Oil Control Ring Wiper Lip Segmentation and Anti-Wear Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Oil scraper rings in internal combustion engines face a challenge in balancing oil consumption and wear reduction, as existing designs struggle to maintain effective oil scraping and lubrication over long engine operating periods without excessive wear.

Innovation Solution

The oil scraper ring design features two radially outer lands with wiper lips, an anti-wear coating, and strategically adjusted flank angles, where the offset of wiper lips corresponds to the coating thickness, tripling the service life and maintaining a consistent oil film for reduced friction and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the oil scraper ring scrapes off more oil from the cylinder wall, then oil consumption is minimized, but the oil film between the ring and cylinder wall becomes too thin, increasing friction and wear

Engineering Contradiction:
Improveoil consumptionVSAvoidwear resistance
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The oil scraper ring is divided into multiple functional zones: a first wiper lip for initial oil scraping, a second wiper lip for secondary scraping, and an intermediate section with different surface properties. This segmentation allows each zone to perform its specific function optimally while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the oil scraper ring are given different surface qualities - the wiper lips have high friction coefficients for effective oil scraping, while the intermediate section has low friction coefficients to maintain lubrication and reduce wear. This local differentiation resolves the contradiction between oil scraping efficiency and wear resistance.

Inventive Principle:
Principle #3Local quality

2Reliability

If the oil scraper ring maintains a minimum oil film to reduce friction and wear, then lubrication is adequate, but oil consumption increases due to insufficient oil scraping

Engineering Contradiction:
Improvewear resistanceVSAvoidoil consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The ring is segmented into multiple wiper lips that progressively scrape oil, with the first lip removing excess oil and the second lip providing additional scraping. This multi-stage approach ensures thorough oil removal while maintaining adequate film thickness to prevent metal-to-metal contact.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The intermediate section between wiper lips is designed with low friction surface properties to maintain lubrication in critical areas, while the wiper lips themselves have high friction properties for effective oil scraping. This local quality differentiation allows the ring to both scrape oil efficiently and maintain protective oil films where needed.

Inventive Principle:
Principle #3Local quality

3Productivity

If the oil scraper ring operates for long periods, then engine productivity is maintained, but wear on the ring increases, enlarging the gap between the ring and cylinder wall and increasing oil consumption

Engineering Contradiction:
Improveengine operating timeVSAvoidwear resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The oil scraper ring is pre-coated with a low friction coating material before operation begins. This preliminary protective layer is designed to wear down gradually over time, providing wear protection during the initial high-wear period and extending the ring's service life while maintaining performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The friction coefficient of the ring surface is changed through the application of specialized coating materials with different tribological properties. The coating transitions from high friction (for initial oil scraping) to lower friction (for wear protection), allowing the ring to adapt to different operational phases and extend its service life.

Inventive Principle:
Principle #35Parameter changes

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 significantly extends the service life of the oil scraper ring by maintaining low wear and optimal oil control, ensuring reduced oil consumption and friction over extended engine operation.

Implementation Method 1

an anti-wear coating on each wiper lip

Methodology Applied
Scientific EffectAnti-wear coating: Coatings

Implementation Method 2

a minimum oil film must be maintained between the oil scraper ring and the cylinder wall at all times in order to keep friction and thus wear low

Methodology Applied
Scientific EffectFriction reduction: Friction

Implementation Method 3

By adjusting the flank angle of the wiper lips, the PVD or DLC layer is deposited homogeneously

Methodology Applied
Scientific EffectPVD deposition: Physical Vapour Deposition

Implementation Method 4

the PVD or DLC layer is deposited homogeneously

Methodology Applied
Scientific EffectDiamond-like carbon coating: Diamond-like Carbon

Implementation Method 5

a minimum oil film must be maintained between the oil scraper ring and the cylinder wall at all times in order to keep friction and thus wear low

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2531750B1Oil control ring
Publication Date: 2015.06.24 FEDERAL MOGUL BURSCHEID GMBH
  • EP2531750B1 patent drawingFigure 1~2
  • EP2531750B1 patent drawingFigure 3~4
  • EP2531750B1 patent drawingFigure 5~6

AI summary

The invention relates to an improved oil control ring, comprising a ring body (2), two radially outer projections (4) on the ring body (2), which are arranged one behind the other in the running direction of the piston and which are spaced apart from each other by an outer recess (6), wherein each projection (4) has two scraping lips (8); and a wear-protection coating (10) on each scraping lip (8).