Electromagnetic Actuator with Segmented Armature for Wear and Magnetic Efficiency
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Solution Overview
Problem
Electromagnetic actuating devices face issues with wear and tear in the engagement area due to the limited hardness of soft-magnetic metal materials and magnetic inefficiencies caused by permanent magnet short-circuits in internal combustion engine applications, necessitating improvements in both long-term operation and magnetic efficiency.
Innovation Solution
The actuating element is designed with two sections: a magnetically non-conductive austenitic steel section for the permanent magnet area to prevent magnetic shunts and a hardened martensitic steel section for increased wear resistance in the engagement area, connected through friction welding for enhanced properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If soft-magnetic metal material is used for the actuating element, then magnetic conductivity is improved, but wear resistance in the engagement area deteriorates
Solution Approach 1:
The actuating element is divided into two distinct sections: a first section with soft-magnetic metal material for optimal magnetic conductivity in the permanent magnet area, and a second section with hardened material for enhanced wear resistance in the engagement area. This segmentation allows each section to be optimized for its specific functional requirements without compromising the other.
Solution Approach 2:
Different material properties are applied to different regions of the actuating element. The first section uses soft-magnetic metal material with high magnetic conductivity, while the second section uses hardened material with superior wear resistance. This local differentiation of material quality ensures that each area of the actuating element has the precise properties needed for its specific function.
2Device complexity
If permanent magnet means are designed with axial magnetization parallel to the actuating element axis, then compact design is improved, but magnetic efficiency deteriorates due to short-circuiting
Solution Approach 1:
The problematic soft-magnetic material that causes magnetic short-circuiting is removed from the first section of the actuating element. By using non-soft-magnetic material in this region, the permanent magnetic field is no longer shunted, allowing the permanently magnetized actuating element to interact effectively with the stationary core area while maintaining compact axial design.
Solution Approach 2:
The magnetic conductivity parameter of the actuating element material is changed in the first section to be non-soft-magnetic, which prevents magnetic field short-circuiting. This parameter change allows the permanent magnet to maintain its magnetic efficiency while the element remains compact with axial magnetization.
3Reliability
If hardening process is applied to increase wear resistance, then service life is improved, but magnetic conductivity deteriorates
Solution Approach 1:
The actuating element is segmented into two sections with different material treatments: the first section uses soft-magnetic metal material that maintains high magnetic conductivity, while the second section undergoes hardening process to achieve superior wear resistance. This segmentation resolves the contradiction by applying hardening only where wear resistance is critical, not where magnetic conductivity is essential.
Solution Approach 2:
Hardening treatment is applied locally only to the second section (engagement area) of the actuating element, while the first section retains soft-magnetic properties. This localized application of hardening ensures that wear resistance is enhanced in the engagement area without compromising the magnetic conductivity required in the permanent magnet area.
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 design significantly improves the actuating device's magnetic efficiency and wear resistance, extending its service life and operational effectiveness while maintaining manufacturability for large-scale production.
Implementation Method 1
a permanently magnetized actuating element, with a permanent magnet arrangement interacting with a stationary core area, in response to energization of a coil unit surrounding the actuating element, the latter moving along an axial direction relative to the core area
Implementation Method 2
in response to energization of a coil unit surrounding the actuating element
Implementation Method 3
the first and the second actuating element part being joined together by means of a friction welding process
Data Source
Figure 1~3
AI summary
The invention relates to an electromagnetic actuating device with an elongated actuating element as an armature, forming an engagement area at its end and movable by force of a stationary coil assembly, which has permanent magnet means magnetized section by section and axially along a direction of extension of the actuating element, which are designed to interact with a stationary core area, wherein the actuating element has two sections (16, 18), of which a first section (16), associated with the permanent magnet means, is configured with respect to magnetic conductivity such that no magnetic shunting and/or short-circuiting of the permanent magnet means occurs, and a second section (18), associated with the engagement area, has high wear resistance.