Compressor Discharge Valve Stopper Design
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Solution Overview
Problem
In hermetic reciprocating compressors, discharge valve adhesion to the stopper due to oil causes premature opening and closing issues, leading to refrigerant gas discharge loss and reduced compressor capacity, as the discharge passage remains open during the suction process.
Innovation Solution
The stopper on the valve plate features cut-outs and protrusions to reduce the contact area between the discharge valve and the stopper, minimizing adhesion forces and allowing the discharge valve to open and close more efficiently, with gas pressure aiding in the opening process, thus preventing gas recirculation back into the cylinder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the discharge valve contacts the stopper over a large area to ensure stable positioning, then the positioning stability is improved, but the adhesion force due to oil increases causing the valve to remain stuck open
Solution Approach 1:
The stopper surface is segmented into multiple discrete contact points (protrusions) rather than a continuous large-area surface. This segmentation reduces the total contact area between the discharge valve and stopper, thereby minimizing oil adhesion while still providing stable positioning through distributed contact points.
Solution Approach 2:
The stopper is designed with localized protrusions that create specific contact zones on the discharge valve. This local quality approach ensures that contact occurs only at predetermined locations with optimized surface characteristics, reducing overall adhesion while maintaining functional stability.
2Stress or pressure
If the discharge valve opens fully to maintain desired gas pressure, then the pressure control is improved, but the valve may stick to the stopper due to oil adhesion and fail to close properly
Solution Approach 1:
The stopper contact surface is divided into multiple small protrusions rather than a large continuous area. This segmentation allows the valve to open fully for pressure control while minimizing the total contact area that would cause oil adhesion, enabling proper valve closure and maintaining compressor capacity.
Solution Approach 2:
The design accepts that oil adhesion is inevitable but converts this potential harm into a benefit by using small protrusions that limit adhesion to minimal areas. This allows the valve to function reliably despite the presence of oil, transforming the adhesion issue from a critical problem into a manageable design consideration.
3Stability of the object's composition
If the contact area between discharge valve and stopper is large to ensure stable opening constraint, then the constraint stability is improved, but the adhesion effect increases causing premature opening and discharge loss
Solution Approach 1:
The stopper contact area is segmented into multiple small protrusions distributed across the valve surface. This segmentation maintains constraint stability through distributed contact points while minimizing the total contact area, thereby reducing oil adhesion and preventing discharge loss.
Solution Approach 2:
Instead of providing full-area contact for constraint stability, the design uses partial contact through protrusions at strategic locations. This partial action is sufficient to maintain stability while avoiding the excessive contact area that would cause harmful adhesion effects.
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 design enhances compressor efficiency by reducing thermodynamic losses and maintaining desired pressures, preventing refrigerant gas from receding back into the cylinder, thereby increasing compressor capacity and performance.
Implementation Method 1
the discharge valve that contacts the stopper may adhere to the stopper due to the adhesion force of oil
Implementation Method 2
the contact of the upper surface of the discharge valve with the high pressure gas in the discharge chamber is provided by means of the cut-out formed on the stopper, thus gas pressure acts on the upper surface of the discharge valve decreasing the pressure imbalance
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A compressor (1) that is utilized in cooling devices comprising a cylinder (3), a piston (4) operating in the cylinder (3), a cylinder head (5), a valve plate (6) disposed between the cylinder (3) and the cylinder head (5), a suction chamber (7) under the cylinder head (5), a discharge chamber (8), an inlet passage (9) and a discharge passage (10) situated on the valve plate (6) providing entry and exit of the refrigerant fluid in the suction and discharge chambers (7, 8) into/from the cylinder (3), a suction valve (11) situated on one side of the valve plate (6), that opens and closes the inlet passage (9) during the reciprocation of the piston (4) and a discharge valve (12) on the other side of the valve plate (6), that opens and closes the discharge passage (10) during the reciprocation of the piston (4) wherein the discharge valve (12) is provided to open and close at the right time by modifications on the discharge valve (12) and the stopper (13) thereby increasing efficiency.