Structured Pole Shoes for Electromagnetic Actuator Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic actuators for surgical or medical instruments face issues with maintaining optimal optical system focus and stroke distance due to manufacturing and assembly inaccuracies, leading to deviations in image quality and complex stroke setting processes.
Innovation Solution
The electromagnetic actuator features structured annular pole shoes on the stator and movable element, ensuring a fixed angular relationship through corresponding circumferential structures, which minimizes gap and maintains optimal alignment, eliminating rotational deviations and allowing reproducible stroke distances without mechanical guides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional electromagnetic actuators are used without structured pole shoes, then the actuator can move the movable element, but manufacturing and assembly inaccuracies cause rotational deviations that lead to optical system focus errors and image quality degradation
Solution Approach 1:
The pole shoes are equipped with circumferential structures (teeth, ridges, or protrusions) that create localized magnetic flux paths. These structures are positioned at specific locations on the pole shoe surfaces to generate targeted alignment forces that counteract rotational deviations caused by manufacturing inaccuracies, thereby maintaining optical focus without requiring overall structural complexity
Solution Approach 2:
Instead of using mechanical guides or alignment mechanisms to prevent rotational deviations, the patent employs magnetic field interactions through structured pole shoes. The magnetic flux lines follow the structured surfaces to create self-aligning forces, replacing mechanical alignment systems with electromagnetic field-based alignment
2Manufacturing precision
If stop surfaces are used to define stroke distance, then the actuator stroke can be limited, but manufacturing and assembly inaccuracies cause the actual stroke to deviate from the intended stroke
Solution Approach 1:
The structured pole shoes on both stator and movable element create self-aligning magnetic forces that automatically compensate for stroke distance deviations. The magnetic flux lines follow the structured surfaces to generate forces that maintain the intended stroke distance without requiring complex adjustment mechanisms or precision manufacturing of stop surfaces
3Manufacturing precision
If the traveller is freely rotatable, then the actuator can accommodate misalignments, but rotational movement causes the optical system to deviate from optimal focus
Solution Approach 1:
The structured pole shoes change the magnetic field distribution parameters to create directional alignment forces. The circumferential structures modify the magnetic flux density and direction, generating torques that actively counteract rotational movement and maintain the optical system in optimal focus while allowing the traveller to remain rotatable
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 solution stabilizes the rotational position of the actuator, maintaining image quality and ensuring consistent stroke distances despite assembly inaccuracies, simplifying the setting process and reducing friction.
Implementation Method 1
can be reversibly moved from a first position to a second position by the application of a switchable magnetic field
Implementation Method 2
electromagnetic actuator for a surgical or medical instrument
Implementation Method 3
the movable element is held in the first or the second position by a permanent magnetic field
Implementation Method 4
The magnetic flux lines seek the path of least resistance, which leads to the fact that the protruding, thus, projecting regions of the structured surfaces of the pole shoes are aligned to each other as precisely as possible
Data Source
AI summary
An electromagnetic actuator for a medical instrument including: a stator; and a movable element, at least partly composed of a paramagnetic and/or a ferromagnetic material, and which can be reversibly moved from a first to a second position by the application of a switchable magnetic field, wherein the stator and the movable element have annular distal and proximal pole shoes corresponding to each other, wherein the distal pole shoes and/or the proximal pole shoes of the stator and the movable element are aligned with each other in an overlapping manner in the first and/or the second position, and the distal pole shoes and/or the proximal pole shoes of the stator and the movable element have a structure in the circumferential direction on the surfaces of pole shoes facing each other, with the structures corresponding to each other.