Compressor Discharge Pipe Communication Holes for Oil Separation

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Solution Overview

Problem

Existing compressors face issues with oil backflow and overflow through the refrigerant discharge pipe, leading to increased manufacturing costs and reduced efficiency due to the need for additional oil separation devices and enlarged clearances, which affect motor performance.

Innovation Solution

A scroll compressor design with a refrigerant discharge pipe featuring communication holes and a specific insertion depth, allowing for efficient oil separation without additional oil separators, maintaining motor efficiency and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the refrigerant discharge pipe is extended toward the driving motor to increase oil separation effect, then oil separation efficiency is improved, but oil backflow or overflow occurs due to stagnant oil in the small space between the discharge pipe and driving motor

Engineering Contradiction:
Improveoil separation efficiencyVSAvoidoil backflow or overflow
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The refrigerant discharge pipe is divided into multiple sections with communication holes at different heights. The first communication hole is positioned in an upper section and the second communication hole in a lower section, allowing the pipe to interact with oil at multiple levels and preventing backflow/overflow by providing multiple escape paths for trapped oil

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Communication holes are selectively positioned at specific heights along the refrigerant discharge pipe to create localized ventilation zones. The first communication hole is located in an upper section while the second is in a lower section, allowing different regions of the pipe to serve different functions in preventing oil backflow

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If clearance between the casing and driving motor is enlarged to suppress oil stagnation, then oil backflow is reduced, but motor efficiency deteriorates due to reduced flux path area

Engineering Contradiction:
Improveoil backflowVSAvoidmotor efficiency
Core Design Contradiction:
Object-generated harmful factorsVSPower

Solution Approach 1:

The refrigerant discharge pipe acts as an intermediary structure that provides a controlled path for oil management. By incorporating communication holes at specific heights, the pipe mediates between the need for close clearance to maintain motor performance and the need to prevent oil backflow, eliminating the need to enlarge clearance

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a separate oil separation device is installed inside the casing, then oil separation effect is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveoil separation effectVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The refrigerant discharge pipe is designed to perform multiple functions: it discharges refrigerant, separates oil through its extended position and communication holes, and prevents oil backflow. This multi-functional design eliminates the need for separate oil separation devices, reducing part count and manufacturing complexity while maintaining effective oil separation

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4279743B1compressor
Publication Date: 2025.08.20 LG ELECTRONICS INC
  • EP4279743B1 patent drawingFigure 1
  • EP4279743B1 patent drawingFigure 2
  • EP4279743B1 patent drawingFigure 3

AI summary

The present disclosure relates to is a compressor. The compressor may be provided with a communication hole (1161) between an inlet (116a) and an outlet (116b) of a refrigerant discharge pipe (116) coupled through an upper surface of a casing (110), the communication hole penetrating between an outer circumferential surface and an inner circumferential surface of the refrigerant discharge pipe. Thus, during oil sealing through the refrigerant discharge pipe, a flux path area of a driving motor (120) may be ensured, and a number of winding wires and/or a coil diameter of a stator coil may be ensured. Thus, efficiency of the driving motor may be maintained and backflow or overflow of oil through the refrigerant discharge pipe may be suppressed. In addition, during operation of the compressor, oil may be suppressed from being excessively leaked through the refrigerant discharge pipe without having to include a separate oil separator inside or inside the casing.