Piston Scraping Ring Power Groove Combustion Pressure
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Solution Overview
Problem
Internal combustion engine piston-cylinder assemblies face issues with carbon buildup, premature ring fatigue, and excessive blow-by due to non-uniform heat distribution and dimensional variations, leading to reduced engine efficiency and power loss.
Innovation Solution
A piston scraping ring with a curved or hook-shaped 'power groove' feature that expands and reverses the direction of combustion pressure waves, reducing pressure on piston rings and improving sealing between the piston and cylinder sleeve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a piston scraping ring is used to scrape carbon deposits, then carbon build-up is removed, but the ring experiences high pressure from combustion waves causing wear and fatigue
Solution Approach 1:
The patent converts the harmful combustion pressure waves into a beneficial force by designing a hook-shaped feature that redirects these waves to act against the piston crown and carbon deposits. The pressure waves that would otherwise damage the ring are now used to scrape carbon build-up, reducing ring wear and preventing fatigue failure while maintaining reliable carbon removal
Solution Approach 2:
Instead of having the piston ring directly resist combustion pressure waves, the invention inverts the approach by using the pressure waves to perform the scraping function. The hook-shaped feature redirects the pressure waves to act against the carbon deposits on the piston crown, reversing the traditional role where the ring both seals and scrapes under direct pressure
2Temperature
If clearance is increased between the piston ring and cylinder sleeve to allow thermal expansion, then thermal deformation is accommodated, but sealing capability deteriorates and blow-by increases
Solution Approach 1:
The patent applies local quality by creating a concentrated sealing zone at the hook-shaped feature where the ring makes intimate contact with the piston crown. This localized high-contact-area region provides effective sealing against blow-by, while the rest of the ring maintains sufficient clearance to accommodate thermal expansion and deformation without compromising overall sealing capability
Solution Approach 2:
The hook-shaped feature introduces a curved geometry that conforms to the piston crown surface, improving contact and sealing. The curved profile allows the ring to adapt to thermal deformation and non-uniform heating while maintaining a close fit that prevents gas leakage, resolving the contradiction between thermal expansion clearance and sealing effectiveness
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 power groove feature reduces wear and blow-by, enhances sealing capability, and prevents carbon buildup, thereby improving engine efficiency and durability by mitigating the impact of combustion pressure waves on piston rings.
Implementation Method 1
The inner surface has a feature capable of expanding and reversing the direction of a combustion pressure wave to reduce the pressure on the one or more piston rings
Data Source
AI summary
A device and method for preventing and removing piston deposit build-up on a piston cylinder assembly of an engine, including a diesel engine, is disclosed. A cylinder having an inner sleeve for receiving a piston, has a piston scraping ring positioned on the cylinder sleeve. The piston scraping ring includes an inner surface, and has a curved or hook shaped feature on its inner surface. The curved or hook shaped feature, named the ‘power groove’ for the purposes of this application, allows for reduced wear between the piston rings and the cylinder sleeve by reducing the pressure on the piston rings by expanding and reversing the flow of combustion gases. Additionally, this reversal of the combustion gases results in a decrease in blow-by gases passing between the piston rings and cylinder sleeve thereby improving sealing between the piston and the cylinder.