Wiegand Rotation Sensor With Inclined Multi-Pole Magnet Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotation detection devices using magnetic wires with a large Barkhausen effect face challenges in achieving a simple, small, and efficient structure due to complex assembly requirements and non-uniform magnetic field application, leading to reduced output and increased size.
Innovation Solution
A rotation detection device utilizing a ring-shaped multi-pole magnet with an inclined magnetization pattern and magnetic flux conducting pieces to ensure uniform magnetic field application to the magnetic wire, allowing for a simple and compact design with high-output signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a complex magnetic field application structure is used to ensure uniform magnetic field distribution, then the output signal quality improves, but the device size and assembly complexity increase
Solution Approach 1:
The magnetic wire is divided into multiple sections along its length, with each section experiencing controlled magnetization reversal. This segmentation allows the uniform magnetic field to effectively reverse magnetization throughout the entire wire length, improving pulse signal quality without requiring complex field distribution structures
Solution Approach 2:
The invention changes the magnetic field application parameters by using a simplified single-direction magnetic field that is uniformly distributed along the wire length. By optimizing the field strength and duration parameters, the system achieves effective magnetization reversal without complex structural arrangements
2Power
If the magnetic wire length is increased to maximize power output, then the available electric power increases, but the device size increases
Solution Approach 1:
The magnetic wire is segmented into multiple sections that can be arranged in a compact configuration. This allows the total wire length to be extended for higher power output while maintaining a small device footprint through efficient spatial arrangement of the segmented sections
Solution Approach 2:
The magnetic wire is arranged in a three-dimensional configuration rather than a simple linear extension. By folding or coiling the wire in additional spatial dimensions, the effective length is increased for higher power output without proportionally increasing the device's external dimensions
3Device complexity
If a simplified magnetic field application method is used, then the device structure becomes simpler and smaller, but the uniformity of magnetic field distribution deteriorates
Solution Approach 1:
The magnetic field application is optimized for the local conditions along the magnetic wire. By positioning the magnetic field source to create a uniformly distributed field along the wire length, the system achieves effective magnetization reversal with a simple structure, as the local field quality is sufficient for the intended function
Solution Approach 2:
The simplified magnetic field application structure serves multiple functions: it provides uniform field distribution along the wire length, enables effective magnetization reversal, and maintains compact device size. This multi-functional design eliminates the need for complex specialized structures
4Measurement precision
If complex assembly procedures are used to achieve optimal magnetic field alignment, then the detection precision improves, but the ease of manufacture decreases
Solution Approach 1:
The magnetic wire is positioned asymmetrically relative to the magnetic field source in a specific optimized configuration. This asymmetric arrangement naturally produces the required magnetic field distribution and magnetization reversal pattern, eliminating the need for complex alignment procedures while maintaining detection precision
Solution Approach 2:
The magnetic wire is pre-positioned in the optimal location during manufacturing, and the magnetic field source is configured to naturally produce the required field distribution. This preliminary arrangement ensures that no complex alignment or adjustment procedures are needed during assembly, as the optimal configuration is built-in from the start
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 device achieves a high-output signal with a small size by efficiently applying a uniform magnetic field to the magnetic wire, simplifying assembly and reducing complexity while maintaining effective rotation detection.
Implementation Method 1
Magnetic wires having a large Barkhausen effect (large Barkhausen jump) are known in the name of Wiegand wire or pulse wire... When the external magnetic field strength is increased to a certain magnetic field strength, the magnetization direction of the soft layer is reversed. The reversal of the magnetization direction starts at a certain position of the magnetic wire to propagate to the entire wire, whereby the magnetization direction of the soft layer is totally reversed. At this time, the large Barkhausen effect is exhibited to induce a pulse signal in the coil wound around the magnetic wire.
Implementation Method 2
A power generation sensor is produced by winding a coil around the magnetic wire... When the external magnetic field strength is increased to a certain magnetic field strength, the magnetization direction of the soft layer is reversed. The reversal of the magnetization direction starts at a certain position of the magnetic wire to propagate to the entire wire, whereby the magnetization direction of the soft layer is totally reversed. At this time, the large Barkhausen effect is exhibited to induce a pulse signal in the coil wound around the magnetic wire.
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3C
AI summary
A rotation detection device includes a ring-shaped multi-pole magnet provided on a rotation shaft, and a power generation sensor to detect a magnetic field which changes according to rotation of the multi-pole magnet. The power generation sensor includes a magnetic wire configured to exhibit a large Barkhausen effect, a coil wound around the magnetic wire, and a pair of magnetic flux conducting pieces made of magnetically-soft components respectively magnetically coupled to both end portions of the magnetic wire. The ring-shaped multi-pole magnet has a magnetization pattern on an outer circumferential portion, the magnetization pattern being inclined with respect to the rotation shaft. The power generation sensor faces the magnetization pattern of the multi-pole magnet in a posture in which an axial direction of the magnetic wire is parallel to the rotation shaft.