Suction Valve Assembly for Compressor Reverse Oil Flow Blocking

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Solution Overview

Problem

Conventional compressors face issues with reverse flow of refrigerant and oil into the accumulator during compressor shutdown, leading to oil deficiency and performance deterioration, and existing reverse flow prevention valves are difficult to install and maintain, with coil spring-based valves prone to malfunction.

Innovation Solution

A suction valve assembly that uses a lifting/lowering valve guided by a protruding pipe, moving based on pressure difference and weight, to quickly close the connection between the refrigerant suction pipe and accumulator, preventing reverse oil flow and allowing easy maintenance, with a design that minimizes refrigerant loss and optimizes compressor performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reverse flow prevention valves are installed on the refrigerant discharge side of the suction pipe or in the accumulator, then reverse flow can be prevented, but installation and maintenance become difficult

Engineering Contradiction:
Improvereverse flow preventionVSAvoidvalve installation and maintenance
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The suction valves are integrated directly into the suction pipe structure itself, forming an integrated assembly. The first suction valve is built into the compression chamber, and the second suction valve is built into the suction pipe. This merging of the valve function with the pipe structure eliminates the need for separate, complex valve installations and simplifies maintenance, as the valves become inherent parts of the suction system rather than add-on components.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If a coil spring is used to provide restoring force for the suction valve, then the valve can open and close automatically, but the coil spring may undergo torsion leading to malfunction or damage

Engineering Contradiction:
Improveautomatic valve operationVSAvoidvalve durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coil spring-based mechanical restoring force system is replaced with a weight-based gravitational restoring force system. Instead of using a coil spring that undergoes torsion and elastic deformation, a weight is suspended to provide a constant downward gravitational force. This substitution eliminates the torsional stress and cyclic loading that cause coil spring fatigue and failure, while still providing reliable automatic valve operation through the gravitational force acting on the weight.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Effectively prevents reverse flow of oil and refrigerant, maintains compressor performance by minimizing oil loss and simplifying maintenance, and avoids the limitations of coil spring-based systems.

Implementation Method 1

moving based on pressure difference and weight, to quickly close the connection between the refrigerant suction pipe and accumulator

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

moving based on pressure difference and weight, to quickly close the connection between the refrigerant suction pipe and accumulator

Methodology Applied
Scientific EffectWeight: Gravitation

Data Source

PatentEP3757391B1Suction valve assembly of compressor
Publication Date: 2023.12.20 LG ELECTRONICS INC
  • EP3757391B1 patent drawingFigure 1
  • EP3757391B1 patent drawingFigure 2
  • EP3757391B1 patent drawingFigure 3~4

AI summary

A suction valve assembly of a compressor of the present invention includes a body part connecting a compression chamber of the compressor with an accumulator, and a lifting/lowering valve provided in the body part, wherein the lifting/lowering valve is moved upward by pressure difference between an inner part of the accumulator and an inner part of the compression chamber when operation of the compressor stops and blocks reverse flow of oil to the accumulator. Accordingly, when the operation of the compressor stops, compressed oil is prevented from reversely flowing to the accumulator.