Permanent Magnet Rotor Core Structure for No-Load Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary electric machines face challenges in reducing losses during no-load operation while maintaining maximum output torque during high-load operation, with existing solutions complicating the configuration due to the need for oil passages and hydraulic pressure control.
Innovation Solution
A rotor design featuring a saturation portion with core protrusions and nonmagnetic portions within the magnet accommodating holes, which are magnetically saturated during no-load operation to reduce iron loss and prevent magnetic saturation during high-load operation, thereby minimizing losses and maintaining torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a saturation portion is formed in the rotor core to reduce loss during no-load operation, then loss reduction is achieved, but the configuration becomes complicated
Solution Approach 1:
The saturation portion is merged with the magnet accommodating hole structure, combining two functional elements into a single integrated component. The core protrusion that forms the saturation portion is simultaneously part of the magnet accommodating hole's structural framework, eliminating the need for separate saturation portion components and reducing overall configuration complexity.
Solution Approach 2:
Magnetic saturation is applied locally only in specific regions where core protrusions are formed between the magnet accommodating hole wall and the permanent magnet surfaces. This localized approach reduces loss during no-load operation without affecting the overall rotor structure or requiring global structural modifications, thereby maintaining simplicity while achieving energy efficiency.
2Loss of energy
If core protrusions are added to form saturation portions, then loss reduction is achieved, but manufacturing difficulty increases
Solution Approach 1:
The core protrusions forming the saturation portion are created during the initial rotor core manufacturing process, before the permanent magnets are installed. By pre-forming these protrusions in the rotor core structure, the subsequent magnet installation becomes simpler, and the overall manufacturing process is streamlined without requiring additional complex steps after core fabrication.
Solution Approach 2:
The saturation portion structure is combined with the magnet accommodating hole geometry, so that a single manufacturing process for the rotor core simultaneously creates both the accommodating hole and the saturation-inducing protrusions. This integration eliminates the need for separate manufacturing steps for each feature, reducing manufacturing complexity.
3Loss of energy
If saturation portions are formed near permanent magnets, then loss reduction is achieved, but magnetic saturation during high-load operation may occur
Solution Approach 1:
Magnetic saturation is localized to specific regions (core protrusions) positioned between the magnet accommodating hole wall and the permanent magnet surfaces. This localized saturation reduces no-load loss by preventing flux leakage in these specific areas, while the overall magnetic circuit remains capable of handling high-load conditions without experiencing unwanted magnetic saturation that would reduce output torque.
Solution Approach 2:
The saturation portion is designed to provide just enough magnetic saturation during no-load operation to reduce loss, without creating excessive saturation that would interfere with high-load performance. The core protrusions are dimensioned to achieve partial saturation under no-load conditions while maintaining adequate magnetic flux capacity during high-load operation.
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 rotor design effectively reduces losses during no-load operation while preserving maximum output torque during high-load operation, simplifying the configuration and manufacturing process by incorporating easily formed saturation portions within the magnet accommodating holes.
Implementation Method 1
a saturation portion which is magnetically saturated during no-load operation of the rotary electric machine is formed in the rotor core
Implementation Method 2
a magnetic field of the stator generated by a current passing through the coil and a magnetic field of the rotor generated by the magnet attached to the rotor interact with each other to rotationally drive the rotor
Data Source
AI summary
A saturation portion which is magnetically saturated during no-load operation of the rotary electric machine is formed in the rotor core at a position facing at least one of the first main surface and the second main surface of the permanent magnet when viewed in the axial direction. When viewed in the axial direction, the saturation portion includes at least one core protrusion firmed between the wall portion of the magnet accommodating hole and at least one of the first main surface and the second main surface of the permanent magnet such that a part of the rotor core extends in a direction intersecting the first main surface or the second main surface, and at least one nonmagnetic portion formed between the wall portion of the magnet accommodating hole and at least one of the first main surface and the second main surface of the permanent magnet.