Track Link Lug Contours for Sprocket Engagement

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Solution Overview

Problem

Existing continuous track systems for mobile machines face challenges in maintaining optimal engagement and alignment with drive sprockets and rollers, leading to wear and misalignment issues, which affect traction and component longevity.

Innovation Solution

The design of a track link with a contoured upper surface and specific lug arrangements facilitates improved rolling engagement with drive sprockets and rollers, featuring pin lugs with offset pin bores, sprocket lugs with rail protrusions, and roller lugs that enhance contact and alignment, allowing for better distribution of weight and reduced wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional flat track link designs are used, then manufacturing is simpler, but engagement with drive sprockets and rollers is poor leading to wear and misalignment

Engineering Contradiction:
Improveengagement qualityVSAvoidtrack link structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The track link incorporates a contoured upper surface with curved engagement surfaces that conform to the cylindrical shapes of drive sprockets and rollers. This curvature enables continuous rolling contact rather than point or line contact, significantly improving engagement quality and reducing wear while the contours are integrated into the basic link structure

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The track link features localized contoured surfaces specifically at the engagement zones with drive sprockets and rollers, while other portions of the link maintain simpler geometries. This applies the complexity only where needed for improved engagement, balancing reliability enhancement with manufacturing feasibility

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If track links have basic lug arrangements, then manufacturing is easier, but alignment with drive components is poor causing misalignment issues

Engineering Contradiction:
Improvealignment precisionVSAvoidtrack link fabrication
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The lugs incorporate contoured engagement surfaces with specific radii that match the curvature of drive sprockets and rollers. These curved surfaces guide the track link into proper alignment during engagement, ensuring precise positioning while the overall lug geometry remains manufacturable using standard forming processes

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The contoured surfaces on the lugs are designed to initially contact the drive sprockets and rollers at predetermined points, guiding the track link into correct alignment before full engagement occurs. This preliminary alignment action prevents misalignment issues while maintaining straightforward lug construction

Inventive Principle:
Principle #10Preliminary action

3Productivity

If simple track link surfaces are used, then manufacturing is less complex, but contact duration with drive components is reduced affecting traction

Engineering Contradiction:
Improvetraction efficiencyVSAvoidsurface geometry
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The contoured upper surfaces create extended contact zones with drive sprockets and rollers through curved geometries that maintain surface contact over longer portions of the engagement cycle. This increases the duration and quality of contact, improving traction efficiency while the contours are integrated into the basic link casting or forming process

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3341269B1Undercarriage assembly and track links for assembly
Publication Date: 2020.11.25 CATERPILLAR INC
  • EP3341269B1 patent drawingFigure 1
  • EP3341269B1 patent drawingFigure 2
  • EP3341269B1 patent drawingFigure 3

AI summary

An undercarriage assembly (116) for a mobile machine (100) includes a continuous track (120) having a plurality of mated track links (122) that can translate with respect to the machine (100). Each track link (122) may include a shoe portion (150) and a body portion (160). The body portion (160) includes a plurality of projecting pin lugs (160) each having a pin bore (168) to receive a pin and link adjacent track links (122) together. The pin lugs (160) can include a pair of sprocket lugs (190) for making rolling contact with a sprocket (142), a pair of roller lugs (200) for making rolling contact with a plurality of rollers (140), and a side lug (210) having a protruding shoulder (212) to assist in aligning the plurality of rollers (140).