Ferromagnetic Polymer Stator Core for Electric Machine Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Permanent magnet rotary electric machines face challenges with insufficient cooling, complex assembly, high weight due to iron cores, and heat generation limitations, which affect their performance and efficiency.
Innovation Solution
A stator coil arrangement with a ferromagnetic core composed of a polymer matrix and functional filler, featuring fluid channels for cooling and a high thermal conductivity, allowing for improved heat removal and reduced weight, while maintaining sufficient magnetic permeability and electrical insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a traditional iron core is used in the stator, then sufficient magnetic permeability is achieved, but the weight of the machine increases significantly
Solution Approach 1:
The patent uses a composite material consisting of ferromagnetic particles dispersed in a polymer matrix to create a ferromagnetic plastic core. This composite structure combines the magnetic properties of ferromagnetic materials with the lightweight characteristics of polymers, achieving sufficient magnetic permeability while significantly reducing the weight compared to traditional solid iron cores.
2Power
If the stator core operates at high load levels, then higher power output is achieved, but heat generation increases and cooling becomes insufficient
Solution Approach 1:
The patent modifies the thermal parameter of the stator core by selecting polymer matrices with specific thermal conductivity values (minimum 0.1 W/mK). This parameter change enables more efficient heat dissipation from the core, allowing the machine to operate at higher power levels without excessive temperature rise that would limit performance.
3Loss of energy
If ferromagnetic material is used to provide high magnetic permeability, then magnetic coupling is improved, but the material must withstand electrical insulation requirements
Solution Approach 1:
The composite structure of ferromagnetic particles in an electrically insulating polymer matrix inherently provides both magnetic permeability and electrical insulation. The polymer binder acts as an electrical insulator between conductive ferromagnetic particles, preventing eddy current formation while maintaining magnetic coupling, thus satisfying both magnetic and insulation requirements simultaneously.
4Temperature
If the polymer matrix has high thermal conductivity for better cooling, then heat removal is improved, but the electrical insulation properties may be compromised
Solution Approach 1:
The patent optimizes the polymer matrix by selecting materials and formulations that achieve a minimum thermal conductivity of 0.1 W/mK while maintaining adequate electrical insulation properties. This parameter optimization allows the core to dissipate heat effectively without compromising the electrical insulation necessary for reliable operation at high voltages.
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 solution enables enhanced cooling, increased load capacity, reduced weight, and improved performance of permanent magnet rotary electric machines, with efficient heat management and magnetic coupling, leading to higher efficiency and voltage induction.
Implementation Method 1
the functional filler comprising a ferromagnetic material. The ferromagnetic material provides a relatively high relative magnetic permeability
Implementation Method 2
Said ferromagnetic core comprises at least one fluid channel extending through said core. The fluid channel allows a fluid to pass through the fluid channel thereby allowing excess heat to be removed from the core
Implementation Method 3
The polymer matrix composition has a minimum thermal conductivity in a range of 0.1 W/mK
Implementation Method 4
at least one winding of a conductor wound around said ferromagnetic core
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A ferromagnetic core (16) of a stator sub-assembly (14) comprises a compound including a polymer matrix composition and a functional filler, including ferromagnetic material, magnetic material or a combination thereof. Additionally, said ferromagnetic core (16) comprises at least one cooling fluid channel (18) extending through the ferromagnetic core (16). Moreover, a stator of a permanent magnet electric rotary machine comprising a stator frame, having openings to receive a cooling fluid flow, and stator sub-assemblies (14). Said permanent magnet machine comprises a stator and a rotor connected to a rotational shaft, wherein the rotor is provided with permanent magnets. The permanent magnets face the ferromagnetic cores (16) of stator sub-assemblies (14). The rotor comprises ventilation means for generating a cooling fluid flow through said cooling fluid channels (18) of said ferromagnetic cores (16), when the machine is in operation.