Laminated Iron Core Heating Sequence to Limit Thermal Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for heating laminated iron cores result in deformation due to thermal expansion, such as warpage or undulation, as the inner and outer peripheral portions are heated simultaneously, lacking an escape for deformation.
Innovation Solution
A method involving N heating units aligned circumferentially, heating regions of the laminated iron core at different timings, with controlled switching operations to absorb thermal expansion by unheated regions, and optionally rotating the core or heating units to create heated and unheated areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the entire inner peripheral portion of the laminated iron core is heated substantially at the same time, then heating efficiency is improved, but deformation such as warpage or undulation occurs due to thermal expansion
Solution Approach 1:
The heating device divides the heating process into multiple segments by providing multiple heating units (first, second, third heating units) positioned at different locations. These heating units heat different regions of the laminated iron core at different times, preventing simultaneous heating of the entire inner peripheral portion. This segmentation approach maintains heating efficiency while avoiding uniform thermal expansion that causes warpage.
Solution Approach 2:
The heating units operate in a periodic sequence rather than simultaneously. The control unit activates heating units one after another in a predetermined sequence, creating a periodic heating pattern. This periodic action allows each heated region to expand into unheated regions, preventing accumulation of thermal stress and deformation while maintaining overall heating efficiency.
2Loss of time
If heating units are arranged to heat all regions simultaneously, then processing time is reduced, but deformation occurs due to lack of escape place for thermal expansion
Solution Approach 1:
The heating process is segmented into multiple sequential operations with multiple heating units working in rotation. Although not all regions are heated simultaneously (which would reduce processing time), the segmented approach with overlapping heating cycles maintains efficient processing while allowing thermal expansion escape paths in unheated regions.
Solution Approach 2:
The heating system dynamically adjusts which regions are heated at any given moment by sequentially activating different heating units. This dynamic approach creates moving boundaries between heated and unheated regions, providing continuous escape paths for thermal expansion while maintaining overall processing efficiency through rapid sequential heating.
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
Reduces deformation in the laminated iron core by providing escape paths for thermal expansion, effectively heating the core's surface while minimizing heat transfer to deep portions and joint areas, thus maintaining structural integrity.
Implementation Method 1
heating N regions of the laminated iron core that face the N heating units with the N heating units
Implementation Method 2
the inner peripheral portion tends to thermally expand outward in a radial direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for manufacturing a laminated iron core includes: arranging N heating units in the laminated iron core such that the N heating units are aligned in a circumferential direction of the laminated iron core, where N is a natural number of two or more; and heating N regions of the laminated iron core that face the N heating units with the N heating units. The heating includes switching operation of the N heating units from one to less than N at a time.