Torque Sensor Index Magnet Carrier Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensor arrangements for motor vehicles, particularly in steering systems, are not compact or cost-effective, as they combine torque sensors with magnetic measuring principles and rotation angle index units, often requiring complex magnetic circuit designs and additional components.
Innovation Solution
A compact and cost-effective sensor arrangement integrating a torque sensor with a magnetic measuring principle and a rotation angle index unit, utilizing a stator pack with overmoulded stator elements, a magnetically conductive carrier, and a permanent index magnet with elastic connecting elements, which shields and decouples the magnetic circuits, allowing for robust and flexible detection of steering torque and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a torque sensor with magnetic measuring principle and rotation angle index unit are combined, then the sensor arrangement can measure steering torque and rotation, but the device becomes complex and expensive
Solution Approach 1:
The patent combines the torque sensor and rotation angle index unit into a single integrated sensor arrangement. The stator pack serves both torque measurement and rotation detection functions, while the index magnet is integrated with the rotor assembly. This merging eliminates the need for separate sensors and reduces overall device complexity despite maintaining dual measurement capabilities.
Solution Approach 2:
The stator pack is designed to perform multiple functions: it serves as the magnetic circuit for torque measurement and simultaneously provides the reference structure for rotation angle detection. The index magnet serves dual purposes by providing both the magnetic field for rotation detection and the reference position for the index sensor. This multi-functionality reduces the number of components needed.
2Measurement precision
If additional components and complex magnetic circuit designs are used, then measurement accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple functions into fewer components, reducing the total part count and assembly steps. The integrated stator pack and rotor assembly eliminate the need for separate torque sensors and rotation encoders, simplifying manufacturing while maintaining measurement precision through the magnetic measuring principle.
Solution Approach 2:
The index magnet serves itself by providing the magnetic field that is detected by the index sensor, eliminating the need for separate excitation sources. The magnetic circuit elements serve dual purposes in both torque measurement and rotation detection, reducing the need for additional components that would increase manufacturing cost.
3Reliability
If the magnetic circuits of torque sensor and rotation angle index unit are separated, then measurement reliability is improved, but device compactness is reduced
Solution Approach 1:
The patent segments the magnetic circuits into distinct torque measurement and rotation detection paths within the integrated structure. The stator pack contains separate magnetic circuit elements for torque measurement, while the index magnet and index sensor provide a separate magnetic path for rotation detection. This segmentation prevents magnetic field interference while maintaining a compact integrated design.
Solution Approach 2:
The index magnet acts as an intermediary that provides a reference magnetic field for the index sensor while being part of the rotor assembly. This intermediary element enables the rotation detection function without interfering with the torque measurement magnetic circuit, allowing both functions to coexist in a compact integrated structure with improved reliability.
4Volume of moving object
If a compact design is implemented, then device size is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent merges the torque sensor and rotation angle index unit into a single compact assembly where the stator pack and rotor assembly are integrated. The index magnet is directly mounted on the rotor, and the index sensor is positioned within the stator pack, eliminating the need for separate housings and mounting structures, thus reducing device size while maintaining manufacturability.
Solution Approach 2:
The stator pack is designed as a multi-functional component that serves both torque measurement and rotation detection functions. This universal design reduces the number of separate components needed, simplifying the overall integration process while achieving a compact form factor. The magnetic circuit elements are designed to fulfill multiple roles, reducing integration complexity.
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 a compact, inexpensive, and robust sensor arrangement capable of accurately measuring steering torque and rotation within a defined range, maintaining reliability across varying air gaps and temperature fluctuations, while simplifying manufacturing processes.
Implementation Method 1
a permanent index magnet (11) for generating a basic position signal for determining a basic position of the shaft (2, 3)
Implementation Method 2
The carrier made of magnetically conductive material serves to shield or decouple the magnetic circuits of the torque sensor and the rotation angle index unit from one another or to largely shield or separate or decouple the magnetic circuit of the torque sensor from the magnetic field of the index magnet
Implementation Method 3
The first and second shaft sections are preferably connected to one another by means of a torsion bar
Implementation Method 4
The stator pack preferably comprises at least two stator elements which are at least partially overmoulded together
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a sensor arrangement comprising a torque sensor (1) for sensing the torque acting on a shaft, wherein the shaft of the torque sensor comprises two shaft segments (2, 3), wherein a magnetic encoder (4) is disposed on the first shaft segment (2) and a stator packet (5) is disposed on the second shaft segment (3), said stator packet having at least two magnetically conductive stator elements (6) conducting the magnetic field generated by the magnetic encoder (4) of the first shaft segment (2) and guiding said field directly or indirectly to one or more magnetic field sensor elements (7) for sensing the torque, and comprising an angle of rotation index unit (10) designed to be able to detect and/or identify the angular position of the shaft (2, 3) with respect to a defined angle of rotation and/or a defined range of angle of rotation, wherein the angle of rotation index unit (10) comprises an index magnet (11) that is attached to a carrier (12), wherein the carrier (12) is connected to the magnetic encoder (4) or at least to one of the stator elements (6).