Slotless Resolver Cylindrical Stator Winding Design

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Solution Overview

Problem

Conventional resolvers require complex molding designs for teeth and slots, leading to high-frequency components in output waveforms and inadequate insulation due to uneven silicon coating, complicating fabrication and insulation.

Innovation Solution

A slotless resolver with a cylindrical stator core featuring distribution windings for sine and cosine output windings, alternately stacked and coated with insulating resin, eliminating the need for teeth and slots, and utilizing a specialized winding tool for manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If teeth and slots are used for coil windings in a conventional resolver, then the coils can be wound on specific locations, but the fabrication becomes complicated requiring complex molding design

Engineering Contradiction:
Improvefabrication simplicityVSAvoidmolding design complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent removes the teeth and slots structure from the stator core, extracting the problematic elements that caused complex molding design. The coils are now wound directly on the smooth cylindrical surface of the stator core without requiring tooth-shaped protrusions or slot structures, thereby simplifying the molding design while maintaining the winding functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If concentration winding structure is used on teeth only, then the winding process is simplified, but high-frequency components are caused in the output waveform due to broken voltage sections between teeth

Engineering Contradiction:
Improvewinding process simplicityVSAvoidoutput waveform quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies different winding structures to different regions of the stator core. Distribution windings are used in radial sections to ensure continuous voltage output and eliminate high-frequency components, while concentration windings can be used in axial sections for simplicity. This local differentiation of winding quality resolves the contradiction between winding simplicity and waveform quality.

Inventive Principle:
Principle #3Local quality

3Reliability

If a large amount of silicon is coated to insulate coils wound on teeth, then insulation coverage is attempted, but the silicon is not evenly coated on every corner resulting in insufficient insulation property

Engineering Contradiction:
Improveinsulation propertyVSAvoidcoating process difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By removing the teeth structure, the patent eliminates the geometric complexity that prevented even silicon coating. The smooth cylindrical surface of the stator core allows uniform coating of insulating resin without dead corners or hard-to-reach areas, thereby achieving sufficient insulation property with a simpler coating process.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If teeth and slots are fabricated in the stator, then coil winding locations are defined, but the overall design and fabrication complexity increases

Engineering Contradiction:
Improvecoil winding location definitionVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the stator core surface universally suitable for coil winding by removing specialized tooth and slot structures. The smooth cylindrical surface can accommodate various winding patterns (concentration or distribution windings) without requiring specific geometric features, thereby defining coil winding locations through winding pattern design rather than structural features.

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

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

Simplifies fabrication, removes high-frequency components, ensures sufficient insulation with reduced silicon coating, and achieves a more compact design by eliminating protrusions, resulting in a more efficient and reliable resolver.

Implementation Method 1

coated with insulating resin

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

a plurality of sine output windings attached on an excitation winding pattern in the circumferential direction in such a way as to be stacked and each forming a distribution winding; and a plurality of cosine output windings attached on the excitation winding pattern in the circumferential direction in such a way as to be stacked

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2813819B1Slotless resolver, method for manufacturing same, and wiring tool used therefor
Publication Date: 2017.08.09 DAESUNG ELECTRIC CO LTD
  • EP2813819B1 patent drawingFigure 1~2
  • EP2813819B1 patent drawingFigure 3~4
  • EP2813819B1 patent drawingFigure 5~6

AI summary

The present invention relates to a resolver having a stator for detecting the rotational position of a rotor rotating at the inner center thereof. The stator includes: a stator core having a cylindrical shape; a plurality of excitation windings attached to the inner surface of the stator core at a predetermined distance in the circumferential direction, each of the plurality of excitation windings being tightly wound; a plurality of sine output windings stacked and attached to the patterns of the excitation windings in the circumferential direction, each of the plurality of sine output windings being loosely wound; and a plurality of cosine output windings stacked and attached to the patterns of the excitation windings in the circumferential direction, the sine output windings and the cosine output windings being alternately attached such that the sine output windings and the cosine output windings have the same winding distribution. Therefore, it is possible to easily manufacture the resolver without designing a complicated mold necessitated by the removal of a tooth and slot structure in the stator. Also, it is possible to remove high-frequency components from an output waveform and easily apply an insulating resin for insulating a coil. In addition, the amount of applied insulating resin may be reduced, and sufficient insulation characteristics may be further achieved.