Rolling Bearing Metal Coating Without Sandblasting Damage

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Solution Overview

Problem

Existing methods for applying metal coatings to rolling bearing components, such as flame spray galvanizing, require roughening the surface through sandblasting, which can damage the components, lead to poor adhesion, and result in porous, uneven layers with inadequate corrosion resistance, while also affecting shape and position tolerances.

Innovation Solution

A high-pressure cold spray process is used to apply a metal coating directly to non-sandblasted surfaces, achieving strong adhesion and a dense, non-porous layer without the need for surface roughening, allowing for precise application and improved corrosion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flame-spray galvanizing is used to apply metal coating, then corrosion protection is improved, but the surface requires sandblasting which damages the rolling bearing component and impairs shape and position tolerances

Engineering Contradiction:
Improvecorrosion protectionVSAvoidshape and position tolerances
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the fundamental parameters of the coating process by using cold spray technology instead of flame spray. This eliminates the need for sandblasting surface preparation while achieving equivalent or superior corrosion protection, thereby preserving the original surface geometry and tolerances

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the thermal-mechanical flame spray process with a cold spray process that uses kinetic energy of particles rather than thermal energy. This substitution eliminates the need for mechanical sandblasting preparation while maintaining coating adhesion and corrosion protection

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If sandblasting is performed to roughen the surface for coating adhesion, then coating adhesion is improved, but sandblasting particles can damage the surface and enter the bearing causing premature failure

Engineering Contradiction:
Improvecoating adhesionVSAvoidsurface damage and contamination
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention replaces mechanical sandblasting with a cold spray process that achieves adhesion through kinetic energy impact and metallurgical bonding. The cold spray particles are controlled and do not leave harmful residues, eliminating the contamination risk while maintaining strong coating adhesion

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the surface preparation parameter from mechanical roughening to a cleaner process that relies on the cold spray process parameters (particle velocity, temperature, pressure) to achieve adhesion without compromising surface integrity

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If flame-spray galvanizing is applied without wraparound coating, then the coating is not continuous and is vulnerable at edges causing flaking

Engineering Contradiction:
Improvecoating application simplicityVSAvoidcoating continuity and edge protection
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cold spray process inherently creates a more continuous and adherent coating compared to flame spray. The coating can be applied more selectively without requiring wraparound coverage, as the cold spray particles bond more effectively and create a continuous protective layer even on flat surfaces

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Quantity of substance

If flame-spray galvanizing is used, then the zinc layer is porous and sponge-like with poor corrosion resistance requiring additional sealing paint

Engineering Contradiction:
Improvezinc coating applicationVSAvoidcorrosion and chemical resistance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The cold spray process replaces flame spray to create a dense, non-porous zinc coating. The controlled particle deposition and bonding mechanism eliminates the sponge-like structure inherent in flame spray, providing inherent corrosion resistance without requiring additional sealing paints

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the coating process parameters to produce a dense microstructure. The cold spray process parameters (lower temperature, higher particle velocity, controlled pressure) result in a compact, non-porous coating structure that inherently resists corrosion and chemical attack

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

The method allows for the application of a stable, non-porous metal coating with high adhesion values, maintaining the original shape and position tolerances of the components, reducing the risk of damage and improving corrosion resistance, while eliminating the need for additional sealing or painting.

Implementation Method 1

The pressure of the gas jet is in the range of 50 to 100 bar, and the metal coating has an adhesion strength of 50 MPa

Methodology Applied
Scientific EffectKinetic energy:

Implementation Method 2

the metal coating of the metallic rolling bearing component proposed here is applied directly to the non-sandblasted surface using a high-pressure cold spray process

Methodology Applied
Scientific EffectCold spray process:

Data Source

PatentEP3647615B1Metallic rolling bearing component
Publication Date: 2024.06.19 AB SKF SKF PATENT DEPARTMENT
  • EP3647615B1 patent drawingFigure 1

AI summary

A metallic rolling or sliding bearing component (2, 4) is disclosed having at least one non-sandblasted surface and having at least one partial metal coating, wherein the metal coating is applied directly to the non-sandblasted surface by means of a cold-spray process.