Radial Spreading of Stator Winding Bars for Phase Separation

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Solution Overview

Problem

In large rotating electrical machines, achieving high dielectric strength in stator winding phase separation requires significant additional effort due to the need for different step angles and production of winding bars, which complicates the manufacturing process.

Innovation Solution

Implementing a radial spreading of winding bar ends instead of tangential spreading, allowing for a consistent twisting angle and increased radial distance between phases, simplifying production and enhancing dielectric strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tangential spreading of bar ends is implemented to increase dielectric strength between phases, then dielectric strength is improved, but device complexity and manufacturing effort increase due to requiring different step angles for different winding bars

Engineering Contradiction:
Improvedielectric strengthVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the spreading direction from tangential to radial, which fundamentally alters the geometric parameter of bar end arrangement. This parameter change allows all winding bars to maintain the same step angle while still achieving phase separation, thereby improving dielectric strength without increasing manufacturing complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of spreading bar ends tangentially (conventional approach), the patent inverts the approach by spreading them radially. This inversion resolves the contradiction by achieving the same dielectric strength improvement without requiring different step angles for different bars, thus maintaining uniform manufacturing parameters

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If tangential spreading of bar ends is implemented to increase dielectric strength, then dielectric strength is improved, but manufacturing time and productivity decrease due to additional production efforts

Engineering Contradiction:
Improvedielectric strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

By changing the spreading direction parameter from tangential to radial, the patent eliminates the need for variable step angles across different winding bars. This standardization of manufacturing parameters directly improves productivity by reducing the variety of production operations required

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The radial spreading approach creates a universal solution where all winding bars, regardless of their position or phase, can be manufactured with the same step angle and then spread radially during assembly. This universality simplifies the manufacturing process and increases productivity compared to the phase-specific tangential spreading approach

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP1811632B1Rotating electrical machine
Publication Date: 2018.03.14 GENERAL ELECTRIC TECH GMBH
  • EP1811632B1 patent drawingFigure 1
  • EP1811632B1 patent drawingFigure 2~3
  • EP1811632B1 patent drawingFigure 4a~5b

AI summary

The machine has a rotor (11) rotating around an axis and concentrically surrounded by a stator (12) with a stator winding that is inserted into a stator body. The stator winding in a concentric arrangement encloses a lower layer (16) and an upper layer (17) of axially extending winding bars. A radial spread angle (18) of bar ends of the winding bars is provided for increasing a radial interval between different phases, in the winding bars. A phase separation cover encloses a connection region between a phase connection and bar ends, and is made of a silicone material or polyester. An independent claim is also included for a method for manufacturing a rotating electrical machine.