Multi-stable Solenoid Intermediate Pole Piece Design
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Solution Overview
Problem
Conventional multi-stable solenoids require large volumes of permanent magnets, increasing costs and potentially leading to magnetic saturation issues due to the extensive radial extension of magnets over the solenoid volume.
Innovation Solution
Incorporating an intermediate pole piece that extends radially outward from the inner coil plane to reduce the required size of the permanent magnet, maintaining its axial length and preventing saturation, while allowing for efficient magnetic flux flow into the armature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional multi-stable solenoids use large volumes of permanent magnets extending radially, then the solenoid can achieve multi-stable positions, but the cost increases and magnetic saturation issues occur
Solution Approach 1:
The patent divides the magnetic circuit into multiple pole pieces (first pole piece, intermediate pole piece, and second pole piece) arranged axially. This segmentation allows the magnetic flux to be distributed through different paths, reducing the requirement for large radial extension of permanent magnets while maintaining multi-stable functionality.
Solution Approach 2:
The patent transitions from radial magnetic flux distribution to axial magnetic flux distribution by arranging pole pieces along the axial direction. The intermediate pole piece extends radially outwardly past the inner coil plane, creating a three-dimensional magnetic circuit that reduces permanent magnet volume requirements while maintaining stability.
2Force
If permanent magnets are extended radially over the solenoid volume, then magnetic flux can be generated, but magnetic saturation issues arise
Solution Approach 1:
The intermediate pole piece is positioned to extend radially outwardly past the inner coil plane, creating localized magnetic flux paths. This local quality enhancement allows concentrated flux generation at critical locations without requiring uniform radial extension of large permanent magnets, thereby avoiding saturation.
3Stability of the object's composition
If large permanent magnets are used, then stable positions are maintained, but cost increases
Solution Approach 1:
The magnetic circuit is segmented into multiple pole pieces that work together to maintain armature stability. This segmentation reduces the total volume of permanent magnet material required while distributing the stabilizing function across multiple components.
Solution Approach 2:
The intermediate pole piece acts as a mediator in the magnetic circuit, facilitating flux flow between the first and second pole pieces. This intermediary structure enables stable armature positioning with reduced permanent magnet volume by optimizing the magnetic path.
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 reduces the volume and cost of the permanent magnet, enhances armature stroke length, and decreases energy requirements by allowing the armature to remain in stable positions without continuous coil energization, while minimizing saturation and 'NI' losses.
Implementation Method 1
When a current is applied to the wire coil, a magnetic field is generated that can actuate (i.e., move) the moveable armature from one stable position to another
Implementation Method 2
a permanent magnet arranged adjacent to the intermediate pole piece
Data Source
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AI summary
A multi-stable solenoid includes a housing defining a first end and an opposing second end, a wire coil arranged within the housing and defining an inner coil plane defined along a radially innermost diameter of the wire coil, a first pole piece arranged adjacent to the first end of the housing, a second pole piece arranged adjacent to the second end of the housing, and an intermediate pole piece arranged axially between the first pole and the second pole. The intermediate pole piece extends radially outwardly past the inner coil plane to an outer surface. The solenoid further includes a permanent magnet arranged adjacent to the intermediate pole piece, and an armature slidably arranged within the housing and moveable between two or more stable positions. Selective energization of the wire coil is configured to move the armature between the two or more stable positions.