Small End Bushing Protrusions for Controlled Piston Wear

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing combustion engine systems experience unpredictable and uneven wear at the contact surfaces between the small end bushing and the piston, leading to reduced lifespan and increased maintenance costs due to the lack of controlled abrasive wear zones.

Innovation Solution

The introduction of bushings and pistons with specifically designed protrusions that create a controlled abrasive wear zone, allowing for targeted lubrication and coating to extend the lifespan of the components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bushings with uniform contact surfaces are used, then the structure is simple and easy to manufacture, but the wear pattern is unpredictable and uneven leading to reduced component lifespan

Engineering Contradiction:
Improvecomponent lifespanVSAvoidbushing structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bushing incorporates protrusions at specific locations on its contact surface, creating localized areas with different geometric properties. These protrusions concentrate contact forces into defined zones, ensuring predictable wear patterns occur at specific locations rather than uniformly across the entire contact surface, thereby improving reliability while maintaining relatively simple manufacturing processes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The contact surface of the bushing is segmented into distinct regions by the protrusions, creating separate contact zones. This segmentation allows different parts of the contact surface to serve different functions, with protrusions defining specific wear paths and allowing lubrication to be targeted at critical areas, thus extending component lifespan without significantly complicating the overall structure.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If protrusions are added to create controlled wear zones, then wear becomes predictable and reproducible, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvewear zone controlVSAvoidbushing fabrication
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Rather than requiring complex precision machining of the entire bushing surface, the invention applies local quality modifications through protrusions at specific critical locations. This approach achieves controlled wear zones by modifying only the necessary areas, maintaining manufacturing simplicity while achieving the precision needed for predictable wear patterns.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The protrusions are pre-formed as integral parts of the bushing during the manufacturing process, rather than being added as separate components or requiring complex post-processing. This preliminary action ensures precise wear zone control is built into the component design itself, achieving manufacturing precision without significantly increasing fabrication complexity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the entire contact surface is lubricated and coated, then wear is reduced across all areas, but the cost and complexity of maintenance increases

Engineering Contradiction:
Improvewear reductionVSAvoidlubrication system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protrusions create localized contact zones that concentrate wear in specific areas, allowing lubrication and protective coatings to be applied only to these critical regions rather than the entire contact surface. This local approach maintains effective wear reduction while significantly simplifying the lubrication system and reducing maintenance complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention extracts the lubrication requirement from the entire contact surface and concentrates it only at the protrusion contact zones. By removing the need for universal lubrication and focusing it only where wear actually occurs, the system achieves effective wear protection with a simpler, more cost-effective lubrication and coating strategy.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If uniform contact surfaces are used, then the design is simple, but friction and wear are distributed unevenly reducing efficiency

Engineering Contradiction:
Improveengine efficiencyVSAvoidcontact surface geometry
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The protrusions create localized contact zones that optimize friction management at critical areas. By concentrating contact forces into defined regions, the design achieves more efficient load distribution and reduced overall friction compared to uniform surfaces, thereby improving engine efficiency without requiring complex multi-component systems.

Inventive Principle:
Principle #3Local quality

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 solution enables a predictable and reproducible wear pattern, reducing friction and wear, thereby increasing the lifespan of the bushing and piston while minimizing maintenance costs by focusing lubrication and coating efforts on specific wear areas.

Implementation Method 1

a running wear occurs along a running wear zone where the bushing end surfaces and the inner piston surfaces contact each other

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a running wear (wear and tear) may occur at the defined contact zone

Methodology Applied
Scientific EffectWear: Wear

Implementation Method 3

the region where the running wear occurs may be easily and reliably lubricated and/or coated for reducing the running wear

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2515010B1Small end bushing, piston and bushing-piston-system
Publication Date: 2016.09.28 CATERPILLAR MOTOREN GMBH & CO KG
  • EP2515010B1 patent drawingFigure 1
  • EP2515010B1 patent drawingFigure 2
  • EP2515010B1 patent drawingFigure 3~4

AI summary

A bushing (40, 40A, 40B) having a middle axis and adapted for being inserted in an axial direction into a small end eye (31) of a connecting rod (100) may comprise a first bushing end surface (43) at a first axial end of the bushing (40, 40A, 40B), the first bushing end surface (43) forming at least one protrusion (90A, 90B) extending in the direction of the middle axis and defining a contact region at the first axial end of the bushing (40, 40A, 40B) adapted for contacting, in the mounted state, a first inner surface (68) of a piston (60).