Electric Compressor Terminal Sealing Against Refrigerant Ingress

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Solution Overview

Problem

The existing sealing structure of electric compressors in new energy vehicles is inadequate, leading to attenuation of insulation performance and safety risks due to gaps between the motor sheath and sealing plugs, allowing refrigerant to contact motor terminals and potentially causing short circuits.

Innovation Solution

A sealing structure comprising an upper sealing plug, lower sealing plugs, and a motor sheath that encloses accommodation spaces, with post-through holes and threading holes to prevent refrigerant ingress, and made from different materials like Polyamide56 for enhanced ductility and insulation, ensuring a secure connection between terminals and motor terminals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single sealing plug is used to seal the connection between terminals and motor sheath, then the structure is simple, but the sealing performance is insufficient and gaps remain allowing refrigerant contact

Engineering Contradiction:
Improvesealing performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single sealing plug is divided into an upper sealing plug and a lower sealing plug, with the upper sealing plug sealing the upper end of the motor sheath and the lower sealing plug sealing the lower end. This segmentation ensures complete sealing of the motor sheath interior space, preventing refrigerant from contacting the terminals and motor terminals, thereby resolving the contradiction between simple structure and sufficient sealing performance.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the motor sheath end is left open for connection access, then the installation is easier, but refrigerant can enter and contact electrical components causing insulation degradation

Engineering Contradiction:
Improveinsulation performanceVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The upper sealing plug is inserted into the upper end of the motor sheath, and the lower sealing plug is inserted into the lower end of the motor sheath, creating a nested sealing structure. This nested design completely encloses the motor sheath interior space, preventing refrigerant ingress while maintaining installation ease through the through-holes in the sealing plugs that allow wire passage.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If sealing plugs completely enclose the motor sheath interior space, then insulation performance is improved, but the structure becomes more complex and harder to assemble

Engineering Contradiction:
Improveinsulation performanceVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The upper sealing plug and lower sealing plug are designed with pre-formed through-holes for terminal wires and threading holes for three-phase wires, respectively. This preliminary action during manufacturing allows for easy assembly by simply inserting the wires through the pre-formed holes, eliminating the need for complex post-assembly operations while maintaining complete sealing and insulation performance.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4310330A1Sealing structure of electric compressor, electric compressor and vehicle
Publication Date: 2024.01.24 MAHLE INT GMBH
  • EP4310330A1 patent drawingFigure 1~2
  • EP4310330A1 patent drawingFigure 3~4
  • EP4310330A1 patent drawingFigure 5

AI summary

Sealing structure of an electric compressor comprising an upper sealing plug (100), lower sealing plugs (200), a sheath (300) and motor terminals (400) as well as three-phase wires (700) of the motor of the electric compressor and terminals of the inverter (500) that are inserted into the sealing structure. One end of the upper sealing plug is connected to the sheath, the lower sealing plugs are at least partially inserted into the sheath, the lower sealing plugs and the sheath enclose accommodation spaces, the motor terminals are arranged in the accommodation spaces, and are connected to the motor of the electric compressor through the three-phase wires of the motor. The terminals of the inverter are inserted into the motor terminals by passing through the upper sealing plug. Compressor comprising such a sealing structure and vehicle comprising such a compressor.