Motor End Plate Cooling for High-Density End Windings
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Solution Overview
Problem
Existing electric motor cooling systems, such as liquid-cooled aluminum jackets, fail to effectively cool end windings, leading to hot spots and degradation due to inadequate heat dissipation and mechanical support, particularly for hairpin and other non-compressible conductive windings.
Innovation Solution
An electric motor design featuring end plates with indentations filled with thermally conductive, electrically insulating potting material to interface with end windings, providing mechanical support and efficient heat transfer via coolant channels, which are fluidically coupled to the motor's cooling jacket and rotor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If compression is applied to cool end windings against the housing, then heat dissipation is improved, but vibrations are transmitted and mechanical degradation occurs
Solution Approach 1:
A thermally conductive adhesive is introduced as an intermediary substance between the end windings and the end plate cooling channels. This adhesive layer provides optimal thermal contact for heat dissipation while acting as a vibration-dampening interface that protects the end windings from mechanical degradation, eliminating the need for direct compression.
Solution Approach 2:
The system changes the thermal contact parameter from mechanical compression to adhesive bonding. The thermally conductive adhesive maintains intimate thermal contact between the end windings and cooling channels while providing mechanical protection, thereby improving heat dissipation without transmitting damaging vibrations.
2Ease of operation
If air is present between the end winding and housing, then mechanical clearance is maintained, but cooling efficiency is reduced
Solution Approach 1:
The thermally conductive adhesive serves as an intermediary that eliminates air gaps between the end windings and end plate while accommodating assembly tolerances. This adhesive filler ensures continuous thermal contact for efficient heat transfer without requiring precision mechanical clearance control.
Solution Approach 2:
The adhesive creates a homogeneous thermal interface between the end windings and cooling channels, eliminating the heterogeneous air gaps that would otherwise impede heat transfer. This uniform thermal contact ensures consistent cooling efficiency across all end winding regions.
3Temperature
If direct oil cooling is used for end windings, then cooling effectiveness is improved, but system complexity and maintenance requirements increase
Solution Approach 1:
The cooling system merges the stator core cooling function and end winding cooling function into a single integrated liquid cooling circuit. The aluminum jacket and end plates with cooling channels form a unified thermal management system that eliminates the need for separate oil cooling systems, reducing complexity while maintaining cooling effectiveness.
Solution Approach 2:
The system replaces the mechanical oil cooling system with a liquid coolant circulation system using standardized cooling channels. This substitution eliminates the complexity of oil filtration, sealing, and maintenance while achieving comparable or superior cooling performance through the thermally conductive adhesive interface.
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 enhances power density and reduces losses by uniformly cooling the end windings, mitigating hot spots and extending the motor's lifespan while avoiding the complexities and inefficiencies of direct oil cooling systems.
Implementation Method 1
the indentations including a thermally conductive material to interface with the end windings
Implementation Method 2
at least one cooling channel to flow a coolant
Implementation Method 3
at least one cooling channel to flow a coolant
Data Source
AI summary
Methods and systems are provided for an electric motor. In one example, the electric motor may include a stator with end windings protruding axially, along a central axis of rotation of the electric motor, from a first end of the stator and a first end plate arranged at the first end of the stator. The first end plate may have an inner face with indentations configured to receive the end windings, the indentations including a thermally conductive material to interface with the end windings. In addition, the first end plate may include at least one cooling channel for flowing a coolant.