Combination Link Layout to Prevent Actuator Interference

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional combination type link actuation devices face challenges in achieving high-speed and high-accuracy operations over wide ranges while maintaining a compact size, often resulting in interference between orientation controlling actuators and requiring larger workpiece transporting tools due to increased distances between workpieces.

Innovation Solution

The design incorporates two link actuation devices with three link mechanisms aligned in a circumferential direction, featuring at least one separation angle greater than 120°, allowing the devices to be positioned closely without interference, and a two-degrees-of-freedom mechanism that enables ±90° bend angles and 0° to 360° traverse angles, facilitating compact operation and reduced space occupancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If three link mechanisms are disposed at equal intervals (120° separation angles) in conventional link actuation devices, then the orientation controlling actuators can control the distal end side link hub orientation, but the actuators from two different link actuation devices interfere with each other when the devices are positioned close to each other

Engineering Contradiction:
Improveorientation control capabilityVSAvoidactuator interference
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by setting the separation angles of the three link mechanisms to specific asymmetric values (135°, 135°, and 90°) rather than equal 120° intervals. This asymmetric configuration positions the orientation controlling actuators such that they do not interfere with each other when two link actuation devices are placed close together, while still maintaining full orientation control capability of the distal end side link hub.

Inventive Principle:
Principle #4Asymmetry

2Volume of moving object

If two link actuation devices are positioned close to each other to reduce overall device size, then compactness is improved, but the orientation controlling actuators from different devices interfere with each other

Engineering Contradiction:
Improveoverall device sizeVSAvoidactuator interference
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

By configuring the link mechanisms with asymmetric separation angles (135°, 135°, 90°), the actuators are positioned in a pattern that avoids overlap and interference even when two devices are placed in close proximity. This allows the system to achieve compact dimensions while maintaining independent operation of each actuator.

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If the distance between workpieces is increased to avoid actuator interference, then actuator interference is eliminated, but the workpiece transporting tool size must be increased

Engineering Contradiction:
Improveactuator interferenceVSAvoidworkpiece transporting tool size
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The asymmetric separation angle configuration (135°, 135°, 90°) allows link actuation devices to be positioned closer together without actuator interference, which in turn enables the use of smaller workpiece transporting tools. The asymmetric arrangement optimizes the spatial distribution of actuators to minimize the required distance between workpieces.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3354420B1Combination type link actuation device
Publication Date: 2022.12.07 NTN CORP
  • EP3354420B1 patent drawingFigure 1
  • EP3354420B1 patent drawingFigure 2
  • EP3354420B1 patent drawingFigure 3

AI summary

A combination link actuation device (1) has two link actuation devices (7) combined with each other. Each link actuation device (7) is provided so as to connect a distal end side link hub (13) to a proximal end side link hub (12) such that an orientation of the distal end side link hub (13) is changed relative to the proximal end side link hub (12) through three link mechanisms (14) aligned in a circumferential direction. An orientation controlling actuator (10) is provided in two or more link mechanisms (14) among the three link mechanisms (14) to optionally change an orientation of the distal end side link hub (13) relative to the proximal end side link hub (12). At least one circumferential separation angle (δ1) among separation angles (δ1, δ2, δ3) of the three link mechanisms (14) is greater than 120°. The two link actuation devices (7) are disposed such that portions, of the link mechanisms (14), where the separation angle (δ1) is greater than 120° oppose each other.