Segmented Rotor Magnet Fixing to Prevent Short-Circuiting
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Solution Overview
Problem
Existing rotor designs face challenges in preventing magnet segments from short-circuiting and in minimizing the material usage for insulating members, which can lead to increased eddy currents and material costs.
Innovation Solution
The rotor design incorporates a rotor core with stacked iron core pieces forming magnet housing holes, where magnet members are separated and fixed using foaming fixing members that fill recesses formed by notches in the iron core pieces, eliminating the need for additional insulating members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating sheets are wound around multiple magnet segments to prevent short-circuiting, then the reliability of preventing magnet segments from short-circuiting is improved, but the quantity of substance (material usage for insulating members) increases
Solution Approach 1:
The insulating sheet is divided into multiple independent insulating portions, each corresponding to one magnet member. This segmentation allows each insulating portion to be independently positioned and fixed, eliminating the need for continuous winding around multiple magnets and reducing overall material usage while maintaining insulation effectiveness.
Solution Approach 2:
A resin layer is introduced as an intermediary substance between the insulating sheet and the magnet members. The resin layer enables reliable fixation of the insulating portions to the magnet members through bonding, ensuring that the insulating portions remain in place without requiring excessive material or complex winding structures.
2Ease of manufacture
If magnet segments are accommodated in magnet insertion slots, then the rotor structure is formed, but the magnet segments may come into contact and short-circuit, increasing eddy currents
Solution Approach 1:
Insulating portions are provided only at specific locations where magnet members require insulation, rather than covering entire magnet segments. The insulating portions are positioned between adjacent magnet members at their widest portions, providing localized insulation exactly where needed to prevent short-circuiting while minimizing material usage.
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 prevents magnet segments from short-circuiting and reduces the material usage for insulating members, thereby minimizing eddy currents and material costs while ensuring reliable magnet positioning and fixation.
Implementation Method 1
the insulating sheet described in the publication is wound in a B-shaped configuration around the pair of magnet segments, with both ends positioned on the dividing surfaces of the magnet segments. This arrangement prevents the magnet segments from short-circuiting.
Implementation Method 2
Each bonding layer has a foaming property that allows it to expand when heated. By foaming within a magnet insertion slot, the bonding layers fix the corresponding pair of magnet segments to the rotor core.
Implementation Method 3
The fixing members respectively fill spaces between an inner surface of the magnet housing hole and outer surfaces of the magnet members. The fixing members press the magnet members against the inner surface of the magnet housing hole by foaming of a foaming agent, thereby fixing the magnet members.
Data Source
AI summary
A rotor includes a rotor core that includes a magnet housing hole, multiple magnet members that are accommodated in the magnet housing hole in a state of being separated from each other in a planar direction orthogonal to the stacking direction, and multiple fixing members that respectively fill spaces between an inner surface of the magnet housing hole and outer surfaces of the multiple magnet members. The fixing members press the magnet members against the inner surface of the magnet housing hole by foaming of a foaming agent, thereby fixing the magnet members. The magnet housing hole includes multiple recesses that are respectively filled with the fixing members.