Stator Radial Passage Cooling With Thermal Guides for Coil Heat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cooling systems for electrical machines, particularly in stators, are inefficient in evacuating heat from the coils located in the stator slots, leading to hot spots, reduced efficiency, and shortened lifespan due to inadequate heat dissipation.
Innovation Solution
The implementation of a thermal guide system with a radially oriented plate and extensions that contact the coils and casing/flanges, facilitating direct heat conduction to the outer casing, bypassing the stator body's poor thermal conductivity, and allowing for passive air or fluid cooling without complex pumping systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermal guides are inserted into stator slots to cool coils, then coil cooling is improved, but the complexity of the system increases
Solution Approach 1:
The thermal guides are integrated with the existing cooling jacket system rather than creating a separate cooling circuit. The guides conduct heat to the jacket, which already contains the cooling fluid circulation system, thereby combining the coil cooling function with the existing stator cooling infrastructure.
Solution Approach 2:
The thermal guides utilize the temperature differential and natural heat conduction properties to transfer heat from the coils to the cooling jacket. The system leverages the existing cooling fluid circulation in the jacket to remove heat, requiring minimal additional active components or control systems.
2Reliability
If electrical and thermal insulators are placed in stator notches to protect copper insulation, then insulation damage is prevented, but thermal resistance between copper and iron increases
Solution Approach 1:
The thermal guides serve as intermediary thermal conduction paths that bypass the insulating materials. By inserting the guides directly into the stator slots and contacting the coils, they create a dedicated thermal pathway that does not rely on heat conduction through the insulating layers, thus maintaining both insulation protection and thermal efficiency.
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 solution effectively reduces the temperature in radial passages by at least 30°C, enhances torque density, and extends the machine's lifespan by improving heat evacuation directly from the coils to the outer casing, simplifying assembly and reducing thermal resistance.
Implementation Method 1
the heat flow passes by conduction / convection from close to the copper, to the stator iron then to the jacket
Implementation Method 2
the heat flow passes by conduction / convection from close to the copper, to the stator iron then to the jacket before ending by convection in the heat transfer liquid
Data Source
Figure 1
Figure 1bis~2
Figure 3~4
AI summary
The invention relates to an electrical machine comprising a stator, a housing (4), and two flanges (5), the two flanges (5) being arranged respectively at the longitudinal ends of the housing, said stator (3) comprising a stator body (8) and coils (6), the stator body (8) comprising a multitude of radial passages arranged circumferentially and extending along the entire length of the stator body (8) for the passage of the coils (6) in the radial passages. Furthermore, the electrical machine comprises at least one thermal guide in at least one radial passage, the thermal guide comprising a plate (21) extending along the entire longitudinal length of the stator body (8) and oriented substantially radially, and two extensions (22) fixed longitudinally on either side of the plate, at the level of the outer radial periphery of the plate (21), the extensions (22) being in contact with the housing and/or the flanges.