Rotating Electrical Machine Coil Insulation Thermal Conductivity
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Solution Overview
Problem
Conventional rotating electrical machine coils face challenges in improving the thermal conductivity of the insulation layer at the coil end portion, leading to suboptimal cooling performance, especially since the coil end portion is not in contact with metal and experiences poor adhesion between insulation materials, limiting the effectiveness of high thermal conductivity materials.
Innovation Solution
A rotating electrical machine coil design featuring a main insulation layer formed by winding highly thermally conductive mica tape, a first outer-layer insulation layer made of heat-shrinkable material, and a second outer-layer insulation layer composed of highly thermally conductive resin material, such as liquid crystal polymer or polyphenylene sulfide, to enhance thermal conductivity and adhesion at the coil end portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional insulation materials are used at the coil end portion, then adhesion between insulation layers is poor causing gaps, but using high thermal conductivity materials does not improve cooling performance due to poor adhesion and lack of metal contact
Solution Approach 1:
The patent applies composite materials by combining multiple insulation layers with different properties: a base insulation layer, a heat-shrinkable intermediate layer, and a high-thermal-conductivity outer layer. This composite structure ensures both strong adhesion through the heat-shrinkable layer and improved cooling through the high-thermal-conductivity material, resolving the contradiction between adhesion reliability and cooling performance.
Solution Approach 2:
The patent changes the physical and chemical parameters of the insulation materials, specifically selecting materials with high thermal conductivity (such as those containing metal particles or having inherently high thermal conductivity) for the outer layer. This parameter change enables effective heat dissipation from the coil end portion while maintaining structural integrity through proper material selection.
2Temperature
If refrigerant flow is controlled to cool the coil end portion, then cooling performance is limited by poor adhesion and gap formation, but increasing refrigerant flow does not sufficiently improve cooling
Solution Approach 1:
The patent applies local quality by providing different insulation layer configurations at different locations: the coil side portion uses conventional insulation, while the coil end portion uses a specialized multi-layer structure with high thermal conductivity materials. This localized improvement enables efficient heat transfer from the coil end portion without affecting other parts, significantly improving overall cooling efficiency.
3Temperature
If high thermal conductivity insulation material is used at the coil end portion, then thermal conductivity should improve, but poor adhesion prevents effective heat transfer
Solution Approach 1:
The patent introduces a heat-shrinkable intermediate layer between the base insulation layer and the high-thermal-conductivity outer layer. This intermediary layer provides strong adhesion and ensures intimate contact between layers, eliminating gaps that would hinder heat transfer. The heat-shrinkable property allows this layer to conform and bond surfaces together, enabling the high-thermal-conductivity material to function effectively.
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 design significantly improves the thermal conductivity of the coil end portion, enhancing the cooling performance not only of the coil end but also the entire rotating electrical machine, including the inside of the iron core, by effectively transferring heat and maintaining adhesion under thermal expansion.
Implementation Method 1
the main insulation layer is formed by winding a highly thermally conductive mica tape
Implementation Method 2
a first outer-layer insulation layer made of a heat-shrinkable material is formed on an outer circumferential surface of the main insulation layer
Implementation Method 3
a second outer-layer insulation layer made of a highly thermally conductive resin material is formed on an outer circumferential surface of the first outer-layer insulation layer
Data Source
AI summary
According to the present invention, a wire insulation layer (112) and an interlayer insulation layer (113) are formed on a wire (111). A main insulation layer (114) is formed by winding highly thermally conductive mica tape. A first outer insulation layer (115) formed from heat-shrinking material and a second outer insulation layer (116) formed from a highly thermally conductive resin are formed at a coil end section. Due to this configuration, the thermal conductivity of the coil, particularly of the coil end section, is improved, thereby enabling improved cooling performance.