Oil Control Ring Meander Spring Joint Sealing Against Oil Carryover
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Solution Overview
Problem
Stricter emissions regulations pose a challenge as oil entering the combustion chamber contributes significantly to particulate emissions, particularly during overrun operation when negative pressure in the combustion chamber causes increased oil suction from the crankcase.
Innovation Solution
The oil scraper piston ring design features legs of the meandering spring that run approximately parallel and are thinner than the joint width of the lamella element, allowing them to be guided with defined play within the joint, ensuring the tangential force is maintained while blocking oil passage by extending into the joint of the upper lamella element, thereby preventing oil from reaching the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the legs of the meandering spring are made longer to extend into the joint of the upper lamella element, then oil passage is blocked and sealing performance is improved, but the risk of jamming within the joint increases
Solution Approach 1:
The legs are designed with a specific thickness that is smaller than the joint width, creating a localized clearance fit in the circumferential direction. This allows the legs to extend into the joint for sealing while maintaining sufficient clearance to prevent jamming, thus resolving the contradiction between sealing performance and operational reliability.
2Ease of operation
If the thickness of the legs is reduced to allow guided movement within the joint, then ease of operation is improved, but the structural strength may be compromised
Solution Approach 1:
The leg thickness is optimized to a specific parameter range that is smaller than the joint width, allowing guided movement with defined play in the circumferential direction. This parameter optimization ensures both ease of operation for the guided movement and sufficient structural strength to maintain tangential force, resolving the contradiction between operational ease and structural strength.
3Ease of operation
If the legs are made thinner than the joint width to allow defined play, then ease of operation is improved, but sealing effectiveness may be reduced
Solution Approach 1:
The clearance fit is implemented specifically in the circumferential direction (one dimension), allowing defined play and ease of operation. Meanwhile, the legs maintain sufficient contact in the axial direction to provide effective sealing. This dimensional differentiation resolves the contradiction between ease of operation 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
This design effectively reduces oil entry into the combustion chamber, thereby minimizing particle emissions by creating a sealing closure that blocks axial oil flow, ensuring compliance with stricter emissions regulations.
Implementation Method 1
the legs of the meander spring engaging in the joint of the upper lamella element... blocking oil passage by extending into the joint of the upper lamella element, thereby preventing oil from reaching the combustion chamber
Implementation Method 2
maintaining the tangential force of the lamella element
Data Source
Figure 1~3
AI summary
The invention relates to a multi-part oil control ring (1), comprising a slotted spring element and at least one lamella element (3, 4), which is operatively connected to the spring element and is provided with a butt joint (7). The spring element is in the form of a meander spring (2) that axially receives and radially supports the lamella element. The two end regions of the meander spring are provided with legs (9, 10) running approximately parallel to each other, the axial length of which legs is such that the legs at least partly engage in the butt joint of the lamella element.