Rotary Reciprocating Actuator With Magnetic Reference Positioning

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Solution Overview

Problem

Conventional rotary reciprocating drive actuators face challenges in achieving high accuracy and assemblability, particularly when positioning and fixing a galvano mirror with its axis perpendicular to a product, which is essential for applications like laser processing apparatuses.

Innovation Solution

The proposed configuration includes a movable body with a magnet on a shaft, a base portion with bearing support for rotatable shaft, and a core assembly with magnetic poles and a coil to generate magnetic flux, along with a magnet position holding portion for precise positioning and fixation, utilizing a positioning fixation part to secure the assembly to a target object.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the beam scanner is fixed to a product with the mirror axis perpendicular to the product, then the assemblability is improved, but the positioning accuracy deteriorates

Engineering Contradiction:
ImproveassemblabilityVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The actuator is divided into separate functional modules: a base portion for mounting, a movable body for rotation, and a core assembly for driving. The positioning fixation part is integrated into the base portion, allowing the mounting function to be separated from the rotating function. This segmentation enables easy assembly while maintaining positioning accuracy through the dedicated positioning fixation part.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positioning fixation part includes positioning protrusions and positioning grooves that automatically align and fix the actuator to the product without requiring additional positioning operations. The magnet position holding portion generates magnetic attraction force to automatically hold the galvano mirror at the reference position, eliminating the need for manual positioning adjustments.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If the magnet position holding portion is added to define reference position, then the positioning accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The magnet position holding portion is integrated into the core assembly, merging the positioning function with the driving function. The positioning fixation part is incorporated into the base portion structure, combining mounting and positioning functions. This merging approach improves positioning accuracy without significantly increasing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnet position holding portion uses magnetic attraction force instead of mechanical contacts or additional fastening mechanisms to define and hold the reference position. This substitution reduces mechanical complexity while achieving precise positioning, as the magnetic field provides both the holding force and the positioning reference without physical interference.

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

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

This configuration enables high-accuracy and high-assemblability positioning and fixation of the rotary reciprocating drive actuator, ensuring precise rotational control and stability, suitable for applications such as LiDAR and optical scanning systems.

Implementation Method 1

a coil body that is wound around the core body and that is energized to generate a magnetic flux interacting with the magnet to cause a reciprocating rotation of the movable body

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Implementation Method 2

a magnet position holding portion that generates a magnetic attraction force between the magnet position holding portion and the magnet to define a reference position of the reciprocating rotation

Methodology Applied
Scientific EffectMagnetic attraction force: Magnetism

Data Source

PatentEP4307528A1Rotary reciprocating drive actuator
Publication Date: 2024.01.17 MITSUMI ELECTRIC CO LTD
  • EP4307528A1 patent drawingFigure 1
  • EP4307528A1 patent drawingFigure 2
  • EP4307528A1 patent drawingFigure 3

AI summary

A rotary reciprocating drive actuator includes: a movable body (10) including a shaft part (13) to which a magnet (32) is fixed at an outer circumference of the shaft part (13), the movable body (10) being capable of performing a reciprocating rotation about an axis; a base portion (21) including a pair of wall portions (211, 212) for supporting the shaft part (13) via a bearing (22) such that the shaft part (13) is rotatable; and a core assembly (40) including: a core body (400) including a plurality of magnetic poles (410a, 410b) facing an outer circumference of the magnet (32) to sandwich the magnet (32), a coil body (49) that is wound around the core body (400) and that is energized to generate a magnetic flux interacting with the magnet (32) to cause a reciprocating rotation of the movable body (10), and a magnet position holding portion (48) that generates a magnetic attraction force between the magnet position holding portion (48) and the magnet (32) to define a reference position of the reciprocating rotation, the core assembly (40) being fixed to one wall portion (211) of the pair of wall portions (211, 212), in which at least one of the base portion (21), the core body (400), or the core assembly (40) includes a positioning fixation part (215) for positioning and fixing the at least one of the base portion (21), the core body (400), or the core assembly (40) to a fixation target object (800) in a direction parallel to the shaft part (13).