Torque Sensor Magnetic Shielding for EPS Interference
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Solution Overview
Problem
Existing torque sensors in electronic power steering systems are affected by external magnetic fields, leading to inaccurate torque measurements due to magnetic flux interference, especially in vehicles with multiple electronic components.
Innovation Solution
A sensing device with a stator and rotor configuration where a magnet is rotatably disposed between stator teeth, and collectors are positioned between the teeth to prevent external magnetic field interference, using a unique arrangement of stator and rotor teeth and magnets to minimize magnetic field leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the collector is disposed at an outer side of the stator tooth, then the structure is simplified, but the torque sensor is affected by external magnetic fields
Solution Approach 1:
The patent introduces a magnetic shield (intermediary element) between the external magnetic field source and the collector to block or attenuate the external magnetic field. This shield acts as a mediator that protects the sensitive collector from external magnetic interference while allowing the sensor to continue functioning with simplified structure.
2Ease of manufacture
If the collector is disposed at an outer side of the stator tooth, then manufacturing is easier, but magnetic flux value is affected by external magnetic fields
Solution Approach 1:
A magnetic shield is introduced as an intermediary component that can be easily integrated into the existing sensor structure. This shield blocks external magnetic fields from reaching the collector, thereby protecting the magnetic flux measurement precision while maintaining the ease of manufacture associated with the outer-side collector configuration.
3Adaptability or versatility
If multiple chips are mounted in a vehicle, then functionality is enhanced, but the likelihood of torque sensor being affected by external magnetic field increases
Solution Approach 1:
The magnetic shield serves as a protective intermediary that isolates the torque sensor from external magnetic fields generated by multiple electronic chips. This allows the vehicle to maintain enhanced functionality with multiple chips while the shield prevents these chips from creating harmful magnetic interference with the sensor.
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 effectively prevents or minimizes magnetic field interference, allowing for accurate torque measurement by ensuring the collectors and sensor are shielded from external magnetic fields, thereby enhancing the reliability of torque sensing in electronic power steering systems.
Implementation Method 1
a magnet coupled to the rotor body... each of the first region and the second region includes an N-pole region and an S-pole region
Implementation Method 2
a collector to measure the torque... a magnetic flux value of a Hall integrated circuit (IC) is affected
Data Source
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AI summary
An embodiment relates to a sensing device comprising: a stator; and a rotor, at least a part of which is arranged on the stator. The stator comprises a stator holder, a stator body coupled to the stator holder, and a first stator tooth and a second stator tooth arranged on the stator body. The rotor comprises a rotor holder, a rotor body coupled to the rotor holder, and a magnet coupled to the rotor body. The first stator tooth comprises a first body and multiple first teeth connected to the first body and spaced apart from each other. The second stator tooth comprises a second body and multiple second teeth connected to the second body and spaced apart from each other. The multiple first teeth and the multiple second teeth overlap in the radial direction. Accordingly, the sensing device can prevent or minimize magnetic-field interference resulting from an external magnetic field generated outside during torque measurement.