Bus Bar Wiring Assembly With Elastomer Sealing Against Leakage Current

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The occurrence of leakage currents due to gaps formed between bus bars and housings made of materials with different linear expansion coefficients, which can lead to water ingress and short-circuits, is a challenge in electrical equipment with high-voltage and low-voltage bus bars.

Innovation Solution

A wiring component design that includes bus bars embedded in a resin housing with elastomer-filled hollow portions covering the intermediate portions, a lid member to seal the opening, and a lid portion embedded in the elastomer to prevent gaps and water ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulating resin is filled between bus bars to prevent leakage current, then electrical insulation is improved, but gaps form due to thermal expansion differences causing water ingress

Engineering Contradiction:

Improveprevention of leakage currentVSAvoidwater ingress through gaps

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a composite sealing structure combining resin material and elastomer material. The resin housing provides structural support and electrical insulation, while the elastomer material provides flexible sealing that accommodates thermal expansion differences. This composite approach allows both materials to perform their optimal functions without creating gaps that would allow water ingress.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the physical state and properties of the sealing material by introducing elastomer material with different thermal expansion characteristics. The elastomer's ability to deform and maintain contact under varying temperature conditions prevents gap formation while maintaining the electrical insulation properties of the resin filling.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If bus bars are exposed at both ends for connection, then ease of connection is improved, but gaps at boundaries allow water to advance causing leakage current

Engineering Contradiction:

Improveconnection of bus barsVSAvoidprevention of leakage current

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent employs elastomer material as a flexible sealing shell that conforms to the bus bar geometry and housing boundaries. This flexible sealing layer maintains contact and prevents water ingress while allowing the bus bars to be exposed at their ends for electrical connections. The elastomer's flexibility accommodates dimensional changes without compromising the seal.

Inventive Principle:

Principle #30Flexible shells and thin films

3Strength

If resin housing is used to embed bus bars, then structural integrity is improved, but thermal expansion mismatch creates gaps

Engineering Contradiction:

Improvestructural integrity of housingVSAvoidgap formation due to thermal expansion

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The patent creates a composite sealing system where the rigid resin housing provides structural integrity while the flexible elastomer material compensates for thermal expansion mismatch. The elastomer layer absorbs dimensional changes through elastic deformation, preventing gap formation between the resin housing and bus bars while maintaining the overall structural strength of the assembly.

Inventive Principle:

Principle #40Composite materials

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 design effectively prevents leakage currents by ensuring the elastomer follows thermal expansion, sealing gaps, and maintaining a reliable electrical connection despite temperature changes.

Implementation Method 1

since the metal bus bar and the filled resin have different linear expansion coefficients, a minute gap may be generated due to displacement caused by a temperature change

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a filling material made of an elastomer filled in the hollow portion and covering an entire periphery of the bus bars at least at a boundary portion between the intermediate portions and the housing

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12609517B2Wiring component for electrical equipment

Publication Date: 2026.04.21 MITSUBISHI ELECTRIC CORP

AI summary

A wiring component for electrical equipment comprises a plurality of bus bars, a housing made of resin in which the plurality of bus bars are each exposed at both ends and embedded inside at an interval to each other, and a hollow portion is provided in which an opening through which an intermediate portion of each of the plurality of bus bars is exposed is formed, a filling material made of an elastomer filled in the hollow portion and covering an entire periphery of the bus bars at least at a boundary portion between the intermediate portions and the housing, and a lid member including a lid portion that closes the opening and an embedded portion that extends from the lid portion toward the filling material and is embedded in the filling material.