Conductive Seal Lip Assembly for Shaft Noise and Erosion Control

Solution Overview

Problem

Existing sealing devices in vehicles with electric motors face challenges in easily imparting conductivity to address electromagnetic noise and electrical erosion, often requiring design changes to incorporate conductive brushes or materials, which is inefficient.

Innovation Solution

A conductive sliding member with an annular conductive lip portion and sealing device bonding portions that can be easily attached to a sealing device main body, forming a conductive path between a rotating shaft and housing, thereby reducing electromagnetic noise and electrical erosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductive brush is incorporated into a reduction gear or the sealing device is replaced with a conductive material sealing device, then conductivity is improved to address electromagnetic noise and electrical erosion, but design changes of the reduction gear are required which increases device complexity and manufacturing difficulty

Engineering Contradiction:

ImproveconductivityVSAvoiddesign changes

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sealing device is divided into a non-conductive sealing device main body portion and a separate conductive sliding member. This segmentation allows the conductive function to be added without changing the design of the main sealing body, thus improving conductivity while avoiding increased device complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive sliding member serves multiple functions: it provides conductivity to address electromagnetic noise and electrical erosion, and it also acts as a sealing element by sliding on the shaft surface. This multi-functionality eliminates the need for separate conductive brushes or design changes to the reduction gear.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a conductive brush is incorporated into a reduction gear or the sealing device is replaced with a conductive material sealing device, then conductivity is improved to address electromagnetic noise and electrical erosion, but manufacturing complexity increases due to additional incorporation steps

Engineering Contradiction:

ImproveconductivityVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing device is divided into a non-conductive sealing device main body portion and a separate conductive sliding member. This segmentation allows the conductive function to be added without changing the design of the main sealing body, thus improving conductivity while avoiding increased device complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive sliding member is designed with predetermined bonding portions that facilitate easy attachment to the sealing device main body portion. This preliminary design of bonding interfaces simplifies the manufacturing process by providing clear assembly guidelines and reducing the complexity of incorporating the conductive element.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the sealing device is replaced with a conductive material sealing device, then conductivity is improved, but the sealing device design must be changed which reduces adaptability to existing systems

Engineering Contradiction:

ImproveconductivityVSAvoiddesign compatibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sealing device is divided into a non-conductive sealing device main body portion and a separate conductive sliding member. This segmentation allows the conductive function to be added without changing the design of the main sealing body, thus improving conductivity while avoiding increased device complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive sliding member acts as an intermediary element between the non-conductive sealing device main body portion and the shaft. It provides the necessary conductivity function while allowing the original sealing device design to remain unchanged, thus maintaining adaptability to existing systems.

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

The solution allows for easy conductivity enhancement without altering the sealing device design, reducing noise and erosion while maintaining sealing performance, and simplifying assembly and attachment processes.

Implementation Method 1

a conductive sliding member attached to an annular space between a relatively rotating shaft and a housing having conductivity

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

an annular conductive lip portion that is formed of a molded body of an elastic body having conductivity, and is slidable on a surface of the shaft

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20260078825A1Conductive sliding member, sealing device, and manufacturing method of sealing device

Publication Date: 2026.03.19 NOK CORP

AI summary

A conductive sliding member includes, in an annular space between a relatively rotating shaft and a housing having conductivity, an annular conductive lip portion that is formed of a molded body of an elastic body having conductivity, and is slidable on a surface of the shaft; and a sealing device bonding portion that is provided on an outer peripheral side of the conductive lip portion and is capable of being bonded to a sealing device main body portion on a side opposite to a sealing target fluid side of a sealing device that seals the annular space.