Rotor Magnet Insertion Hole Arrangement to Raise Torque
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Solution Overview
Problem
The existing rotating electric machines with permanent magnets arranged in a V-shape configuration experience reduced torque due to the formation of single magnetic poles.
Innovation Solution
A rotating electric machine design featuring a rotor core with multiple magnet insertion holes arranged side by side and a magnetic slit extending inwardly from the outer surface, forming one magnetic pole, which increases torque by optimizing magnetic flux paths and reducing magnetic saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If permanent magnets are arranged in a V-shape configuration with pairs of magnets, then the magnetic pole structure is simplified, but the torque of the rotating electric machine is reduced
Solution Approach 1:
The rotor core is divided into multiple segments along the radial direction, with each segment containing magnet insertion holes. Multiple permanent magnets are arranged in the radial direction within a single magnetic pole, creating a segmented magnet configuration that increases torque while maintaining the magnetic pole structure
Solution Approach 2:
The patent transitions from a two-dimensional arrangement (pairs of magnets in a V-shape) to a three-dimensional arrangement by placing multiple permanent magnets in the radial direction within each magnetic pole. This dimensional change allows for increased torque production without complicating the magnetic pole structure
2Force
If multiple permanent magnets are arranged in the radial direction within one magnetic pole, then torque is increased, but magnetic saturation may occur in the rotor core
Solution Approach 1:
Magnetic slits are introduced as intermediary elements between the permanent magnets and the rotor core outer periphery. These slits act as magnetic flux barriers that prevent magnetic saturation in the rotor core while allowing the multiple permanent magnets to be arranged in the radial direction for increased torque
Solution Approach 2:
Magnetic slits are strategically positioned at specific locations where magnetic flux concentration occurs. This local modification of the rotor core structure prevents magnetic saturation in critical areas without affecting the overall torque-generating capability of the multiple permanent magnet arrangement
3Stress or pressure
If magnetic slits are formed in the rotor core to prevent magnetic saturation, then magnetic flux paths are optimized, but the rotor core structure becomes more complex
Solution Approach 1:
The rotor core is segmented into multiple regions by introducing magnetic slits at strategic locations. This segmentation creates distinct magnetic flux paths that prevent saturation while maintaining a relatively simple overall rotor core structure through systematic placement of the slits
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 configuration with three or more magnet insertion holes enhances torque production and suppresses magnetic saturation, leading to improved performance compared to conventional designs.
Implementation Method 1
The rotor includes: a rotor core having a magnet insertion hole group including a plurality of magnet insertion holes; and a permanent magnet group including a plurality of permanent magnets inserted in the plurality of magnet insertion holes of the magnet insertion hole group, respectively
Implementation Method 2
in a part of the rotor core between the radially-outer side surface of the rotor core and the magnet insertion hole group, a magnetic slit is formed to extend in a shape convex toward the center of the rotor from the radially-outer side surface of the rotor core
Data Source
AI summary
The rotating electric machine includes: a rotor; and a stator, wherein the rotor includes: a rotor core having a magnet insertion hole group including a plurality of magnet insertion holes; and a permanent magnet group including a plurality of permanent magnets inserted in the plurality of magnet insertion holes of the magnet insertion hole group, respectively, wherein the plurality of magnet insertion holes are arranged side by side in a shape convex toward a center of the rotor from a radially-outer side surface of the rotor core, wherein the permanent magnet group forms one magnetic pole, wherein, in a part of the rotor core between the radially-outer side surface and the magnet insertion hole group, a magnetic slit is formed to extend in a shape convex toward the center of the rotor from the radially-outer side surface, and wherein the magnet insertion hole group includes three magnet insertion holes.