Stator Winding Fixation Using Absorbent Nonwoven Material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stator designs for electric machines face challenges in extending service life and producibility, particularly in effectively fixing conductor bars within the stator lamination stack and providing efficient cooling for the stator winding.
Innovation Solution
A stator design utilizing a nonwoven material that can be saturated with a cooling liquid to act as both a fixing device and insulation, allowing the nonwoven material to expand and securely hold conductor bars in place without the need for additional fixing elements, while also enabling direct cooling through pressure differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional fixing devices and impregnation methods are used, then conductor bars are secured in slots, but device complexity and manufacturing steps increase
Solution Approach 1:
The patent combines multiple functions into a single nonwoven material component: electrical insulation, fixation through expansion, and cooling liquid distribution. This eliminates the need for separate fixing elements and impregnation processes, directly resolving the contradiction between reliable fixation and device complexity
Solution Approach 2:
The nonwoven material serves multiple purposes simultaneously: it provides electrical insulation between conductor bars and the stator lamination stack, acts as a fixing device through volume expansion, and functions as a cooling medium distributor. This multi-functionality reduces the overall number of components while maintaining reliable fixation
2Reliability
If additional fixing elements are used, then conductor bars are securely fixed, but manufacturing time and complexity increase
Solution Approach 1:
The nonwoven material is pre-positioned in the slot around the conductor bars before final assembly. Its fixation function is activated automatically when cooling liquid is introduced, causing the material to expand and secure the conductor bars. This eliminates the need for separate fixing operations and improves manufacturing efficiency
Solution Approach 2:
The nonwoven material performs self-fixation through its expansion response to cooling liquid absorption. The material automatically adjusts its volume to secure the conductor bars without requiring additional fixing elements or manual adjustment, thereby simplifying the manufacturing process
3Device complexity
If nonwoven material expands with cooling liquid, then conductor bars are fixed without additional elements, but cooling system complexity increases
Solution Approach 1:
The nonwoven material's porous structure allows it to absorb and retain cooling liquid, enabling volume expansion for fixation purposes. The same porosity facilitates controlled distribution of cooling liquid to the conductor bars, managing pressure effects while maintaining the dual function of fixation and cooling
4Productivity
If impregnation is omitted, then manufacturing steps are reduced, but insulation reliability may be compromised
Solution Approach 1:
The patent extracts the insulation function from the traditional impregnation process and integrates it into the nonwoven material itself. The material is designed to provide adequate electrical insulation without requiring additional impregnation steps, thus maintaining insulation reliability while simplifying manufacturing
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 the service life and producibility of the stator by providing stable fixation and direct cooling of the conductor bars, eliminating the need for additional fixing elements and impregnation, thus improving the overall performance and efficiency of the stator.
Implementation Method 1
The nonwoven material that can be saturated with a cooling liquid is arranged in the slot. The nonwoven material may comprise a volume that increases with absorption of the cooling liquid such that the conductor bars are fixed in the slot by the nonwoven material saturated with the cooling liquid.
Implementation Method 2
A pressure difference acts on the nonwoven material saturated with the cooling liquid. The pressure difference has the effect that the conductor bars fixed by the saturated nonwoven material are surrounded by cooling liquid. Direct cooling of the windings is thus made possible in a simple manner.
Data Source
AI summary
A stator (10) of an electric machine has a stator lamination stack (16) that includes stator laminations. The stator (10) also has at least one stator winding (15) defined by conductor bars (11-14) arranged in slots (17) of the stator lamination stack (16) and fixed in the slots (17) of the stator lamination stack (16) with the aid of a fixing device (22). The fixing device (22) in a slot (17), a nonwoven material (20) which can be saturated with a cooling liquid (28).