Inclined Magnet Angle Detection for Wide Servo Range
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Solution Overview
Problem
Conventional angle detecting devices for servo apparatuses, such as those using potentiometers, face issues with wear and limited detection range, while magnetic sensors like Hall elements have a narrower detectable range, which is insufficient for applications requiring ±60° to ±75° detection.
Innovation Solution
An angle detecting device with a rotatably supported magnet inclined relative to the shaft and a magnetic sensor, such as a Hall element, is arranged to increase the detection range without special processing, using an amplifying circuit to enhance the output based on magnetic flux changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Hall element is used as a magnetic sensor, then component wear is eliminated, but the detectable rotation angle range becomes narrower
Solution Approach 1:
The magnet is inclined at a specific angle (10-30 degrees) relative to the axial direction, transforming the detection from a single-dimensional axial arrangement to a two-dimensional oblique arrangement. This dimensional change allows the magnetic sensor to detect a wider rotation angle range (±65 degrees or more) while maintaining non-contact operation and reliability
2Adaptability or versatility
If a potentiometer is used as a detecting element, then the detectable rotation angle range is sufficient, but component wear occurs reducing reliability
Solution Approach 1:
The patent replaces the mechanical contact-based potentiometer system with a non-contact magnetic sensing system using a Hall element. This substitution eliminates mechanical wear between the brush and resistor while achieving enhanced detection range through the inclined magnet arrangement, thereby improving reliability without sacrificing adaptability
3Device complexity
If the magnet is arranged parallel to the magnetic sensor, then the structure is simple, but the detection range is limited to ±45°
Solution Approach 1:
The magnet is arranged obliquely at a specific angle (10-30 degrees) relative to the axial direction instead of parallel to the magnetic sensor. This angular arrangement in a different dimensional orientation expands the detection range to ±65 degrees or more while maintaining relatively simple structure and avoiding complex processing
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 extends the detectable range of the angle detecting device to ±65° or more, maintaining reliability and lifespan, comparable to potentiometer performance, while minimizing wear and improving linearity of the output voltage.
Implementation Method 1
an output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet
Implementation Method 2
The servo apparatus disclosed in Japanese Patent Application Publication No. 2011-030376 uses a Hall element as a magnetic sensor
Data Source
AI summary
An angle detecting device includes a rotatably supported magnet, and a magnetic sensor disposed opposite to the magnet. An output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet. The magnet is disposed such that a distance between the magnetic sensor and the magnet is changed by the rotation of the magnet.