Magnetostrictive Torque Sensor Using Transverse Magnetic Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque sensors face performance degradation due to electrical and magnetic interference, temperature fluctuations, and manufacturing variability, particularly in applications requiring high accuracy and stability across varying temperatures.
Innovation Solution
A magnetostrictive torque sensor system utilizing a drive coil and sense coils mounted on a substrate, emitting a magnetic field transverse to the shaft, which improves temperature stability and manufacturing consistency, allowing for accurate torque measurement without a ferromagnetic core, and using commercial off-the-shelf micro-coils for cost-effectiveness and optimized performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a ferromagnetic core is used in conventional torque sensors, then the sensor can detect torque, but temperature stability deteriorates and manufacturing variability increases
Solution Approach 1:
The patent removes the ferromagnetic core from the torque sensor design, using only air-core coils mounted on the shaft surface. This extraction eliminates the temperature-dependent magnetic properties of ferrite materials while maintaining torque detection capability through magnetostrictive effects in the shaft itself.
Solution Approach 2:
The patent replaces the conventional ferromagnetic core-based magnetic field generation with a direct magnetostrictive measurement approach. The drive coil generates a magnetic field that induces magnetostrictive strain in the shaft, which is then detected by sense coils, eliminating the need for ferrite cores and their associated temperature stability issues.
2Measurement precision
If a ferromagnetic core is used in conventional torque sensors, then the sensor can detect torque, but manufacturing variability increases
Solution Approach 1:
By removing the ferromagnetic core component entirely, the patent eliminates the complex manufacturing processes required to produce consistent ferrite core geometries and magnetic properties, thereby reducing manufacturing variability.
Solution Approach 2:
The shaft itself serves multiple functions: it is both the mechanical component being measured and the magnetostrictive element that generates the detection signal. This eliminates the need for separate core components and reduces manufacturing complexity.
3Stability of the object's composition
If transverse magnetic field measurement is implemented, then temperature stability improves, but device complexity increases
Solution Approach 1:
The sensor is divided into functionally independent SMD coils mounted on the shaft surface. Each coil performs a specific function (drive or sense), and the modular SMD construction allows for simplified assembly and reduced overall structural complexity despite the transverse field configuration.
4Ease of manufacture
If conventional ferrite-core sensors are used, then manufacturing is simpler, but signal strength decreases due to interference
Solution Approach 1:
The patent replaces the ferrite-core magnetic amplification mechanism with a magnetostrictive detection mechanism using air-core SMD coils. The drive coil generates a magnetic field that directly induces magnetostrictive strain in the shaft, which is detected by sense coils, providing sufficient signal strength without the interference problems of ferrite cores.
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 solution provides improved temperature stability, reduced manufacturing variability, and enhanced accuracy in torque measurement, leading to better engine control and robustness against interference factors like cable vibrations and electromagnetic interference.
Implementation Method 1
a drive coil operative to receive a drive current and to emit a magnetic field through the drive shaft
Implementation Method 2
a magnetostrictive sensor having a sensor probe comprising... the magnetic field is emitted from the drive coil in a transverse direction to a radius of the drive shaft
Data Source
AI summary
According to some embodiments, system and methods are provided, comprising an installed product including a drive shaft; a magnetostrictive sensor having a sensor probe comprising: a substrate; a drive coil operative to receive a drive current and to emit a magnetic field through the drive shaft, wherein the drive coil is mounted on the substrate; one or more sense coils operative to receive the magnetic field and to transmit a signal based on the received magnetic field, wherein the one or more sense coils are mounted on the substrate; and wherein the magnetic field is emitted from the drive coil in a transverse direction to a radius of the drive shaft. Numerous other aspects are provided.