Piston Ring Wear-Resistant Coating and Sacrificial Web Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piston rings, particularly compression piston rings, experience excessive wear and thermal overload due to high impact loads at the ring butt ends, which limits their service life despite existing measures like hard coatings and optimized ring shapes.
Innovation Solution
A piston ring design featuring a circumferentially formed chamber with a wear-resistant coating and a web extension made from the base material, which wears off during the break-in period, allowing the ring to run on its designated apex and develop a thicker oil film for improved lubrication, reducing thermal overload and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hard coatings are applied on the running surface, then wear resistance is improved, but impact overload at the butt ends cannot be prevented
Solution Approach 1:
The patent applies different material properties to different regions: a hard wear-resistant coating is applied to the running surface for wear protection, while the impact area at the butt ends remains as soft base material to absorb impact loads. This local differentiation of material properties resolves the contradiction between wear resistance and impact overload prevention.
2Object-affected harmful factors
If the ring shape is optimized to minimize impact pressure, then impact overload is reduced, but complete elimination of the phenomenon is not achieved
Solution Approach 1:
The patent introduces a sacrificial soft material layer at the impact area that is designed to wear off during the break-in period. This temporary, consumable element absorbs impact loads during the critical initial operation phase, protecting the ring until it reaches its designated apex, thereby extending service life.
3Strength
If a PVD coating is applied to the running surface, then wear protection is improved, but the impact area remains vulnerable due to coating discontinuity
Solution Approach 1:
The patent creates a local soft material region at the impact area that extends beyond the PVD coating edges. This localized soft zone provides impact absorption exactly where the hard coating would be discontinuous, complementing the PVD coating's wear protection while addressing its vulnerability at the boundaries.
4Reliability
If the ring operates with impact relief, then lubrication is improved and thermal overload is avoided, but this requires a break-in period during which the soft approach wears off
Solution Approach 1:
The patent prepares the ring with a soft approach material in advance before operation. During the break-in period, this pre-installed soft material performs the function of impact absorption and surface conditioning, enabling the ring to transition smoothly into its final operating state with proper lubrication and apex contact.
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 design achieves uniform wear and extended service life by minimizing impact pressure and enhancing lubrication in the impact area, preventing thermal overload and reducing wear.
Implementation Method 1
a wear-resistant coating, in particular a PVD coating
Implementation Method 2
this relatively soft approach wears off relatively quickly
Implementation Method 3
an oil film can develop in this area that is the same as or thicker than on the rest of the circumference of the piston ring. The improved or more uniform lubrication will avoid thermal overload
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a piston ring, in particular a compression piston ring, having a main body, which comprises a radially outer running surface, a radially inner circumferential surface, an upper and a lower flank surface and a joint, wherein the running surface is provided with at least one circumferentially formed recess, which receives a wear-resistant coating, in particular a PVD coating, wherein, starting from the web edges of the joint, viewed in the circumferential direction of the main body, outside the coating a joint shoulder is integrally formed with the main body and extends with a predeterminable radial height over a defined circumferential length on both sides of the joint.