Robot Arm Extension Joint With Guide Rollers for Stable Gear Engagement

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Solution Overview

Problem

Conventional robot arm mechanisms with linear extension and retraction joints experience instability in extension and retraction motion due to misalignment and deviation of connection piece strings from their designed path.

Innovation Solution

A robot arm mechanism with a linear extension and retraction joint that includes a first connection piece string with U-shaped or arc cross-section and a second connection piece string with a flat plate shape, guided by a guide section with rollers, ensuring stable engagement and retraction by maintaining the engaged state of the linear gear and drive gear through a specific arrangement of guide rollers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If connection piece strings are moved out of a designed path, then the extension and retraction motion becomes unstable, but adding guide rollers increases device complexity

Engineering Contradiction:
Improvestability of extension and retraction motionVSAvoidcomplexity of guide section
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Guide rollers are introduced as intermediary components between the connection piece strings and the ejection section. These rollers act as mediators that redirect and control the movement path of the connection piece strings, ensuring they follow the designed trajectory while reducing direct contact and friction with the ejection section walls

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The guide section is segmented into multiple guide rollers arranged at different positions rather than using a single complex guiding structure. Each guide roller independently manages a specific segment of the connection piece string path, allowing for modular design and easier maintenance

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If multiple guide rollers are used to keep the engaged state of linear gear and drive gear, then misalignment is prevented, but manufacturing cost increases

Engineering Contradiction:
Improvealignment precision of connection piece stringsVSAvoidmanufacturing ease of guide section
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The guide rollers are designed with varying diameters - the first guide roller has a larger diameter than the second guide roller. This parameter change optimizes the guiding effect at different stages: the larger first roller provides stable initial guidance and engagement, while the smaller second roller maintains precision during the retraction phase

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Different guide rollers are positioned at specific locations along the movement path with tailored diameters and orientations. The first guide roller is positioned to handle the initial engagement phase with larger diameter for stability, while the second guide roller is positioned for precision maintenance during retraction with smaller diameter

Inventive Principle:
Principle #3Local quality

3Strength

If connection piece strings are joined to form columnar body, then rigidity is improved, but the strings may deviate from designed path during movement

Engineering Contradiction:
Improverigidity of columnar bodyVSAvoidpath stability of connection piece strings
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

Guide rollers serve as intermediary elements that support the joined connection piece strings without restricting their rigid structure. The rollers contact the columnar body at specific points, providing guidance while allowing the rigid columnar structure to maintain its strength and load-bearing capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3235608B1Robot arm mechanism
Publication Date: 2021.05.19 LIFE ROBOTICS CO LTD
  • EP3235608B1 patent drawingFigure 1~2
  • EP3235608B1 patent drawingFigure 3
  • EP3235608B1 patent drawingFigure 4A~4B

AI summary

A stable extension and retraction motion is realized in a robot arm mechanism including a linear extension and retraction joint. In the robot arm mechanism including the linear extension and retraction joint, the linear extension and retraction joint includes an arm section (2), and an ejection section (30) for supporting the arm section (2). The arm section (2) includes a first connection piece string (21) and a second connection piece string (20). The first connection piece string (21) includes a plurality of first connection pieces (23). The second connection piece string (20) includes a plurality of second connection pieces (22) each having a substantially flat plate shape. The first connection piece string (21) is joined to the second connection piece string (20) to thereby constitute a columnar body. The columnar body is sent out forward from the ejection section (30). A guide roller (411) for guiding the second connection piece string (20) to the ejection section (30) and keeping an engaged state of a linear gear (22a) provided on the second connection piece (22) and a drive gear (24a) is provided behind the ejection section (30).