Arc-Shaped Lip Packing for Shock Absorber Sealing

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Solution Overview

Problem

Existing gas spring shock absorbers experience increased friction during compression and extension operations due to air leakage and movement of compression ratio adjustment oil between chambers, leading to unstable reaction force characteristics.

Innovation Solution

The design incorporates arc-shaped lip packings with specific radial dimensions to enhance sealing performance, preventing gas and oil leakage between chambers, thereby reducing friction and stabilizing reaction force characteristics during both compression and extension operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If edge-shaped lip packings are used to prevent air leakage and oil movement between chambers, then sealing performance is improved, but friction increases and reaction force characteristics become unstable

Engineering Contradiction:
Improvesealing performanceVSAvoidfriction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies curvature by changing the lip packing edge shape from angular (edge-shaped) to rounded (arc-shaped). The arc-shaped lip packing has a rounded contact surface that reduces stress concentration and minimizes friction with the sealing surface, while still maintaining effective sealing. This curvature modification directly addresses the contradiction by reducing friction and stabilizing reaction force characteristics while preserving sealing performance.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If arc-shaped lip packings are used to reduce friction, then operation smoothness is improved, but sealing effectiveness may deteriorate

Engineering Contradiction:
Improveoperation smoothnessVSAvoidsealing effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies parameter changes by optimizing the arc radius of the arc-shaped lip packing. The arc radius is specifically designed to be within a certain range to balance sealing effectiveness and friction reduction. This parameter optimization ensures that the rounded contact surface maintains adequate contact pressure for effective sealing while minimizing friction and ensuring smooth operation.

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 use of arc-shaped lip packings effectively minimizes friction and maintains stable reaction force characteristics by preventing oil film shortage and leakage, ensuring smooth operation and consistent performance in gas spring shock absorbers.

Implementation Method 1

volumes of the inner chamber and the outer chamber are reduced, gas in the inner chamber and the outer chamber is compressed, and thus a gas spring is formed to generate a reaction force

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 2

a surface of the lip in contact with an outer circumferential surface of the rod is formed in an arc shape

Methodology Applied
Scientific EffectSealing contact: Friction

Data Source

PatentEP3073145B1Shock absorber
Publication Date: 2018.04.18 SHOWA CORP
  • EP3073145B1 patent drawingFigure 1
  • EP3073145B1 patent drawingFigure 2
  • EP3073145B1 patent drawingFigure 3~4

AI summary

Disclosed is a shock absorber that includes first to third gas spring chambers, and performs a compression operation and an extension operation. The shock absorber includes a lip packing which works as a rod lip packing for the third gas spring chamber and has an arc-shaped lip, a lip packing which works as a piston lip packing for the third gas spring chamber and has the arc-shaped lip, a lip packing which works as a piston lip packing for the first gas spring chamber and has an edge-shaped lip, and a lip packing which works as a rod lip packing for the second gas spring chamber and has the edge shaped lip.