Rotary Electric Machine Rotor Design for Position Detection Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary electric machines with embedded permanent magnets suffer from reduced position detection accuracy due to leakage flux interference, as the position detection magnet is affected by the magnetic flux of the permanent magnet.
Innovation Solution
A rotary electric machine design where the position detection magnet is disposed on an end surface of the rotor core orthogonal to the rotation axis, positioned differently from the embedded permanent magnets, with second through holes between adjacent permanent magnets to reduce leakage flux influence, and a stator wound around a stator core to minimize magnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the position detection magnet is disposed to overlap with the permanent magnet in the radial direction, then the structure is simplified, but the detection accuracy is reduced due to leakage flux interference
Solution Approach 1:
The patent resolves the contradiction by changing the spatial arrangement from radial overlap to axial separation. The position detection magnet is disposed on the end surface of the rotor core in the axial direction, while the permanent magnet is embedded in the rotor core in the radial direction. This dimensional separation eliminates leakage flux interference while maintaining structural simplicity.
2Measurement precision
If the position detection magnet is disposed at a position different from the permanent magnet in the radial direction, then the detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent implements radial separation by positioning the position detection magnet on the end surface of the rotor core in the axial direction, while the permanent magnet is embedded in the rotor core in the radial direction. This spatial separation in different dimensions eliminates leakage flux interference and improves detection accuracy without significantly increasing structural complexity.
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 enhances the accuracy of position detection by reducing the impact of leakage flux on the position detection magnet, improving the resolution and reliability of the sensor's readings, thereby maintaining high efficiency and reducing energy consumption and potential malfunctions.
Implementation Method 1
a rotary electric machine includes a rotor core (5) that rotates about a rotation axis (Zr), a plurality of permanent magnets (7) embedded in the rotor core (5) in a radial direction (DR) of the rotor core (5)
Implementation Method 2
a position detection magnet (8) that includes a plurality of magnetic poles disposed in the circumferential direction (C) of the rotor core (5), and disposed on an end surface (5TB) of the rotor core (5) in an extending direction of the rotation axis (Zr)
Data Source
AI summary
A rotary electric machine includes a rotor core that rotates about a rotation axis, a plurality of first magnets disposed in a circumferential direction of the rotor core and embedded in the rotor core, a second magnet that includes a plurality of magnetic poles disposed in the circumferential direction of the rotor core and is disposed on an end surface of the rotor core in an extending direction of the axis, the second magnet being disposed at a position in a direction orthogonal to the axis, different from positions at which the plurality of first magnets are disposed, and a stator provided on an outer side of the rotor core in the direction orthogonal to the rotation axis.