Robot Speed Reducer Coupling for Falling-Off Prevention

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Solution Overview

Problem

Existing falling-off prevention devices for transmissions in industrial robots are inadequate, as they may fail to prevent the transmission from falling off even when the recess on the robot side is damaged, necessitating a more secure solution, especially in robots that work closely with humans.

Innovation Solution

A transmission with a falling-off prevention feature that includes a coupling member, shaped like a string, which maintains coupling between the transmission and the mating member, even during displacement, eliminating the need for special designs like projections on the hold flange, thereby enhancing design flexibility and versatility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a recess is provided in the plate on the robot side to prevent transmission falling off, then the transmission can be retained on the robot, but the retention fails when the recess or casing is damaged

Engineering Contradiction:
Improveretention reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A coupling member is introduced as an intermediary component between the transmission and the robot plate. This coupling member includes a first coupling member fixed to the transmission casing and a second coupling member fixed to the robot plate, connected by a flexible coupling portion. This intermediary structure provides redundant retention paths, so if one connection point fails, the flexible coupling portion can compensate and maintain the connection, significantly improving retention reliability without requiring complex modifications to the original recess structure

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a projection is provided on the hold flange of the transmission casing to prevent falling off, then the transmission can be secured to the robot, but additional processing is required on the transmission

Engineering Contradiction:
Improvefalling-off preventionVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The falling-off prevention function is segmented from the transmission casing itself and transferred to a separate coupling member. The first coupling member is fixed to the transmission casing using standard fixing members, while the second coupling member attaches to the robot plate. This segmentation allows the transmission casing to maintain its original simple structure without requiring additional projections or modifications, while still achieving secure attachment through the separate coupling mechanism

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If the transmission is securely coupled to the mating member to prevent displacement, then the transmission remains fixed during operation, but the coupling must accommodate potential displacement without failing

Engineering Contradiction:
Improvecoupling stabilityVSAvoidcoupling maintenance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The coupling member incorporates a flexible coupling portion that can dynamically adapt to displacement between the transmission and robot plate. This flexible portion allows the coupling to maintain stability during normal operation while automatically compensating for any relative displacement or misalignment that occurs, ensuring the coupling remains intact and functional under varying operational conditions

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4092202B1Transmission with falling-off prevention feature
Publication Date: 2024.08.14 NABTESCO CORP
  • EP4092202B1 patent drawingFigure 1
  • EP4092202B1 patent drawingFigure 2
  • EP4092202B1 patent drawingFigure 3

AI summary

A speed reducer (100) with a falling-off prevention feature according to an aspect of the invention includes: a speed reducer (1) for decelerating rotation from a drive source that generates a rotational force and outputting the decelerated rotation, the speed reducer (1) being mounted to a robot; and a coupling member (51, 52, 53) for coupling the speed reducer (1) to the robot. The coupling member (51, 52, 53) maintains coupling between the speed reducer (1) and the robot (R) irrespective of displacement of the speed reducer (1) relative to the robot (R).