Frictional Connection Actuation via Shape Memory Alloy

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Solution Overview

Problem

Existing mechanical brake and clutch devices require external energy sources for activation, increasing complexity and reducing efficiency in controlled power transmission and temperature-dependent operations.

Innovation Solution

A device utilizing a toggle lever or web-like extension mechanism with shape-memory alloy (SMA) or other converter materials to create a frictional or form-fitting connection between components, allowing automatic engagement or disengagement based on thermal, magnetic, or electrodynamic energy changes without external control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external energy sources (hydraulic cylinders, electric coils) are used to activate brake or clutch devices, then reliable power transmission control is achieved, but device complexity increases

Engineering Contradiction:
Improvereliable power transmission controlVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The brake or clutch device activates automatically based on its own operational state (temperature, centrifugal force) without requiring external energy sources. The shape memory alloy elements or centrifugal masses self-regulate the friction connection based on predefined physical thresholds, eliminating the need for external actuators while maintaining reliable control

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical actuation systems (hydraulic cylinders, electric coils) with simpler physical mechanisms. Shape memory alloys substitute for hydraulic/electric actuators, and centrifugal masses substitute for mechanical linkages, reducing device complexity while preserving functional reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If mechanical actuators (brake shoes, linkages) are used for activation, then controlled braking or clutching is achieved, but energy consumption increases

Engineering Contradiction:
Improvecontrolled braking or clutchingVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The device uses its own operational parameters (temperature changes during braking, rotational speed) to automatically activate or deactivate the friction connection. Shape memory alloys respond to temperature changes caused by braking itself, and centrifugal masses respond to rotational speed, creating a self-regulating system that consumes no additional energy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the activation parameter from external energy input to intrinsic operational parameters. Temperature (via shape memory alloys) and rotational speed (via centrifugal masses) serve as activation triggers, allowing controlled operation without additional energy consumption

Inventive Principle:
Principle #35Parameter changes

3Extent of automation

If shape memory alloy or centrifugal mass mechanisms are used, then external energy supply is eliminated, but device complexity may increase in other aspects

Engineering Contradiction:
Improveautomatic engagement or disengagementVSAvoidstructural complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts the complex control system (hydraulic/electric actuators, sensors, control logic) and replaces it with simple passive physical mechanisms. Shape memory alloy elements and centrifugal masses are direct replacements that eliminate entire subsystems, reducing overall structural complexity despite the specialized materials used

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables simple, self-sufficient, and energy-efficient switching or coupling processes between components, reducing the need for external energy supplies and enhancing operational reliability in temperature-controlled environments.

Implementation Method 1

a wire or strip-shaped converter material, which is connected to the other two ends of the active surface element and which, when energy is input, preferably when energy is input without contact, undergoes a change in shape

Methodology Applied
Scientific EffectShape memory alloy: Shape Memory Alloy

Data Source

PatentEP1952040B1Apparatus for producing a frictional and/or form-fitting connection between two components which are arranged such that they can be moved linearly or rotated relative to one another
Publication Date: 2010.09.15 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP1952040B1 patent drawingFigure 1~2
  • EP1952040B1 patent drawingFigure 3~4
  • EP1952040B1 patent drawingFigure 5

AI summary

An apparatus is described for producing a frictional and/or form-fitting connection between two components which are arranged such that they can be moved linearly or rotated relative to one another, for the purpose of transmitting forces and/or force moments which act in a linear and/or rotational manner between the two components, of which the first component surrounds the second component at least in sections with at least one inner wall which faces the second component, and the second component provides at least one active-face element which can be transferred in a force-loaded manner from a first position, in which the active-face element is spaced apart from the inner wall, into a second position, in which the active-face element enters the frictional and/or form-fitting connection with the inner wall. The invention is distinguished by the fact that at least one mechanical stressing element is provided which deploys a restoring force on the active-face element, which restoring force holds the active-face element in the first position, and by the fact that a kinematic system is provided which acts on the active-face element counter to the restoring force, is driven exclusively by a converter material and transfers the active-face element into the second position.