Rotating Sensing Apparatus With Holes and Offset Magnet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic flux interference between main poles and frequency generator poles in motor sensing units leads to waveform distortion, and the limited size of the sensing magnet restricts the availability of space for a dummy track, making it difficult to secure sufficient space for interference reduction.
Innovation Solution
A sensing unit is designed with a sensing plate having multiple holes along its edge and a sensing magnet positioned closer to the rotating shaft, utilizing optical sensors and Hall integration chips to detect changes in the plate and magnet, respectively, which allows for accurate rotation measurement while inhibiting magnetic flux interference by potentially removing FG poles or using the holes as FG poles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If main poles and FG poles are arranged closely on the sensing magnet, then rotation angle measurement accuracy is improved, but magnetic flux interference occurs causing waveform distortion
Solution Approach 1:
The sensing plate is segmented into multiple functional zones: an inner race with main poles for rotation detection, an outer race with FG poles for frequency generation, and a dummy track positioned between them. This spatial segmentation separates the magnetic flux paths of main poles and FG poles, preventing magnetic flux interference while maintaining accurate rotation angle measurement.
2Object-generated harmful factors
If a dummy track is disposed between main poles and FG poles to reduce interference, then waveform distortion is reduced, but the size of the sensing magnet increases
Solution Approach 1:
The sensing plate serves multiple functions: it provides the main poles for rotation detection, the FG poles for frequency generation, and the dummy track for interference reduction, all within a single integrated component. This multi-functionality eliminates the need for separate interference reduction structures, maintaining compact sensing magnet size while reducing waveform distortion.
Solution Approach 2:
The dummy track is positioned in the radial dimension between the inner race (main poles) and outer race (FG poles) of the sensing plate. By utilizing the radial space that would otherwise be unused, the dummy track provides interference reduction without significantly increasing the overall sensing magnet size.
3Productivity
If the sensing magnet size is reduced to minimize motor size, then productivity is improved, but sufficient space for dummy track cannot be secured
Solution Approach 1:
The dummy track is positioned locally in the radial region between the main poles and FG poles, utilizing only the specific space needed for interference reduction. This localized approach minimizes the overall sensing magnet size while still providing sufficient space for the dummy track to function effectively.
4Measurement precision
If optical sensors and Hall integration chips are used for detection, then rotation detection accuracy is improved, but device complexity increases
Solution Approach 1:
The optical sensor and Hall integration chip are integrated into a single sensing unit with a unified structure. The sensing plate with its inner and outer races is designed to work with both detection methods simultaneously, allowing accurate rotation detection while maintaining relatively simple device architecture through functional integration.
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 effectively reduces waveform distortion and allows for accurate rotation angle measurement, potentially reducing costs by eliminating the need for a dummy track and minimizing the size of the sensing magnet, thereby enhancing motor performance and efficiency.
Implementation Method 1
a first sensor that is disposed over the sensing plate and detects a change in the sensing plate, wherein the first sensor may be an optical sensor
Implementation Method 2
a second sensor that is disposed over the sensing magnet and detects a change in the sensing magnet, wherein the second sensor may be a Hall integration chip (IC)
Implementation Method 3
magnetic flux interference between the main poles and the FG poles may occur
Implementation Method 4
a sensing magnet that is mounted on the sensing plate and is disposed closer to the rotating shaft than the plurality of holes
Data Source
AI summary
A motor includes a rotating shaft, a rotor that surrounds the rotating shaft, rotates along with the rotating shaft, and includes a drive magnet, and a sensing unit that surrounds the rotating shaft, is disposed over the rotor, and detects rotation of the rotor, wherein the sensing unit includes a sensing plate that includes a plurality of holes that are formed along with an edge of the sensing plate, a sensing magnet that is mounted on the sensing plate and is disposed closer to the rotating shaft than the plurality of holes, a first sensor that is disposed over the sensing plate and detects a change in the sensing plate, and a second sensor that is disposed over the sensing magnet and detects a change in the sensing magnet.