Scroll Compressor Suction Check Valve Design to Reduce Pressure Loss

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Solution Overview

Problem

Suction pressure loss occurs in scroll compressors due to a reduction in passage area caused by cylindrical wall portions of the valve body and support, leading to inefficiencies.

Innovation Solution

The design allows one circumferential wall of the valve body or valve seat to have a smaller outside diameter than the other, enabling it to be housed inside, thereby increasing the passage area and reducing suction pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If cylindrical wall portions of the valve body and support are made to have substantially the same size, then structural stability is improved, but suction passage area is reduced causing suction pressure loss

Engineering Contradiction:
Improvestructural stabilityVSAvoidsuction passage area
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent applies nesting by making one circumferential wall (either the first circumferential wall of the valve body or the second circumferential wall of the valve seat) have a smaller outside diameter than the inside diameter of the other circumferential wall. This allows one circumferential wall to be housed inside the other, creating a nested configuration that increases the suction passage area while maintaining structural stability through the interlocked design.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Loss of energy

If the passage area of suction passage is increased, then suction pressure loss is reduced, but structural support is weakened

Engineering Contradiction:
Improvesuction pressure lossVSAvoidstructural support
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The nested configuration of circumferential walls increases the suction passage area, allowing greater refrigerant flow and reduced suction pressure loss while the interlocking nature of the nested walls provides structural support.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent employs asymmetry by making one circumferential wall have a smaller outside diameter than the inside diameter of the other circumferential wall. This asymmetric design allows the walls to nest within each other, optimizing both the passage area for reduced pressure loss and providing structural support through the asymmetric interlocking configuration.

Inventive Principle:
Principle #4Asymmetry

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 reduces suction pressure loss and improves the volume efficiency of the compressor, particularly when using intermediate/low pressure refrigerants like R513A or R1234yf.

Implementation Method 1

a compression spring arranged between the valve body and the valve seat and configured to bias the valve body toward the open end of the suction pipe

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

if the force exerted on the valve body by a suction refrigerant is greater than the biasing force of the coil spring, the coil spring contracts, and the valve body thus moves away from an open end face

Methodology Applied
Scientific EffectPressure force: Pressure Increase

Data Source

PatentEP4403776B1Scroll compressor and refrigeration apparatus
Publication Date: 2025.12.17 DAIKIN INDUSTRIES LTD
  • EP4403776B1 patent drawingFigure 1
  • EP4403776B1 patent drawingFigure 2
  • EP4403776B1 patent drawingFigure 3~4

AI summary

A suction check valve (80) includes a valve body (81), a valve seat (85), and a compression spring (88). The valve body (81) includes a first bottom portion (82), and a first circumferential wall (83) standing toward the valve seat (85) along a peripheral portion of the first bottom portion (82). The valve seat (85) includes a second bottom portion (86), and a second circumferential wall (87) standing toward the valve body (81) along a peripheral portion of the second bottom portion (86). One of the first circumferential wall (83) or the second circumferential wall (87) has an outside diameter smaller than an inside diameter of an open end of the other of the first circumferential wall (83) or the second circumferential wall (87).