Conductive Seal Structure for Stable Grounding and Noise Reduction

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Solution Overview

Problem

Conventional electromagnetic noise reduction devices in electrified vehicles experience degradation in electrical conductivity performance over time, failing to effectively dissipate noise to the housing.

Innovation Solution

A sealing apparatus with conductive grease housed between an outer and inner seal part, featuring conductive elastic bodies with protrusions and a conduction lip with a wedge-shaped cross-section, and a spring to maintain contact and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional electromagnetic noise reduction devices are used, then space is saved, but electrical conductivity performance degrades over time

Engineering Contradiction:
ImprovespaceVSAvoidelectrical conductivity performance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent introduces conductive grease as an intermediary substance between the inner and outer elastic body parts. This grease fills the space between components and maintains electrical conductivity through its conductive properties, preventing the degradation that occurs in conventional direct-contact designs while preserving compact dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical state and material properties of the conductive path by using conductive grease instead of solid conductive materials. This parameter change allows the system to maintain low electrical resistance over time while keeping the device compact, as the grease can flow and adapt to maintain optimal contact.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If metallic brush is used for grounding, then electrical conductivity is achieved, but metallic powder is generated causing safety issues

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmetallic powder
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical sliding contact system (metallic brush) with an elastic body system that uses elastic deformation for contact. This substitution eliminates the generation of metallic powder while maintaining electrical conductivity, as the elastic bodies deform rather than wear down like metallic brushes.

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

Solution Approach 2:

The patent uses composite elastic body parts that combine elastic material with conductive properties. These composite materials provide both the mechanical flexibility needed for reliable contact and the electrical conductivity required for grounding, without the harmful byproducts of metallic brush systems.

Inventive Principle:
Principle #40Composite materials

3Reliability

If sliding movement occurs between shaft and metallic brush, then grounding is achieved, but metallic powder flies requiring additional safety components

Engineering Contradiction:
ImprovegroundingVSAvoidcover for flying prevention
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the sliding mechanical contact of metallic brushes with elastic bodies that make stationary contact through elastic deformation. This eliminates the sliding movement that generates flying metallic powder, removing the need for additional protective covers and simplifying the overall device structure.

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

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 apparatus maintains stable electrical conductivity and noise reduction by forming a low-resistance conductive path, preventing noise generation and degradation even after long-term use.

Implementation Method 1

conductive grease is housed in the space formed by the outer seal part and the inner seal part

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

an inner elastic body part and an outer elastic body part which are formed of an elastic body having electrical conductivity

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

a spring to maintain contact and conductivity

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP3828446B1Sealing device
Publication Date: 2024.05.22 NOK CORP
  • EP3828446B1 patent drawingFigure 1
  • EP3828446B1 patent drawingFigure 2
  • EP3828446B1 patent drawingFigure 3

AI summary

Provided is a sealing apparatus capable of inhibiting a degradation in electrical conductivity performance. A sealing apparatus includes an outer seal part and an inner seal part, and conductive grease housed in a space . An outer elastic body part of the outer seal part is formed from an elastic body having electrical conductivity and includes a dust lip, a conduction lip , and a gasket part. At an annular fitting surface, the inner seal part is attached to the outer seal part. An inner elastic body part of the inner seal part is formed from an elastic body having electrical conductivity and includes a grease lip. The outer seal part has a spring that is put on an outer periphery side of the conduction lip to press the conduction lip against an inner peripheral member.