Stator Unit Assembly Using Welded Rotation-Stopping Member

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Solution Overview

Problem

Conventional stator units using thermoplastic resins for molding are prone to thermal deformation, leading to cracks and distortion, while thermosetting resins with low hardness, like urethane resin, result in fragile components and improper positioning of stator coils due to limitations in fixation methods.

Innovation Solution

The rotation-stopping member is embedded in the mold resin with projecting pieces that are bent and raised towards the yoke, allowing for welding and firm fixation, reducing the number of components and assembly time, and using a thermosetting resin like urethane for improved durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thermoplastic resin is used as mold resin, then the stator unit can be easily molded, but thermal deformation occurs leading to cracks and distortion

Engineering Contradiction:
ImprovemoldabilityVSAvoiddurability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the material parameter from thermoplastic resin to thermosetting resin with low hardness (urethane resin), which fundamentally alters the thermal and mechanical properties to prevent thermal deformation while maintaining moldability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining thermosetting resin (for durability and thermal stability) with metal components (rotation-stopping member and yoke) to achieve both ease of manufacture and high reliability

Inventive Principle:
Principle #40Composite materials

2Reliability

If thermosetting resin with low hardness is used as mold resin, then durability is improved, but fixation becomes difficult leading to improper positioning

Engineering Contradiction:
ImprovedurabilityVSAvoidfixation capability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the fixation function into two parts: the thermosetting resin provides embedding and positioning, while the separately formed metal projection provides mechanical interlocking and welding attachment, together solving the fixation problem

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The metal projection acts as an intermediary between the thermosetting resin and the yoke, enabling reliable fixation through welding while the resin provides the embedding medium

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional molding methods are used, then production is simple, but the number of components increases leading to complex assembly

Engineering Contradiction:
Improvemolding simplicityVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges multiple components into an integrated structure: the rotation-stopping member is formed as a single piece with the projection directly attached to the mold resin, eliminating the need for separate fixation components and reducing assembly steps

Inventive Principle:
Principle #5Merging (Combining)

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 configuration enhances the durability and reduces production costs by simplifying assembly, ensuring proper positioning of stator coils, and maintaining electrical connectivity to prevent high-voltage noise-induced discharge.

Implementation Method 1

the mold resin 59 is melted and then injected into the mold

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

injected into the mold, the outer periphery of the stator coils 50A and 50B is covered with and their internal gaps are filled with the mold resin 59

Methodology Applied
Scientific EffectInjection molding:

Implementation Method 3

when the mold resin 59 is hardened, the outer side of the stator coils 50A and 50B (the outer periphery and upper and lower portions thereof) is sealed

Methodology Applied
Scientific EffectHardening: Phase Change

Implementation Method 4

melted through ultrasonic welding or the like, and then crushed (bar-like portions 64 in a crushed state)

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP3754815B1Electric valve provided with a stator unit
Publication Date: 2024.06.05 FUJIKOKI CORP
  • EP3754815B1 patent drawingFigure 1
  • EP3754815B1 patent drawingFigure 2
  • EP3754815B1 patent drawingFigure 3

AI summary

Provided is a stator unit capable of reducing the number of components and man-hours of assembling so as to reduce parts cost and production cost, and a motor-driven valve including the same. A rotation-stopping member 30 includes an annular flat plate portion 31, three or more engagement pieces 37 for stopping rotation that are each provided in an engagement plate portion 35 that is bent from an inner periphery side of the annular flat plate portion 31 in a direction opposite to the side of the yoke 51, and three or more projecting pieces 39 that are bent and raised from the annular flat plate portion 31 toward the side of the yoke 51, the tip end portions of the projecting pieces 39 being joined through welding to the yoke 51.