Rotor Core Welding Suppresses Steel Sheet Radial Displacement
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Solution Overview
Problem
In rotary electric machines, the radial displacement of electromagnetic steel sheets above an annular recessed portion on the shaft can cause interference with the stator, as existing fixing structures fail to adequately restrict their movement.
Innovation Solution
The electromagnetic steel sheets are joined to form an integral body by welding, with the welding extending over multiple sheets, restricting radial movement and preventing interference with the stator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If an annular recessed portion is formed on the shaft to reduce stress or relieve processing tools, then the stress concentration is reduced, but the electromagnetic steel sheets positioned above the recessed portion may be displaced in the radial direction causing interference with the stator
Solution Approach 1:
The rotor core is segmented into multiple electromagnetic steel sheets that are selectively joined. Specifically, two or more electromagnetic steel sheets positioned above the annular recessed portion are joined to adjacent electromagnetic steel sheets, creating a segmented reinforcement structure that prevents radial displacement while maintaining the stress-relieving benefits of the recessed portion.
Solution Approach 2:
Multiple electromagnetic steel sheets are merged into an integral body through welding at specific locations. The welding joins two or more electromagnetic steel sheets positioned above the recessed portion with adjacent sheets, creating a combined structure that resists radial displacement forces while allowing the recessed portion to maintain its stress-relieving function.
2Reliability
If electromagnetic steel sheets are joined by welding to form an integral body, then radial displacement is suppressed, but the manufacturing process becomes more complex
Solution Approach 1:
The welding operation is applied locally only where needed - specifically at electromagnetic steel sheets positioned above the annular recessed portion - rather than joining all sheets throughout the entire rotor core. This localized approach suppresses radial displacement at the critical area while minimizing the overall manufacturing complexity and welding volume.
Solution Approach 2:
Instead of joining all electromagnetic steel sheets in the rotor core, the invention applies partial action by joining only two or more sheets positioned above the recessed portion with adjacent sheets. This partial joining provides sufficient reinforcement to prevent radial displacement interference with the stator while reducing manufacturing complexity compared to complete joining.
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 effectively suppresses the radial displacement of electromagnetic steel sheets above the annular recessed portion, preventing interference with the stator core and ensuring stable operation.
Implementation Method 1
two or more of the electromagnetic steel sheets positioned above the annular recessed portion and other electromagnetic steel sheets are joined to each other so as to form an integral body
Data Source
AI summary
A rotor includes: a shaft provided with a flange which projects outward in a radial direction from an outer peripheral surface of the shaft; and a rotor core formed by laminating a plurality of electromagnetic steel sheets, the rotor core being fitted on the outer peripheral surface of the shaft such that an axial-direction end surface of the rotor core is in contact with the flange. An annular recessed portion is formed on the outer peripheral surface of the shaft at a portion adjacent to a surface of the flange on a side of the rotor core, and two or more of the electromagnetic steel sheets positioned above the annular recessed portion and other electromagnetic steel sheets are joined to each other so as to form an integral body.