Magnetic Micro-Actuator Without Return Springs for Fast Reset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solenoid actuators are poorly suited for micro-mechanics, particularly in watchmaking, due to size constraints and the need for rapid actuation and return times, with the use of return springs limiting performance and complicating miniaturization.
Innovation Solution
A magnetic micro-actuator with a linear solenoid design that uses a permanent magnet and a ferromagnetic restoration element, such as a soft ferromagnetic ring, to provide a controlled mechanical braking force without mechanical springs, allowing for rapid actuation and return without the need for additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional solenoid actuators are used with return springs, then the actuator can achieve rapid return to rest position, but the size increases and durability is compromised
Solution Approach 1:
The patent replaces the mechanical return spring system with a magnetic field-based restoration mechanism. A ferromagnetic element is attracted back to the coil assembly by magnetic forces when the coil is de-energized, eliminating the need for mechanical springs and enabling rapid return without increasing actuator size.
Solution Approach 2:
The patent changes the physical state and properties of materials used - specifically using ferromagnetic materials that can be rapidly magnetized and demagnetized. This allows the restoration force to be activated and deactivated electrically, enabling precise control of return timing without mechanical complexity.
2Volume of moving object
If the actuator dimensions are reduced for watchmaking applications, then the device fits size constraints, but the actuation and return times increase
Solution Approach 1:
By replacing mechanical springs with magnetic field interactions, the system achieves rapid response times even in miniaturized form. Magnetic fields can be established and collapsed almost instantaneously, providing fast actuation and return cycles despite the small scale required for watchmaking applications.
Solution Approach 2:
The patent employs periodic electrical energization and de-energization of the coil to achieve repeated actuation and return cycles. This electrical periodic control allows precise timing of each stroke and return, maintaining rapid cycle times even as the actuator is miniaturized for compact applications.
3Reliability
If return springs are used in micro-actuators, then the actuator can achieve mechanical restoration, but the device complexity and component count increase
Solution Approach 1:
The patent merges the restoration function into the existing coil assembly by using a ferromagnetic element that is naturally attracted to the coil structure. This integration eliminates separate return spring components and simplifies the overall device architecture while maintaining reliable mechanical restoration.
Solution Approach 2:
The ferromagnetic element automatically returns to its rest position through magnetic attraction when the coil is de-energized, without requiring separate mechanical springs or complex restoration mechanisms. The magnetic field itself provides the self-restoring force, reducing component count and simplifying the device.
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
The magnetic micro-actuator achieves rapid and controlled movement with minimal components, ensuring precise actuation and return within small dimensions, suitable for applications requiring short reaction and return times, like watchmaking, and can be integrated into compact devices like watches.
Implementation Method 1
at least one coil (6, 61, 62), arranged to exert, in a powered position, an axial thrust force on a slide (30)
Implementation Method 2
The slide (30) comprises at least one permanent magnet (2) which generates a magnetic field of revolution around the axial direction (D)
Implementation Method 3
arranged to cooperate by magnetic attraction with at least one first ferromagnetic restoration element (8) to return the slide (30) to a rear end position
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
A magnetic micro-actuator (100) comprising a coil (6; 61; 62) controlling the axial displacement of a slide (30) comprising at least one permanent magnet (2) joined or aligned with a ferromagnetic or magnetized rear shaft (42) and guiding the field lines of the magnetic field of revolution along the axial direction (D) through the coil (6; 61; 62) in which the slide (30) travels, to a rear end (43) of said rear shaft (42) which tends to cooperate by magnetic attraction with at least one first ferromagnetic restoration element (8), located in the vicinity of a rear face (25) of the structure (20) of the micro-actuator (100), to return said slide (30) to a rear end position when no coil (6; 61; 62) is energized.