Laminated Rotor Core Preheating for Guide Member Insertion

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Solution Overview

Problem

The existing method for manufacturing laminated rotor cores faces challenges in accurately fitting a guide member into a shaft hole due to material thickness deviations and thermal expansion issues, leading to quality reduction and decreased productivity.

Innovation Solution

A method that involves preheating the core body before mounting and inserting permanent magnets, expanding the shaft hole diameter to facilitate smooth guide member insertion, and using a separable carrier tray to improve alignment and reduce forced insertion damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a minor gap is provided between the guide member and the shaft hole to facilitate smooth fitting, then the ease of operation is improved, but the manufacturing precision deteriorates due to thickness deviation and press-cutting accuracy issues

Engineering Contradiction:

Improveease of fitting guide memberVSAvoidaccuracy of shaft hole straightness and squareness

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies thermal expansion parameter changes by heating the core body before fitting the guide member. This increases the shaft hole diameter dynamically, allowing the guide member to fit smoothly even when the cold gap is minimal or negative, thus resolving the contradiction between ease of operation and manufacturing precision

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary heating of the core body before the guide member fitting operation. This preliminary thermal expansion creates sufficient clearance in advance, enabling smooth insertion without forcing and preventing damage to the shaft hole's straightness and squareness

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the carrier tray is reused repeatedly without sufficient cooling time, then the productivity is improved, but the ease of operation deteriorates as the guide member remains expanded and cannot be inserted

Engineering Contradiction:

Improvecarrier tray reuse efficiencyVSAvoidease of guide member insertion

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent performs preliminary heating of the core body before guide member insertion. This ensures that even if the carrier tray is hot from previous use, the core body's expanded state provides sufficient clearance for smooth guide member fitting, enabling rapid tray reuse without cooling delays

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent dynamically changes the thermal parameter of the core body by heating it before insertion. This temporary dimensional change allows the guide member to be inserted smoothly regardless of the carrier tray's temperature, thus maintaining high productivity without compromising ease of operation

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If forced insertion is attempted when the guide member does not fit smoothly, then the ease of operation is temporarily improved, but the reliability deteriorates due to potential damage or deformation of the core body

Engineering Contradiction:

Improveease of guide member insertionVSAvoidquality of laminated rotor core

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent changes the thermal parameter of the core body by heating it before insertion, which expands the shaft hole diameter and creates sufficient clearance. This eliminates the need for forced insertion, thereby maintaining both ease of operation and the reliability/quality of the core body without damage or deformation

Inventive Principle:

Principle #35Parameter changes

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 approach ensures smooth fitting of the guide member, reduces quality defects, and enhances productivity by maintaining expanded diameters during resin injection and curing, while allowing for efficient reuse of the carrier tray.

Implementation Method 1

a first preheating step of heating the core body before the mounting step, wherein the mounting step, the inserting step, and the injecting step are carried out in the stated order

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9768673B2Method of manufacturing laminated rotor core

Publication Date: 2017.09.19 MITSUI HIGH TEC INC

AI summary

There is provided a method of manufacturing a laminated rotor core, including: a mounting step of placing a core body on a carrier tray, the core body having a plurality of magnet insertion holes provided around the shaft hole, the carrier tray having a mount plate and a columnar guide member standing on a front surface of the mount plate 41, the placement of the core body being carried out by fitting the guide member into the shaft hole; an inserting step of inserting permanent magnets respectively in the magnet insertion holes; an injecting step of injecting a liquefied resin material in each of the magnet insertion holes; and a first preheating step of heating the core body before the mounting step, wherein the inserting step and the injecting step are carried out in a state in which the core body is placed on the carrier tray.