Electric Machine Stator Winding Overhang Sealing for Heat Dissipation
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Solution Overview
Problem
The existing winding head casting process for electrical machines is complex, costly, and inefficient in heat dissipation, leading to hotspots and reduced performance due to poor thermal connection between the winding head and the aluminum housing.
Innovation Solution
A method involving the application of a polymer layer to span the gaps between the winding ends and the laminated core, preventing the flow of liquid medium and allowing for a simplified winding head casting process without additional tools, using a thermoplastic hot melt adhesive applied in a network structure to ensure effective thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the winding head is left with air gaps for standard manufacturing, then the manufacturing process is simple, but heat dissipation is poor causing hotspots
Solution Approach 1:
The polymer layer is applied to the stator before the winding head casting process, preliminarily sealing the gaps between winding ends. This preliminary action prevents liquid casting compound from penetrating into the stator interior and creates a controlled pathway for heat dissipation, eliminating the need for complex internal mandrels and multiple processing steps.
Solution Approach 2:
The polymer layer acts as an intermediary substance between the winding ends and the liquid casting compound. It selectively allows the liquid medium to flow through designated paths while blocking unwanted penetration, thereby controlling the casting process and enabling simplified manufacturing without compromising heat dissipation.
2Temperature
If impellers are installed for heat dissipation, then cooling is improved, but the motor performance and efficiency are negatively impacted
Solution Approach 1:
The invention extracts and eliminates the impeller component from the motor design. Instead of using mechanical impellers to drive air convection, the polymer layer creates passive thermal pathways that allow heat dissipation without rotating parts, thereby maintaining motor performance and efficiency while achieving effective cooling.
Solution Approach 2:
The polymer layer enables the winding head to self-regulate heat dissipation through its inherent structure. The material's properties allow it to conduct heat away from hotspots and distribute thermal energy passively, eliminating the need for active cooling mechanisms like impellers that would interfere with motor performance.
3Temperature
If winding head encapsulation with thermally conductive molding material is used, then heat dissipation is improved, but material and process costs increase significantly
Solution Approach 1:
The polymer layer serves as a cost-effective, disposable sealing layer that is applied once before casting. It performs its function of preventing liquid compound penetration and facilitating heat dissipation without requiring expensive thermally conductive molding materials or complex encapsulation processes, thereby significantly reducing material and process costs.
Solution Approach 2:
The invention changes the approach to thermal management by using a polymer layer with specific thermal properties rather than expensive thermally conductive molding compounds. This parameter change in material selection and application method achieves effective heat dissipation while dramatically reducing both material costs and process complexity.
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 approach simplifies the winding head casting process, enhances heat dissipation by thermally connecting the winding head to the housing, reduces material and energy costs, and improves the performance class of the motor by minimizing hotspots and extending the service life.
Implementation Method 1
at least one of the intermediate spaces is spanned with a polymer layer in such a way that a flow of liquid medium through the at least one spanned intermediate space is prevented
Implementation Method 2
A method involving the application of a polymer layer to span the gaps between the winding ends and the laminated core, preventing the flow of liquid medium and allowing for a simplified winding head casting process without additional tools, using a thermoplastic hot melt adhesive applied in a network structure to ensure effective thermal conductivity
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a stator of an electric machine, the stator (1) comprising: - a laminated core (2) having grooves (21); and - a winding overhang (4); wherein: windings (22) are inserted into the grooves (21); the winding overhang (4) is formed from winding ends (23) protruding from the grooves (21) and has a distance (5) from a laminated core end (24); in a region between the laminated core end (24) and the winding overhang (4), the winding ends (23) run in such a way that, in said region, intermediate spaces (6) are formed between the winding ends (23); at least one of the intermediate spaces (6) is spanned by a polymer layer (7) such that the flow of liquid medium through the at least one covered intermediate space (6) is prevented.