Magnetic Position Sensor Package with Non-Magnetic Bearing
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Solution Overview
Problem
Existing position sensing technologies face challenges in accurately measuring the position of movable objects over large strokes with high precision, particularly due to interference from external magnetic disturbances and assembly tolerances.
Innovation Solution
A magnetic position sensing system utilizing a rotating magnet and a magnetic field sensor, where the movable object affects the magnet's rotation, allowing the sensor to detect changes in the magnetic field, which are then used to compute the object's position. This system includes a non-magnetic bearing, various sensor arrangements, and optional shielding to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional position sensing technologies are used, then measurement precision is maintained for small ranges, but measurement accuracy deteriorates for large stroke measurements due to external magnetic disturbances
Solution Approach 1:
The patent introduces a non-magnetic bearing as an intermediary component that supports the magnet while being immune to magnetic disturbances. This mediator allows the magnet to rotate freely without being affected by external magnetic fields, thereby maintaining measurement accuracy in large stroke applications where traditional sensors fail due to magnetic interference.
Solution Approach 2:
The patent replaces traditional mechanical position sensing systems with a magnetic field-based sensing system. By using a magnetic field sensor to detect the position of a magnet rather than mechanical encoders or potentiometers, the system achieves larger measurement ranges without being susceptible to mechanical wear or magnetic disturbances that affect conventional systems.
2Measurement precision
If high precision position sensing is implemented, then measurement accuracy improves, but device complexity and cost increase
Solution Approach 1:
The patent divides the position sensing function into two separate components: a simple magnet attached to the moving object and a magnetic field sensor mounted on the sensor board. This segmentation allows each component to be inexpensive and simple, while their combination provides high-precision position measurement, avoiding the need for complex integrated sensors.
Solution Approach 2:
The magnet serves its own function of generating the magnetic field for sensing while being passively affected by the movable object's position. The system uses the natural magnetic properties of the magnet without requiring additional power or complex control mechanisms, thereby reducing device complexity while maintaining measurement precision.
3Ease of manufacture
If assembly tolerances are relaxed to reduce manufacturing cost, then ease of manufacture improves, but measurement precision deteriorates
Solution Approach 1:
The patent replaces mechanical coupling mechanisms with magnetic field interaction. The magnet and magnetic field sensor communicate through the magnetic field without physical contact, eliminating the need for precise mechanical alignment. This substitution allows for relaxed assembly tolerances while maintaining measurement precision, as the magnetic field can penetrate non-magnetic materials and does not require direct contact.
4Length of stationary object
If a rotating magnet mechanism is used to achieve large stroke measurement, then measurement range increases, but reliability deteriorates due to potential mechanical failures
Solution Approach 1:
The patent replaces mechanical position encoding mechanisms with a magnetic field sensing system. The magnet rotates or moves with the movable object, and its position is detected by the magnetic field sensor without mechanical contact. This eliminates wear, friction, and mechanical failure modes, thereby maintaining reliability while achieving large measurement ranges.
Solution Approach 2:
The magnetic field acts as an intermediary between the magnet and the sensor, allowing position detection without direct mechanical contact. The non-magnetic bearing serves as another intermediary that supports the magnet's rotation while being immune to magnetic forces, thereby reducing mechanical stress and improving reliability of the rotating mechanism.
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 system provides improved measurement accuracy and cost-effectiveness for large stroke measurements while minimizing errors from external magnetic disturbances and assembly tolerances.
Implementation Method 1
the magnetic field sensor is arranged to detect a magnetic field of the magnet
Implementation Method 2
the object is movable in the vicinity of the magnet to affect the rotation of the magnet
Data Source
AI summary
A device for detecting an object is suggested comprising a magnetic field sensor, a magnet that is arranged to rotate in a vicinity of the magnetic field sensor, wherein the object is movable in the vicinity of the magnet to affect the rotation of the magnet, wherein the magnetic field sensor is arranged to detect a magnetic field of the magnet. Also, a system comprising such device is provided.