isotropically finished sealing band, where a layer of coating composition is applied before isotropic finishing, and a masking member is used to protect non-finished areas, ensuring the coating remains intact and the sealing band achieves a consistent surface finish of 0.3 micrometers Ra or less.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a corrosion coating is applied to the seal ring before isotropic finishing, then corrosion resistance is improved, but the coating may be removed during the isotropic finishing process

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidcoating integrity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The corrosion coating is applied to the seal ring before the isotropic finishing process. This preliminary application allows the coating to be established on the surface prior to finishing, and the process parameters are controlled to prevent removal of the coating while still achieving the desired surface finish on the sealing band.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the sealing band is polished to achieve a consistent surface finish of 0.3 micrometers Ra or less, then sealing performance is improved, but the surface stress and potential coating removal increase

Engineering Contradiction:
Improvesurface finishVSAvoidsurface stress
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The isotropic finishing process uses controlled parameters including acid concentration, temperature, and agitation to achieve the desired surface finish of 0.3 micrometers Ra or less. By optimizing these parameters, the process removes surface irregularities and reduces stress concentrations while preventing excessive material removal or coating damage.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a mask is used to protect non-finished areas during isotropic finishing, then coating protection is improved, but device complexity increases

Engineering Contradiction:
Improvecoating protectionVSAvoidmasking system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The masking member is designed to selectively protect only the non-sealing portions of the seal ring during isotropic finishing. The mask allows the sealing band to be exposed for finishing while protecting other areas where the coating should remain intact. This localized approach minimizes the complexity of the masking system while achieving the desired differential treatment.

Inventive Principle:
Principle #3Local quality

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

The method enhances the corrosion resistance and durability of the seal ring, maintaining a fluid-tight seal under severe conditions while preventing coating removal during isotropic finishing, thus extending the seal ring's lifespan.

Implementation Method 1

a mask is placed over at least an area of the layer of coating composition applied to the exterior surface of the seal ring

Methodology Applied
Scientific EffectPhysical barrier protection:

Implementation Method 2

The sealing band is polished by subjecting the sealing band to an isotropic finishing process

Methodology Applied
Scientific EffectIsotropic finishing:

Implementation Method 3

The layer of coating composition is formulated to withstand the isotropic finishing process and to help increase the corrosion resistance of the seal ring

Methodology Applied
Scientific EffectCorrosion resistance:

Data Source

PatentEP3931471B1Method and appliance for making isotropically finished seal ring of seal assembly for machine
Publication Date: 2024.07.03 CATERPILLAR INC
  • EP3931471B1 patent drawingFigure 1
  • EP3931471B1 patent drawingFigure 2
  • EP3931471B1 patent drawingFigure 3~4

AI summary

A seal ring (111, 112) for a seal assembly (30, 36) includes a body (240) and a seal flange (137). The body (240) is generally cylindrical, extending along a longitudinal axis (LA) between a load end (131) and a seal end (132). The seal flange (137) is disposed adjacent the seal end (132) of the body (240), projecting radially in a circumscribing manner from the body (240). The seal flange (137) includes a sealing face (136) having a sealing band (140) for sealing contact with a mating seal ring (111, 112). A layer (142) of coating composition formulated to help increase the corrosion resistance of the seal ring (111, 112) is applied to at least the body (240). A mask (300, 400) is applied to the seal ring (111, 112) to cover at least a portion of the seal ring (111, 112) having the layer (142) of coating composition applied thereto such that the sealing band (140) remains exposed. The sealing band (140) is polished by an isotropic finishing process. The mask (300, 400) is removed after the sealing band (140) is isotropically polished.