Scroll Compressor Control Valve Sealing Design
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Solution Overview
Problem
Existing control valves for scroll compressors face issues with external fluid leakage through the reference pressure chamber due to defects or low-quality rubber seals, leading to refrigerant release into the atmosphere.
Innovation Solution
A control valve design where the reference pressure chamber is a sealed space within the body, eliminating the need for external air introduction and preventing fluid leakage, with a power element that senses both suction and back pressures to adjust the valve opening, and a structure that includes diaphragms and disc springs for high pressure resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rubber seals are used to seal the reference pressure chamber in existing control valves, then the structure can be simplified and assembly can be easier, but fluid leakage occurs due to defects or low-quality rubber
Solution Approach 1:
The patent removes the rubber seal component entirely from the reference pressure chamber sealing system. Instead of using rubber seals that require quality control and proper installation, the invention uses a rigid sealing structure where the reference pressure chamber is sealed by the valve body structure itself and a fixed seal ring, eliminating the unreliable rubber seal while maintaining assembly simplicity.
Solution Approach 2:
The patent employs a composite sealing approach combining a rigid seal ring (made of metal or rigid plastic) with a precise mating surface in the valve body. This composite structure provides both the sealing reliability needed to prevent refrigerant leakage and the manufacturing simplicity required for easy assembly, replacing the single-material rubber seal solution.
2Reliability
If a sealed reference pressure chamber is used within the valve body, then external leakage is prevented, but the structure becomes more complex
Solution Approach 1:
The patent merges the reference pressure chamber sealing function with the existing valve body structure. The reference pressure chamber is formed as an integrated cavity within the valve body, sealed by a fixed seal ring that is part of the valve assembly structure rather than a separate component. This integration prevents leakage while avoiding additional complexity.
Solution Approach 2:
The valve body structure serves multiple functions: it houses the valve elements, provides fluid passages, and simultaneously forms the sealed reference pressure chamber. The seal ring serves dual purposes of sealing the reference pressure chamber and providing a mounting surface for internal components. This multi-functionality prevents leakage without increasing overall structural complexity.
3Ease of operation
If external air introduction is used for the reference pressure chamber, then the chamber can be filled with reference pressure, but refrigerant may leak to the atmosphere through defects
Solution Approach 1:
The patent converts the potential harm of having a separate external reference pressure system (which could leak) into a benefit by integrating the reference pressure chamber completely within the sealed valve body. The reference pressure is now established once during manufacturing in a controlled environment, and the sealed structure prevents any refrigerant leakage to the atmosphere, turning the sealing requirement from a potential failure point into a protective feature.
Solution Approach 2:
The reference pressure chamber is sealed as an inert, closed environment within the valve body, isolated from the external atmosphere. This sealed inert environment prevents refrigerant from escaping to the atmosphere even if defects are present in other parts of the valve, as the reference pressure chamber itself cannot leak externally. The chamber is filled with reference pressure gas during manufacturing and then hermetically sealed.
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 solution effectively controls back pressure variation with discharge and suction pressures, prevents external refrigerant leakage, and simplifies the compressor structure by eliminating the need for external reference pressure introduction, enhancing control accuracy and reducing costs.
Implementation Method 1
a valve element that operates depending on pressures in at least the two pressure chambers, and moves toward or away from the valve hole to adjust an opening degree of a valve section
Implementation Method 2
a reference pressure chamber being a sealed space formed between any two of the pressure chambers
Data Source
Figure 1
Figure 2
AI summary
A control valve (1) includes: a body (2) having a discharge pressure chamber (20), a first pressure chamber (22), a suction pressure chamber (28), a second pressure chamber (30), a valve hole (24), and a reference pressure chamber (S); and a valve element (36) that moves toward and away from the valve hole (24) to adjust the opening degree of the valve section. The reference pressure chamber (S) is a sealed space formed between any two of the pressure chambers. The valve element (36) operates depending on the pressures in at least the two pressure chambers.