Shock Absorber Piston Sealing With Localized Lubrication

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Solution Overview

Problem

The existing shock absorbers for vehicles, particularly those with an oilless gas chamber and piston, face challenges in enhancing steering stability and riding comfort due to the lack of lubrication, leading to increased wear and reduced seal effectiveness.

Innovation Solution

Incorporating lubricating members on the piston that apply a lubricating film to the cylinder's inner surface, allowing the sealing lips to slide smoothly, thereby improving durability and sealability, even in an oilless configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the shock absorber uses an oilless gas chamber and piston structure, then the weight and maintenance complexity are reduced, but the steering stability and riding comfort deteriorate due to increased wear and reduced seal effectiveness

Engineering Contradiction:
Improvemaintenance complexityVSAvoidsteering stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by providing lubricating members only at specific locations where sealing lips contact the cylinder, rather than filling the entire gas chamber with oil. This localized lubrication approach reduces overall device complexity and maintenance needs while maintaining reliability at critical sealing points.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The lubricating members act as intermediaries between the sealing lips and the cylinder surface. These members contain lubricant that reduces friction and wear at the sealing interface, thereby maintaining steering stability and riding comfort without requiring a fully oil-filled system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Weight of moving object

If the shock absorber uses an oilless gas chamber and piston structure, then the weight is reduced, but the steering stability and riding comfort deteriorate due to increased wear

Engineering Contradiction:
ImproveweightVSAvoidsteering stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent implements local quality by placing lubricating members only at the sealing lip contact areas on the piston, rather than using oil throughout the entire gas chamber. This minimizes the weight of lubricant while ensuring reliability at the critical sealing interfaces that affect steering stability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The lubricating members serve as intermediaries that provide necessary lubrication at the sealing surfaces without requiring the shock absorber to be filled with oil. This mediator approach reduces overall weight while maintaining the steering stability and riding comfort needed for reliable operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the sealing lip slides directly on the cylinder surface without lubrication, then the structure is simpler, but the durability and seal effectiveness deteriorate due to increased wear

Engineering Contradiction:
Improvestructure complexityVSAvoiddurability
Core Design Contradiction:
Device complexityVSDuration of action of stationary object

Solution Approach 1:

The patent applies local quality by adding lubricating members only at the specific locations where sealing lips contact the cylinder, rather than implementing a complete oil-filled system. This localized approach maintains structural simplicity while significantly improving durability through reduced wear at the sealing interfaces.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The lubricating members act as intermediaries between the sealing lips and cylinder surface, containing lubricant that reduces friction and wear. This intermediary layer protects the sealing surfaces, extending the duration of action of the stationary cylinder and improving overall durability without complicating the overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If the sealing lip slides directly on the cylinder surface without lubrication, then the manufacturing is simpler, but the seal effectiveness deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidseal effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent implements local quality by incorporating lubricating members only at the sealing lip contact areas on the piston, rather than requiring a fully oil-filled chamber. This approach maintains ease of manufacture compared to complete oil systems while improving seal effectiveness through reduced wear and better sealing lip contact.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The lubricating members serve as intermediaries that contain lubricant at the sealing interface, reducing friction and improving seal effectiveness. This intermediary approach maintains manufacturing simplicity while ensuring reliable sealing performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enhances the operational performance of the shock absorber, leading to improved steering stability and riding comfort by ensuring smooth piston movement and maintaining the air spring's function, while also reducing the weight and maintenance complexity of the shock absorber.

Implementation Method 1

a first lubricating member, which is provided on a side closest to the gas chamber in an outer peripheral surface of the piston so as to be capable of sliding contact with an inner peripheral surface of the cylinder, and which contains a lubricant

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

each sealing lip slides on the lubricating film

Methodology Applied
Scientific EffectBoundary lubrication: Lubrication

Data Source

PatentEP3822509B1Shock absorber
Publication Date: 2024.11.13 ASTEMO LTD
  • EP3822509B1 patent drawingFigure 1
  • EP3822509B1 patent drawingFigure 2
  • EP3822509B1 patent drawingFigure 3

AI summary

A shock absorber (100) includes an outer tube (101), an inner tube (102) fitted to the outer tube (101) so as to be able to move forward and backward, a cylinder (103) provided inside the outer tube (101) and extending inside the inner tube (102), a rod (104) extending from an end portion of the inner tube (102) exposed from the outer tube (101) to an inside of the cylinder (103), and a piston (105) which is provided on the rod (104) and divides the inside of the cylinder (103) to form a gas chamber(131). On an outer peripheral surface (105b) of the piston (105), a first lubricating member (151), a first seal member (152), and a second seal member (153) are provided in this order from a side closest to the gas chamber (131) to a side away from the gas chamber (131). The members (151, 152, 153) are in sliding contact with an inner peripheral surface (103a) of the cylinder (103).