Annular Oil Distribution Assembly for Stator End-Winding Cooling
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Solution Overview
Problem
Existing electric drive units and power transmission devices face inefficiencies due to inadequate heat dissipation and lubrication, leading to reduced system efficiency, increased weight, and higher costs, particularly in vehicles where additional batteries may be needed to compensate for decreased range.
Innovation Solution
The implementation of a housing with a stator, stator cooling rings, and jet rings that encircle stator end-windings, featuring channels and holes to direct cooling oil effectively onto the end-windings, enhanced by seals to prevent leakage and customizable hole configurations for optimal oil flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling systems are used for stators, then basic cooling is provided, but cooling efficiency and heat dissipation performance are insufficient
Solution Approach 1:
The cooling system is segmented into multiple functional components: a stator cooling ring divided into cooling zones, multiple jet rings with spray holes positioned at different locations, and radial cooling channels. This segmentation allows targeted cooling of different stator regions including end-windings, improving overall cooling efficiency and heat dissipation performance.
Solution Approach 2:
Different regions of the stator receive customized cooling through locally positioned jet rings with spray holes directed at specific areas such as end-windings. The cooling system provides localized high-intensity cooling where heat generation is highest, rather than uniform cooling across the entire stator.
2Reliability
If additional batteries are added to compensate for decreased range, then vehicle range is maintained, but system weight and cost increase
Solution Approach 1:
The cooling system efficiently manages heat dissipation through optimized oil flow paths and spray mechanisms, maintaining motor performance and efficiency. This prevents energy loss and maintains vehicle range without requiring additional batteries, thereby avoiding increased system weight.
3Device complexity
If simple cooling channels are used, then device complexity is reduced, but cooling oil distribution uniformity is insufficient
Solution Approach 1:
The cooling system transitions from simple linear channels to a three-dimensional network of radial cooling channels extending from the stator cooling ring to multiple jet rings. This dimensional expansion enables cooling oil to reach multiple stator surfaces simultaneously, achieving uniform distribution without excessive complexity.
Solution Approach 2:
The stator cooling ring acts as an intermediary component that receives cooling oil and distributes it through radial channels to multiple jet rings. This intermediary structure simplifies the overall system by centralizing oil distribution while ensuring uniform delivery to various cooling zones.
4Temperature
If cooling oil flow is increased to improve cooling, then cooling efficiency improves, but oil leakage increases
Solution Approach 1:
Flexible sealing elements are employed at critical interfaces within the cooling system to prevent oil leakage. These sealing components accommodate thermal expansion and pressure variations while maintaining effective seals, allowing increased cooling oil flow without proportionate increases in leakage.
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 improves cooling and lubrication efficiency, maintaining system performance and extending the life span of electric drive units by ensuring even distribution of cooling oil to stator end-windings, thereby reducing the need for additional components like batteries.
Implementation Method 1
The first plurality of stator cooling channels extends radially from the stator cooling ring to the first jet ring and the second plurality of stator cooling channels extends radially from the stator cooling ring to the second jet ring
Implementation Method 2
providing oil through the stator cooling ring and into the first plurality of stator cooling channels and into the second plurality of stator cooling channels
Data Source
AI summary
Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.