Capacitive Actuator Motor Buckling Mechanism

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Solution Overview

Problem

Existing multi-pair buckling actuators can only generate thrust when the output portion is pressed against a rail, limiting the effective use of energy output by piezoelectric elements.

Innovation Solution

A capacitive actuator motor with a plurality of actuator units, each featuring a buckling displacement expansion mechanism and an output transmission portion that maintains contact with a periodic shape portion of an output cam, utilizing a spring preload adjustment mechanism to ensure constant urging force and effective energy transmission regardless of displacement or voltage application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the output portion is pressed against the rail to generate thrust, then thrust can be generated, but energy from the piezoelectric element cannot be fully utilized when the output portion is away from the rail

Engineering Contradiction:
Improveenergy utilization of piezoelectric elementVSAvoidthrust generation reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces a spring mechanism that dynamically adjusts the contact force between the output portion and the periodic shape portion of the cam. The spring allows the system to maintain reliable thrust generation while accommodating dynamic displacement variations, enabling full utilization of piezoelectric element energy across different operating states.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring acts as an intermediary element between the output portion and the periodic shape portion, ensuring continuous contact and force transmission. This intermediary mechanism guarantees that energy from the piezoelectric element is effectively transmitted to generate thrust regardless of the output portion's position.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the output portion is always in contact with the rail, then thrust can be continuously generated, but the system cannot accommodate displacement variations of the expandable element

Engineering Contradiction:
Improvecontinuous thrust generationVSAvoiddisplacement accommodation capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The spring mechanism provides dynamic adaptability, allowing the output portion to maintain contact with the periodic shape portion while accommodating displacement variations of the expandable element. This dynamic system ensures continuous thrust generation without compromising adaptability to different displacement states.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the urging force is not always positive, then the structure is simpler, but the output transmission portion cannot be reliably pressed against the periodic shape portion

Engineering Contradiction:
Improveurging mechanism complexityVSAvoidcontact maintenance reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The spring is pre-loaded to generate a positive urging force that continuously presses the output transmission portion against the periodic shape portion. This preliminary action ensures reliable contact maintenance without requiring complex active control mechanisms, achieving reliability through simple pre-loaded elastic deformation.

Inventive Principle:
Principle #10Preliminary action

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 the capacitive actuator motor to efficiently utilize energy from expandable elements with capacitive properties, ensuring consistent thrust generation and energy transmission across various displacements and voltage conditions.

Implementation Method 1

an expandable element that has capacitive properties

Methodology Applied
Scientific EffectCapacitive properties: Capacitance

Implementation Method 2

a displacement expansion mechanism that converts displacement of the expandable element into an expanding displacement in a predetermined direction by generating a buckling phenomenon

Methodology Applied
Scientific EffectBuckling phenomenon:

Implementation Method 3

urging means configured to always generate an urging force such that the periodic shape portion and the output transmission portion come into contact with each other

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3273591B1Capacitive actuator motor
Publication Date: 2023.04.19 SUMITOMO HEAVY IND LTD
  • EP3273591B1 patent drawingFigure 1A~1B
  • EP3273591B1 patent drawingFigure 1C~2A
  • EP3273591B1 patent drawingFigure 2B~3A

AI summary

A capacitive actuator motor (100) according to an embodiment of the present invention includes a capacitive actuator (1) having six actuator units (11) and a motor output cam (2) having a periodic shape portion (20). Each of the six actuator units (11) includes a buckling displacement expansion mechanism (11a) configured to convert an output of a piezoelectric element (11a1) and urge an output joint (11b) in a predetermined output direction and a preload adjustment spring (11a4) configured to urge an output joint (11b) with a certain characteristic in a direction in which the periodic shape portion (20) and the output joint (11b) come into contact with each other.