Link actuating device, and origin positioning method

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Solution Overview

Problem

Existing spherical surface link mechanisms face limitations in rigidity, interference, and cable protection, which affect positioning accuracy and operational smoothness, while also being costly to manufacture.

Innovation Solution

The introduction of intermediate link hubs and bearings in the spherical surface link mechanism, which improve rigidity, reduce friction, and facilitate cable insertion, while allowing for easier installation of driving sources and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If intermediate link hubs and bearings are introduced to improve rigidity and reduce friction, then positioning accuracy and operational smoothness are enhanced, but device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The link mechanism is divided into multiple segments with intermediate link hubs inserted between the proximal and distal end link hubs. These intermediate hubs create additional rotation points that improve the rigidity of the overall structure while maintaining spherical surface movement characteristics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Bearings are introduced as intermediary components between the link members and intermediate link hubs to reduce friction. These bearings act as mediators that enable smooth rotation while supporting the increased structural rigidity provided by the intermediate hubs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If intermediate link hubs are added to suppress cable deflection and interference, then cable protection is improved, but manufacturing cost increases

Engineering Contradiction:
Improvecable deflection and interferenceVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

By segmenting the link mechanism with intermediate hubs, the cable path is better controlled and guided through the additional rotation points. This segmentation prevents cable deflection and interference while the modular design allows for standardized manufacturing of the hub components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The intermediate link hubs and bearings work together to automatically guide and protect the cable throughout the range of motion. The structural rigidity provided by the intermediate hubs naturally suppresses cable deflection without requiring additional active control mechanisms, making the system self-protecting.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If bearings are introduced to reduce friction, then operational smoothness is enhanced, but device complexity increases

Engineering Contradiction:
Improveoperational smoothnessVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Bearings are introduced as intermediary components between the link members and intermediate link hubs to reduce friction. These bearings act as mediators that enable smooth rotation while supporting the increased structural rigidity provided by the intermediate hubs.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The introduction of bearings changes the friction parameter of the rotation joints from high to low. This parameter change enables smooth operation throughout the spherical surface movement, transforming the operational characteristics of the entire mechanism.

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

The improved rigidity and reduced friction enhance positioning accuracy and operational smoothness, while also lowering manufacturing costs and suppressing cable deflection and interference.

Implementation Method 1

The spherical surface link mechanism includes a proximal end link hub, a distal end link hub, a plurality of links, a plurality of intermediate link hubs, and a bearing. The bearing reduces friction between rotating components, enabling smooth rotation and movement.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4520482B1Link actuating device, and origin positioning method
Publication Date: 2026.04.15 NTN CORP
  • EP4520482B1 patent drawingFigure 1
  • EP4520482B1 patent drawingFigure 2
  • EP4520482B1 patent drawingFigure 3

AI summary

A link actuating device comprises: a spherical surface link mechanism; and an origin positioning member, wherein the spherical surface link mechanism includes a proximal end link hub, a distal end link hub, a plurality of links, and a plurality of intermediate link hubs, each of the plurality of links includes a first end link member, a second end link member, and an intermediate link member, the first end link member is coupled, at one end of the first end link member, to the proximal end link hub to be rotatable about a first rotation axis, the second end link member is coupled, at one end of the second end link member, to the distal end link hub to be rotatable about a second rotation axis, the intermediate link member is coupled, at one end of the intermediate link member, to another end of the first end link member to be rotatable about a third rotation axis and is coupled, at another end of the intermediate link member, to another end of the second end link member about a fourth rotation axis