Motor Stator Preheating With a Heat-Resistant Box and Mold

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Solution Overview

Problem

Existing methods for preheating unfinished stators for motors are inefficient, requiring lengthy heating times and complex facility structures, and often fail to uniformly preheat the mold used in molding processes.

Innovation Solution

A method involving the use of a heat-resistant box to conduct heat from coils to preheat the core, frame, and mold simultaneously, simplifying the preheating facilities and reducing heating time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If AC is turned on to the coils for preheating the unfinished stator, then the coils generate heat, but it takes a lot of time to heat the core uniformly from inner peripheral portion to outer peripheral portion

Engineering Contradiction:
Improveuniformity of temperature distributionVSAvoidpreheating time
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

A heat-resistant box filled with heat-resistant balls is introduced as an intermediary medium. The balls act as heat transfer mediators that receive heat from the coils and conduct it to the core, frame, and mold, achieving uniform temperature distribution more efficiently than direct coil heating alone.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the conventional direct electrical heating method with a hybrid system combining electrical heating (coils) and thermal conduction (heat-resistant balls). This substitution allows heat to be distributed more uniformly throughout the core and mold structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If a heater is provided to directly heat the outer peripheral portion of the core, then preheating time is shortened, but structures of preheating facilities become complicated

Engineering Contradiction:
Improvepreheating timeVSAvoidpreheating facility structure
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The heat-resistant box serves multiple functions: it contains the heat-resistant balls, supports the frame and mold during preheating, and acts as an insulating enclosure. This multi-functionality eliminates the need for separate heating devices for different components, simplifying the overall facility structure.

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

Solution Approach 2:

The invention merges the preheating function for the core, frame, and mold into a single integrated system using the heat-resistant box and balls. Instead of using separate heaters for each component, all elements are preheated simultaneously within the same enclosure, reducing structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the mold is excluded from preheating, then preheating facilities are simplified, but the mold must be heated separately before or during molding

Engineering Contradiction:
Improvepreheating facility structureVSAvoidmolding process efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The mold is preheated together with the core and frame in the heat-resistant box before the actual molding process. This preliminary heating of the mold ensures it is at the appropriate temperature when molding begins, eliminating the need for separate heating during production and improving overall efficiency.

Inventive Principle:
Principle #10Preliminary action

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 method allows for efficient and uniform preheating of the unfinished stator and mold in a short time, while simplifying the preheating facilities, thereby improving the overall efficiency of the process.

Implementation Method 1

turning on an alternative current to the coils in the heat-resistant box to cause the coils to generate heat

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

preheating the core, the frame and the mold for molding by the heat which is conducted from the coils

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4054063B1Method of preheating motor stator
Publication Date: 2025.02.19 TOYO DENKI SEIZO KK
  • EP4054063B1 patent drawingFigure 1
  • EP4054063B1 patent drawingFigure 2

AI summary

A method of preheating an unfinished stator 1 as an intermediate product before a stator as a final product for a motor is provided in order to preheat a mold 2 for molding together with the unfinished stator 1 in short time by using preheating facilities with simplified structures. In the method, the mold 2 has a hollow and longitudinal barrel portion 21 and a flange portion 22 extending outward from an end of the barrel portion 21. The flange portion 22 is arranged at a horizontal position to turn the barrel portion 21 upward and an end of a cylindrical and longitudinal frame 13 is put on the flange portion 22 in a state where a core 11 of the unfinished stator 1 is fitted in the frame 13. A heat-resistant box 5 of which an underside is opened covers the frame 13 and the mold 2 to surrounded outsides of the frame 13 and the mold 2. Alternative current is turned on to coils 12 in the box 5 to cause the coils 12 to generate heat. The core 11, the frame 13 and the mold 2 are preheated by the heat which is conducted from the coils 12.