Rotor Position Sensor Using Split Magnet Phase Detection
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Solution Overview
Problem
The existing rotor position detection devices in motors require two magnetic elements to accurately determine the rotational direction and precise rotation angle, increasing manufacturing costs.
Innovation Solution
A rotor position detection device that uses one magnetic element, where two chips are disposed to face split magnets, with specific spacing and alignment to generate phase-different sensing signals, allowing for rotational direction and angle detection without the need for additional magnetic elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two magnetic elements are used to detect rotational direction, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the functions of two separate magnetic elements into a single magnetic element by configuring two chips to read magnetic signals from the same magnet at different spatial positions and angles. This combination approach maintains the rotational direction detection capability while reducing component quantity and manufacturing cost.
Solution Approach 2:
The patent introduces spatial dimensionality by positioning two chips at different locations and orientations relative to the single magnetic element. The first chip is positioned at a first position with a first reading direction, while the second chip is positioned at a second position with a second reading direction. This dimensional arrangement allows the system to extract directional information from a single magnet, achieving the same functional effect as two separate magnets would provide.
2Measurement precision
If two magnetic elements are used to determine rotation angle, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple sensing functions into a single sensor module containing two chips that read from one magnetic element. This integration reduces the overall device complexity by eliminating the need for multiple separate magnetic elements and their associated mounting structures, while still achieving precise rotation angle measurement through the coordinated readings from both chips.
Solution Approach 2:
The single magnetic element serves multiple functions by providing magnetic field information that both chips can read from different orientations. This multi-functional approach allows one magnetic element to replace what would traditionally require two separate magnetic elements, thereby reducing device complexity while maintaining measurement precision.
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 reduces manufacturing costs by enabling rotational direction detection using a single magnetic element while maintaining precision, thus lowering production expenses.
Implementation Method 1
The sensor determines a present position of the rotor by detecting a magnetic force of the sensing magnet installed to be rotatable in conjunction with the rotor
Implementation Method 2
A distance between the first chip and the second chip may correspond to a hypotenuse in a trigonometric ratio, an inclination angle between the first line and the second line may correspond to an acute angle in the trigonometric ratio, and a distance between the first chip and the second chip in the circumferential direction of the sensing magnet may correspond to a height in the trigonometric ratio
Data Source
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AI summary
The present invention provides a rotor position detection device including a sensor having a first chip and a second chip which are aligned with a first line and detect a change in magnetic flux in a sensing magnet, wherein the sensor has the first line which is inclined with respect to a second line passing through any one of the first chip and the second chip in a radial direction of the sensing magnet. Accordingly, the present invention provides an advantageous effect of detecting a rotational direction and a precise rotational angle of the motor by utilizing one sensor.