Electric Compressor Terminal Insulation via Elastic Tube

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Solution Overview

Problem

Existing electric compressors face challenges in ensuring effective electrical insulation between the insulating member and the cluster block due to tolerances and planarity issues in sealing configurations, leading to potential short-circuiting risks.

Innovation Solution

The implementation of an elastic and electrically-insulating annular insulating tube covering the terminal pin, with low-rigidity portions at both axial ends, sandwiched between the cluster block and insulating member, to enhance sealing and insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If annular sealing members are used with radial sealing configuration, then sealing properties are improved, but it becomes difficult to ensure electrical insulation due to tolerance balance issues between inner and outer circumferential surfaces

Engineering Contradiction:
Improvesealing propertiesVSAvoidelectrical insulation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing structure is divided into two independent sealing members: a first annular sealing member for radial sealing between the insulator and terminal pin, and a second annular sealing member for axial sealing between the terminal pin and cluster block. This segmentation allows each sealing member to independently perform its sealing function without interfering with the electrical insulation requirements of the other, thereby resolving the contradiction between sealing properties and manufacturing precision for electrical insulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The terminal pin serves as an intermediary element that bridges the gap between the insulator and cluster block. By positioning the terminal pin as a separate conductive component with dedicated sealing members, the structure provides a clear electrical pathway while maintaining insulation between the insulator and cluster block through the sealing members, thus resolving the electrical insulation issue.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If cylindrical rubber rings are sandwiched between glass terminal plate and terminal case with axial sealing, then sealing is achieved, but sealing properties are affected by large tolerance of axial separation distance

Engineering Contradiction:
ImprovesealingVSAvoidaxial separation distance tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing configuration changes from axial sealing to radial sealing by repositioning the sealing members. The first annular sealing member is positioned on the radial outer circumferential surface of the terminal pin, creating a radial seal that is independent of axial separation distance tolerances. This parameter change in sealing direction eliminates the sensitivity to axial distance variations.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If contact area of sealing faces is used to ensure insulating distance, then insulation is provided, but contact area becomes narrower if sealing faces have poor planarity and parallelism

Engineering Contradiction:
Improveinsulating distanceVSAvoidcontact area
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The sealing approach transitions from relying on face-to-face contact in one dimension (axial direction) to radial sealing in another dimension. The first annular sealing member seals radially between the insulator and terminal pin, creating a sealing interface that is not dependent on the planarity and parallelism of axial sealing faces, thereby maintaining both insulation and reliable contact area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Improves electrical insulation and sealing properties by accommodating dimensional tolerances, ensuring stable contact faces and reducing the risk of short-circuiting.

Implementation Method 1

an elastic and electrically-insulating annular insulating tube covering the terminal pin

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

electrically-insulating annular insulating tube

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 3

low-rigidity portions at both axial ends... of lower rigidity than a central portion... to accommodate dimensional tolerances

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP4600492A1Electric compressor
Publication Date: 2025.08.13 VALEO ELECTRIFICATION
  • EP4600492A1 patent drawingFigure 1
  • EP4600492A1 patent drawingFigure 2
  • EP4600492A1 patent drawingFigure 3

AI summary

The present invention addresses the problem of improving electric insulation performance between an insulation member and a cluster block. An electric compressor (10) is provided with a sealed terminal (130). The sealed terminal (130) is provided with a terminal plate (131) fixed to a housing (20), a terminal pin (132) that is inserted into a penetration hole (131a) of the terminal plate (131) and electrically connects a connection terminal (106) to the outside of the housing (20), and an insulation member (140) that seals and insulates between the terminal plate (131) and the terminal pin (132). The terminal pin (132) is liquid-tightly covered with an annular insulation tube (150) having elasticity and electric insulation performance. The insulation tube (150) has low rigidity parts (160, 160) having rigidity lower than that of a central part (470) at both ends thereof in an axial direction, and is held between the cluster block (110) and the insulation member (140).