Shaft Coupling Arrangement Preventing Torque-Induced Breakage

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Solution Overview

Problem

Existing coupling mechanisms for shafts are susceptible to breakage when high torque is applied, as they often rely on physical barriers that can be forced open, and they struggle to be compact and energy-efficient for battery-powered operation.

Innovation Solution

A coupling arrangement featuring a first and second shaft with a circular and sleeve-shaped coupling member, respectively, along with a selecting element and spherically shaped locking elements that allow for free rotation in the engaged configuration and disengagement, reducing susceptibility to torque-induced breakage and facilitating easy assembly/disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a physical barrier mechanism is used to prevent rotation, then security is improved, but the mechanism becomes susceptible to forced breakage

Engineering Contradiction:
ImprovesecurityVSAvoidresistance to forced breakage
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The coupling mechanism transitions from a static physical barrier to a dynamic system where the first coupling member can rotate freely within the second coupling member when disengaged. The spherical locking elements dynamically move between locked (engaged) and unlocked (disengaged) positions, allowing the mechanism to adapt its state based on operational requirements rather than relying on rigid physical barriers that can be forced.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spherical locking elements act as intermediaries between the engaged and disengaged states. When positioned in the through-holes, they mediate the locked state by preventing relative rotation. When removed from the through-holes, they allow free rotation. This intermediary mechanism provides security without creating rigid physical barriers susceptible to forced breakage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If a compact coupling mechanism is designed for integration into handles or lock cylinders, then device size is reduced, but torque transmission reliability may be compromised

Engineering Contradiction:
Improvemechanism sizeVSAvoidtorque transmission
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The first coupling member is nested within the second coupling member, with the outer surface of the first coupling member rotatably housed within the inner surface of the second coupling member. This nested arrangement achieves a compact design suitable for integration into handles or lock cylinders while maintaining reliable torque transmission through the engagement of spherical locking elements in the through-holes.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The use of spherical locking elements provides curved surfaces that distribute contact forces more evenly compared to flat or angular interfaces. The spherical shape allows for smooth engagement and disengagement while maintaining reliable torque transmission in the engaged state, and enables easy movement between states without requiring excessive force.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If a coupling mechanism uses significant energy to operate, then reliable engagement/disengagement is achieved, but battery life is reduced

Engineering Contradiction:
Improveengagement reliabilityVSAvoidoperating energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The spherical locking elements are designed to be movable between the through-holes and the grooves on the outer surface of the first coupling member with minimal force requirement. The geometry of the through-holes and grooves allows the locking elements to be positioned into engagement or disengagement positions through simple rotational movement of the second coupling member, enabling reliable operation with minimal energy input from battery-powered actuators.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3788220B1Coupling arrangement for selectively engaging and disengaging a first and a second shaft
Publication Date: 2023.06.07 AXEMA ACCESS CONTROL AB
  • EP3788220B1 patent drawingFigure 1~2
  • EP3788220B1 patent drawingFigure 3
  • EP3788220B1 patent drawingFigure 4a~4c

AI summary

The present inventive concept relates to a coupling arrangement for selectively engaging and disengaging a first and a second shaft extending coaxially along an axis A. The coupling arrangement comprises: a first coupling member, and a second coupling member comprising a sleeve shaped, wherein the first coupling member is configured to be rotatably housed within the sleeve shaped element; a selecting element; and at least one locking element; wherein the coupling arrangement is configured to assume an engaged configuration, and a disengaged configuration.