Segmented Piston Ring Profile for Low Oil Consumption Sealing
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Solution Overview
Problem
Current piston rings for internal combustion engines have limitations in their constructive configuration, leading to inadequate sealing, increased oil consumption, and higher particle emissions, particularly during the run-in phase and initial engine operation.
Innovation Solution
A piston ring design featuring two segments and a spacer with a convex profile, wound using a matrix box device and roller, achieving circularity with Fourier series amplitudes less than 0.10 μm for orders higher than 10, and optionally coated with PVD or DLC, made from nitrated stainless or carbon steel, to enhance symmetry and reduce deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional three-roller winding process is used, then production simplicity is maintained, but ring circularity and symmetry are inadequate
Solution Approach 1:
The winding process is divided into multiple sequential stages: initial winding with first rollers, intermediate shaping with second rollers, and final precision shaping with third rollers. Each stage performs a specific function to progressively achieve the target circularity, breaking down the complex precision requirement into manageable steps.
Solution Approach 2:
The first rollers perform preliminary winding to create the basic ring form before subsequent rollers refine the circularity. This preliminary action allows later stages to focus on precision adjustments rather than creating the entire form from scratch, improving overall manufacturing precision while managing complexity.
2Reliability
If conventional piston ring design is used, then basic sealing function is provided, but oil consumption is excessive during run-in phase
Solution Approach 1:
The piston ring profile is designed with specific local characteristics including a convex portion with defined radius of curvature and asymmetric cross-section. These local quality modifications optimize the contact pressure distribution with the cylinder wall, improving sealing reliability while reducing oil consumption during the run-in phase.
Solution Approach 2:
The invention modifies key geometric parameters of the piston ring including the convex portion radius (0.05-0.15mm), segment height (0.30-0.40mm), and radial dimension (1.50-1.90mm). These parameter changes optimize the ring's interaction with the cylinder wall, achieving better sealing with reduced oil consumption.
3Manufacturing precision
If standard winding process is used, then production efficiency is maintained, but profile symmetry and offset are inadequate
Solution Approach 1:
The winding process uses multiple roller pairs (first, second, and third rollers) that work in sequence to achieve profile symmetry. Each roller pair addresses specific symmetry requirements, dividing the complex symmetry achievement into manageable stages that maintain production efficiency.
Solution Approach 2:
The invention replaces simple mechanical winding with a multi-roller system that incorporates precise positioning and controlled deformation. This mechanical substitution enables high-profile symmetry while maintaining productivity through optimized process flow.
Data Source
AI summary
A piston ring may include a spacer or expansion element and/or two segments. The segments may have a radial dimension between approximately 1.50 mm and approximately 1.90 mm and a height between approximately 0.30 mm and approximately 0.40 mm. The segments may have a concave profile with recesses between approximately 0.015 mm and approximately 0.030 mm and a clearance of approximately 0.150 mm. The segments may be wound via a matrix box device and a roller. The piston ring may have a circularity, expressed in the form of a decomposition as a Fourier series, with an amplitude for orders higher than 10 which is not greater than 0.10 μm.