Segmented Stator End Turn Volume Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The structural volume required for end windings of preformed coils in electrical machines is not optimized, leading to challenges in assembly and transportation of large machines, as conventional designs prevent the use of inwardly directed end windings due to space constraints.

Innovation Solution

A segmented stator design with preformed coils having inwardly directed end windings allows for assembly around a rotor, enabling easier disassembly and transportation, achieved by bending end windings inwardly and using two identical coil types with different orientations, and incorporating a third uncranked coil for denser packing and reduced overhang.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If preformed coils with outwardly directed end windings are used in a conventional complete hollow cylinder stator, then the rotor can be pushed into the stator, but the structural volume required by the end windings is large and assembly/disassembly is difficult

Engineering Contradiction:
Improvestructural volume of end windingsVSAvoidassembly and disassembly of stator and rotor
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The stator is divided into multiple arc-shaped segments that can be assembled together to form a complete hollow cylinder. This segmentation allows the stator to be disassembled for easy transportation and enables the use of inwardly directed end windings that would otherwise prevent rotor insertion. The segments are connected through connection elements to maintain structural integrity while allowing disassembly.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If preformed coils with inwardly directed end windings are used, then the structural volume of end windings is reduced, but the rotor cannot be pushed into the stator in a conventional complete hollow cylinder design

Engineering Contradiction:
Improvestructural volume of end windingsVSAvoidassembly of stator and rotor
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The stator is segmented into arc-shaped elements that can be assembled around the rotor in a step-by-step process. This allows the preformed coils with inwardly directed end windings to be installed on the segments before final assembly, enabling the rotor to be pushed into the incomplete stator structure and then have the remaining segments closed around it.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The preformed coils are prepared in advance with their end windings directed inwardly, and the stator segments are pre-assembled with these coils installed before the final assembly with the rotor. This preliminary preparation enables the unique assembly sequence where the rotor is inserted first, followed by closing the stator segments around it.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple coil variants with different cranking orientations are used, then overlapping of preformed coils is enabled, but the number of coil variants increases manufacturing complexity

Engineering Contradiction:
Improveoverlapping arrangement of preformed coilsVSAvoidnumber of coil variants
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single type of preformed coil with inwardly directed end windings serves multiple functions: it can be installed on different stator segments, and the inwardly directed configuration enables both compact packing and compatibility with the segmented stator-rotor assembly approach. This universal coil design eliminates the need for multiple coil variants with different cranking orientations.

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

Data Source

PatentEP2454802B1End turn arrangement
Publication Date: 2013.05.01 SIEMENS AG
  • EP2454802B1 patent drawingFigure 1
  • EP2454802B1 patent drawingFigure 2
  • EP2454802B1 patent drawingFigure 3

AI summary

The invention relates to an end turn arrangement in a stator of a dynamoelectric machine. In order to reduce, in a simple fashion, the volume required for the end turns of the form-wound coils, the stator is formed of segments (1) that have a substantially circular arc-shaped cross-section and can be combined into a stator by adding one or more other segments (1) having the same design. Each segment (1) has recesses (6, 7), within which at least one first form-wound coil (3), which is bent outward in the radial direction of the stator in the region of the end turns, and at least one second form-wound coil (4), which is bent inward in the radial direction of the stator in the region of the end turns, are arranged in the form of a tiered winding.