Electric Scroll Compressor Passive Pressure Recirculation for Noise Control

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Solution Overview

Problem

Electric compressors in battery-powered vehicles face challenges with high-speed operation leading to noise and reduced battery life due to continuous electrical energy consumption, and heat management issues limiting heat pump efficiency.

Innovation Solution

A scroll-type electric compressor with a passive pressure system that automatically recycles compressed refrigerant from the discharge volume to the intake volume in response to pressure differentials, enhancing efficiency and reducing noise by allowing recompression and heat extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the electric compressor operates at high speed to improve cooling efficiency, then the cooling performance is improved, but noise increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The passive pressure system operates periodically by automatically opening and closing the passage between discharge and intake volumes based on pressure differentials. This periodic operation allows the compressor to recycle compressed refrigerant at specific cycles, reducing continuous high-speed operation noise while maintaining cooling efficiency through timed refrigerant recirculation

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If the electric compressor runs continuously to provide heating or cooling, then the thermal management function is improved, but battery life is reduced

Engineering Contradiction:
Improvethermal management functionVSAvoidbattery life
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The passive pressure system provides self-service by automatically recycling compressed refrigerant from the discharge volume to the intake volume based on pressure differentials. This self-regulating mechanism enables the compressor to maintain thermal management functions more efficiently, reducing continuous operation requirements and thereby extending battery life without compromising heating or cooling capabilities

Inventive Principle:
Principle #25Self-service

3Power

If the electric compressor operates as a heat pump to move heat, then the heat pump efficiency is improved, but the saturation temperature of the refrigerant limits the efficiency

Engineering Contradiction:
Improveheat pump efficiencyVSAvoidsaturation temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The passive pressure system performs preliminary action by recycling compressed refrigerant back to the intake volume before it would normally be discharged. This pre-recirculation allows the refrigerant to undergo additional compression cycles, effectively bypassing the saturation temperature limitation and enabling the heat pump to operate at higher efficiencies by maintaining the refrigerant in a sub-saturated state

Inventive Principle:
Principle #10Preliminary action

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 passive pressure system improves compressor efficiency, reduces noise, and extends battery life by optimizing refrigerant flow and heat management, particularly in electric vehicles.

Implementation Method 1

The passive pressure system is configured to automatically open a passage between the discharge volume and the intake volume allowing compressed refrigerant to be recycled into the intake volume

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4607030A1Electric compressor with passive pressure system between high and low pressure regions
Publication Date: 2025.08.27 MAHLE INT GMBH
  • EP4607030A1 patent drawingFigure 1
  • EP4607030A1 patent drawingFigure 2
  • EP4607030A1 patent drawingFigure 3

AI summary

An electric compressor (10) includes a housing (12), refrigerant inlet port (68), a refrigerant outlet port (70), an inverter section (44), a motor section (54), a compression device (18), and a passive pressure system (150). The refrigerant inlet port is coupled to the housing and is configured to introduce the refrigerant to the intake volume (74). The compression device is a scroll-type compression device configured to compress the refrigerant. The refrigerant outlet port is coupled to the housing and is configured to allow compressed refrigerant to exit the scroll-type electric compressor from the discharge volume (82). The passive pressure system is located within the compression device and has a first end located adjacent the intake volume (74) and a second end located adjacent the discharge volume (82). The passive pressure system is configured to automatically open a passage between the discharge volume (82) and the intake volume (74) allowing compressed refrigerant to be recycled into the intake volume.