Variable Reluctance Magnetic Sensor for Valve Position
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensors for detecting the rotational position of valves in industries like aerospace face reliability issues due to mechanical contact, which can lead to reduced accuracy and durability.
Innovation Solution
A variable reluctance magnetic sensor system comprising a rotor, stator, and magnetic sensors, where the rotor and stator are made of magnetically permeable materials, and a magnet is used to detect rotational positions without mechanical contact, utilizing magnetic flux to generate position signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical switches are used to sense valve position, then the sensor can detect rotational position, but the reliability decreases due to repeated mechanical contact
Solution Approach 1:
The patent replaces the mechanical switch system with a magnetic field-based sensing system. Magnets are mounted on the valve shaft, and magnetic sensors (such as Hall effect sensors or reed switches) are positioned in the housing to detect changes in magnetic field as the valve rotates. This substitution eliminates all mechanical contact between the sensing mechanism and the moving valve components, thereby eliminating wear and significantly improving reliability while maintaining the ability to detect valve position.
2Duration of action of stationary object
If mechanical contact is used for position sensing, then the structure is simple, but the durability decreases in harsh environments
Solution Approach 1:
The patent replaces mechanical contact-based sensing with a non-contact magnetic field sensing system. Magnets are attached to the valve shaft, and magnetic sensors are positioned in the housing to detect magnetic field changes during valve rotation. This eliminates mechanical wear and makes the system immune to harsh environmental conditions such as dust, moisture, and vibration, significantly improving durability while maintaining simple structure.
3Reliability
If magnetic sensors are used without mechanical contact, then reliability improves, but the device complexity increases
Solution Approach 1:
The patent replaces the mechanical switch with magnetic sensors and magnets. The magnets are mounted on the valve shaft, and magnetic sensors are positioned in the housing to detect magnetic field changes. While this introduces magnetic components, it eliminates complex mechanical contact mechanisms, switches, and associated wiring. The overall complexity is reduced while achieving non-contact sensing and improved reliability.
4Object-generated harmful factors
If non-contact magnetic sensing is used, then mechanical wear is eliminated, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses magnetic sensors positioned in the housing to detect magnetic field changes from magnets on the valve shaft. The non-contact nature eliminates mechanical wear entirely. While precise positioning of magnets and sensors is important for accurate valve position detection, the tolerance requirements are manageable through standard manufacturing practices and do not represent excessive precision demands.
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 high reliability and accuracy in detecting valve positions by eliminating mechanical contact, ensuring consistent performance even in harsh environments.
Implementation Method 1
a magnet is used to detect rotational positions without mechanical contact, utilizing magnetic flux to generate position signals
Implementation Method 2
utilizing magnetic flux to generate position signals
Implementation Method 3
the rotor and stator are made of magnetically permeable materials
Data Source
AI summary
A position sensor for sensing whether a rotatable element is in at least a first rotational position or a second rotational position is provided. A rotor is configured to be coupled to the rotatable element for rotation therewith, and is constructed at least partially of a magnetically permeable material and includes a first rotor pole. A stator is non-rotationally mounted, is constructed at least partially of a magnetically permeable material, is spaced apart from the rotor, and comprises a first main pole and a first stealer pole. The first main pole and the first stealer pole are spaced radially apart from each other. A magnet is non-rotationally disposed adjacent to the stator and is spaced apart from the rotor. A first magnetic sensor is non-rotationally mounted between the stator and the rotor, is disposed adjacent the first main pole, and is radially offset from the first stealer pole.