Salient Pole Rotor In-Situ Winding with Undercut Pole Body

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Solution Overview

Problem

Existing salient pole rotors face challenges in coil manufacturing, including costly brazing processes that damage insulation and physical restrictions imposed by separate pole tips, limiting operating speed and torque capabilities.

Innovation Solution

The design incorporates an undercut on the pole body to facilitate in-situ winding of coils, allowing for the formation of 'strip-on-edge' coils without brazing, utilizing undercuts to shape and support the conductive material, and enabling axial movement for efficient coil placement and insulation integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If brazing is used to join coil segments on pole bodies, then coil assembly is achieved, but insulation is damaged by brazing heat and manufacturing costs increase

Engineering Contradiction:
Improvecoil assemblyVSAvoidinsulation damage
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful brazing process from the coil assembly method. Instead of brazing coil segments, the invention uses pre-formed coils that are mechanically secured to pole bodies using retaining rings and clamping structures, eliminating thermal damage to insulation while achieving secure coil assembly

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces intermediary components (retaining rings, clamping structures, and mounting brackets) that mediate between the coil and pole body. These intermediaries provide mechanical securing without thermal contact, allowing coil assembly while protecting insulation from brazing heat

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If separate pole tips are used to allow pre-formed coils to be mounted, then coil placement flexibility improves, but rotor design is restricted and operating speed is limited

Engineering Contradiction:
Improvecoil placement flexibilityVSAvoidoperating speed
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The patent merges the pole tip with the pole body to form an integral structure. This combination eliminates the separate pole tip design constraints, allowing pre-formed coils to be mounted directly on the pole body while enabling higher operating speeds and greater rotor diameter options that were previously restricted

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If separate pole tips with pole screws are used, then coil mounting is facilitated, but the force that can be applied is limited which restricts rotor diameter and torque

Engineering Contradiction:
Improvecoil mountingVSAvoidclamping force
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The patent employs curved retaining rings that conform to the cylindrical surface of the pole body. This curved geometry distributes clamping force more effectively around the coil, providing sufficient securing force for larger rotor diameters and higher torque applications while maintaining ease of coil mounting

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Ease of manufacture

If brazing process is used for coil assembly, then coil segments can be joined, but additional cleaning is required after brazing and manufacturing complexity increases

Engineering Contradiction:
Improvecoil segment joiningVSAvoidmanufacturing process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts the brazing operation entirely from the manufacturing process. Pre-formed coils are assembled using mechanical retention methods (retaining rings, clamps, and mounting brackets) that require no thermal processing or post-brazing cleaning, significantly simplifying the manufacturing process while achieving secure coil-to-pole connections

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3334011B1Salient pole rotors and methods for winding rotor coils thereon
Publication Date: 2020.03.25 GE ENERGY POWER CONVERSION TECHNOLOGY LTD(GB)
  • EP3334011B1 patent drawingFigure 1
  • EP3334011B1 patent drawingFigure 2
  • EP3334011B1 patent drawingFigure 3

AI summary

The present invention relates to salient pole rotor for an electrical machine, e.g., a motor or generator. The rotor comprises a plurality of salient poles (1), each pole having a pole body (2) and an integral pole tip (4). The rotor further comprises a rotor winding with a plurality of coils, each coil having a plurality of turns and being positioned on the pole body (2) of a respective salient pole (1). Each pole body (2) includes a coil winding part (2A) having an outer profile around which the turns of the respective coil are wound in-situ. Each turn includes two substantially straight axially-extending sides and an inner profile that differs from the outer profile of the coil winding part (2A).