Electric Compressor Housing Seal Layout for Larger Inverter Volume

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Solution Overview

Problem

Existing electric compressors face design flexibility limitations due to the need for machining grooves on the outer circumferential surface of the inverter case, which can interfere with other structures, preventing expansion and increasing the overall size and axial length.

Innovation Solution

The electric compressor design includes a first connection part with grooves for O-rings on the inner surface, allowing the second connection part to seal without requiring machining on its outer surface, enabling expansion in the radial direction and increasing the inverter housing volume without increasing the axial length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hermetic compressor with an integrated motor and compressor is used, then reliability is improved by eliminating leaks, but manufacturing precision and assembly complexity increase due to the integrated design

Engineering Contradiction:
Improveleak preventionVSAvoidintegrated structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The motor and compressor are integrated into a single hermetic unit where the motor drives the compressor directly through a shared shaft. The motor housing and compressor housing are merged into one sealed structure, eliminating external connections and potential leak points while maintaining functional independence of both components.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the motor and compressor are integrated in a hermetic design, then reliability improves, but ease of repair deteriorates because the entire unit must be replaced

Engineering Contradiction:
Improvesealed systemVSAvoidcomponent replacement
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The hermetic compressor is divided into functionally independent modules: the motor assembly and the compressor assembly. Each module can be independently manufactured, tested, and replaced. The motor housing and compressor housing are separated by a defined interface that allows for modular replacement without replacing the entire unit.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the motor housing and compressor housing are separated, then ease of manufacture improves, but reliability decreases due to potential leaks at the connection interface

Engineering Contradiction:
Improvehousing fabricationVSAvoidconnection seal
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A flange connection serves as an intermediary element between the motor housing and compressor housing. This flange includes integrated sealing surfaces and sealing elements (such as gaskets or O-rings) that create a leak-proof connection while allowing the housings to be manufactured separately and assembled through standardized joining processes.

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

This configuration enhances design flexibility by allowing for a larger inverter housing volume and easier installation, reduces refrigerant leakage, and improves refrigerant flow efficiency while minimizing corrosion and pressure loss.

Implementation Method 1

an electric motor which is arranged to be driven by a single phase electric supply

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a compressor which is arranged to compress the refrigerant

Methodology Applied
Scientific EffectMechanical compression: Compression

Data Source

PatentEP4365449B1Electric compressor
Publication Date: 2026.04.15 MITSUBISHI HEAVY IND THERMAL SYST
  • EP4365449B1 patent drawingFigure 1
  • EP4365449B1 patent drawingFigure 2
  • EP4365449B1 patent drawingFigure 3

AI summary

An object is to improve design flexibility. An electric compressor (1) includes: a motor (17) configured to drive a scroll compression mechanism (7) that compresses a refrigerant; an inverter configured to drive the motor (17); a housing (2) filled with the refrigerant and accommodating the motor (17); and a lower case (40) connected to the housing (2), which is aligned with the lower case (40) in the axial direction, and accommodating the inverter. The housing (2) has a cylindrical first connection part (51) centered on the center axis (C) extending in the axis direction. The lower case (40) has a cylindrical second connection part (55) centered on the center axis (C) extending in the axial direction. The outer circumferential surface of the first connection part (51) and the inner circumferential surface of the second connection part (55) are in contact with each other.