Electric Machine Rotor Segments with Dual Magnetic Modules
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Solution Overview
Problem
Existing electric machines experience irreversible demagnetization due to oscillation of the work point along the normal magnetization curve, leading to efficiency loss, as the load line varies during operation, causing modules to exceed their maximum energy product at nominal operating temperatures.
Innovation Solution
The electric machine design incorporates rotor segments with first and second modules of different magnetic characteristics, where the first module, with higher thermal class and intrinsic coercive force, is positioned closer to the air gap, and the second module is further away, ensuring stability and efficiency by managing the magnetic field effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If modules with magnetic properties are used in the rotor, then the electric machine generates magnetic field for operation, but the work point oscillates along the normal magnetization curve causing irreversible demagnetization and efficiency loss
Solution Approach 1:
The patent applies local quality by using two different types of magnetic modules with distinct properties: first modules with higher thermal class positioned near the air gap, and second modules with lower thermal class positioned away from the air gap. This localized differentiation optimizes the magnetic circuit to prevent work point oscillation and irreversible demagnetization while maintaining efficient magnetic field generation.
2Device complexity
If the work point is designed to correspond to maximum energy product, then magnet size is minimized, but the load line variation during operation causes work point oscillation exceeding the threshold
Solution Approach 1:
The patent changes the magnetic parameters of different modules to resolve the contradiction. First modules have higher thermal class and are positioned near the air gap where magnetic field strength is highest, while second modules have lower thermal class and are positioned away from the air gap. This parameter differentiation stabilizes the work point along the load line, preventing oscillation-induced demagnetization while maintaining compact magnet dimensions.
3Power
If modules are positioned closer to the air gap, then magnetic field strength increases, but thermal class requirements increase leading to higher costs
Solution Approach 1:
The patent implements local quality by strategically positioning first modules with higher thermal class near the air gap where strong magnetic field is required, and second modules with lower thermal class away from the air gap where weaker field is acceptable. This localized material selection optimizes magnetic performance at critical locations while reducing overall manufacturing costs by using lower-cost materials where high performance is not critical.
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 maintains long-term efficiency and reduces costs by preventing demagnetization, allowing for greater oscillation of the work point within the operating temperature range, thus enhancing the overall performance and reliability of the electric machine.
Implementation Method 1
Each rotor segment comprising a gripper; magnetic guides; at least a first module (15) and a second module (16) of material with magnetic properties and permanently magnetizable
Implementation Method 2
The first module (15) and second module (16) having different magnetic characteristics; wherein the first module (15) is of a higher thermal class than the second module (16)
Data Source
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AI summary
An electric machine having a stator (2), and a rotor (3) which rotates with respect to the stator (2) about an axis of rotation (A); the rotor (3) having rotor segments (7) arranged about the axis of rotation (A); each rotor segment (7) having at least a first module (15) and a second module (16) of material with magnetic properties, and arranged radially, more specifically aligned radially with each other, with respect to the axis of rotation (A); and the electric machine being characterized in that the first module and second module (15, 16) have different magnetic characteristics.