Electric Valve Rotor Position Sensing With Fixed Magnet Gap
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Solution Overview
Problem
Existing electrically operated valves face challenges in accurately detecting the angle of rotation of a rotating body using magnetic sensors arranged radially outward, leading to increased costs, complex support mechanisms, and loss of rotational information when power is turned off.
Innovation Solution
An electrically operated valve design featuring a rotor member, stator member, permanent magnet member, and angle sensor arranged in a configuration where the permanent magnet and angle sensor have a fixed distance, with a guide member to facilitate relative movement, and biasing members to maintain the magnet's position, allowing for precise detection of the rotor's angle of rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If magnetic sensors are arranged radially outward from the rotating body to detect angle of rotation, then the detection mechanism is simplified, but measurement precision deteriorates when multiple sensors are not used
Solution Approach 1:
A permanent magnet is introduced as an intermediary element that rotates with the rotor. The angle sensor detects the position of this permanent magnet to determine the rotor's angular position. This mediator enables precise angle detection without requiring multiple direct sensors on the rotor itself, thus maintaining simplicity while improving measurement precision.
2Measurement precision
If multiple magnetic sensors are arranged radially outward to improve detection precision, then measurement precision improves, but device complexity and cost increase
Solution Approach 1:
The permanent magnet attached to the rotor serves as a single intermediary that provides continuous angular position information. A single angle sensor detects the magnet's position, eliminating the need for multiple sensors and their complex support structures, thereby achieving precise measurement without increased device complexity.
Solution Approach 2:
The permanent magnet performs multiple functions: it generates the magnetic field for angle detection, rotates with the rotor to provide dynamic position information, and serves as a reference for the angle sensor. This multi-functional element replaces what would otherwise require multiple dedicated sensors.
3Device complexity
If magnetic sensors detect angle based on Hall current variations, then the detection mechanism is simple, but reliability deteriorates because information is lost when power is turned off
Solution Approach 1:
The permanent magnet continuously maintains its magnetic field configuration as the rotor rotates, providing persistent angular position information. The angle sensor detects this self-maintained magnetic field to determine absolute position, enabling the system to retain position information without continuous power supply to the sensor itself.
Solution Approach 2:
The permanent magnet is pre-configured on the rotor to generate a consistent magnetic field pattern. This preliminary setup ensures that whenever the system operates, the angular position information is already encoded in the magnetic field, allowing the sensor to read absolute position immediately without needing power-cycled calibration.
4Device complexity
If the distance between permanent magnet and angle sensor varies during rotation, then the mechanism is simpler, but measurement precision deteriorates
Solution Approach 1:
The angle sensor and permanent magnet are positioned and configured to maintain a constant radial distance throughout the rotation. This equipotential arrangement ensures that the magnetic field strength at the sensor remains consistent, eliminating distance variations that would otherwise cause measurement errors and requiring complex compensation mechanisms.
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
This configuration enables accurate detection of the valve body's position by continuously monitoring the angle of rotation, reducing costs and complexity while maintaining accurate readings even when power is cycled.
Implementation Method 1
a permanent magnet member which turns together with the rotor member, and an angle sensor which is arranged above the permanent magnet included in the permanent magnet member and detects an angle of rotation of the permanent magnet
Data Source
AI summary
The invention provides an electrically operated valve which can more accurately detect a position of a valve body. An electrically operated valve is provided with a valve shaft, a valve body, a rotor member which is movable together with the valve shaft in a parallel direction to a first direction, a stator member which applies a turning force to the rotor member, a permanent magnet member which turns together with the rotor member, an angle sensor which detects an angle of rotation of the permanent magnet, and a guide member which guides a relative movement of the rotor member or the valve shaft in relation to the permanent magnet member. A distance between the permanent magnet and the angle sensor is fixed when the permanent magnet member turns.