Electric Rotating Machine Stator Conductor R-Chamfered Corner Design
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Solution Overview
Problem
Existing electric rotating machines face issues with insulating sheet members being torn at their axial ends due to the bending of electrical conductors, leading to insufficient insulation creepage distance between the stator core and winding.
Innovation Solution
The implementation of R-chamfered and flat C-chamfered portions on the electrical conductors, with curvature radii larger than the other corners, reduces the pressing force on the insulating sheet members, preventing tears by distributing the force more evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical conductors are bent to form skew portions at axial ends of the stator core, then the electrical conductors can be properly positioned and secured, but the insulating sheet member is likely to be torn at its axial end portions
Solution Approach 1:
The patent applies local quality by providing chamfered portions (R-chamfered or flat C-chamfered) at specific locations (radially inner and outer corners) of the electrical conductors where they bend to form skew portions. These localized structural modifications reduce pressing force only at the critical corners that contact the insulating sheet member, while maintaining the overall bending functionality of the conductors.
Solution Approach 2:
The chamfered portions are formed in advance on the electrical conductors before assembly into the stator slots. This preliminary action prepares the conductors to distribute pressing force more evenly during the subsequent bending process, preventing tear propagation in the insulating sheet member when the conductors are formed into skew portions.
2Reliability
If the insulating sheet member is folded into a square tube shape to fit the slot, then the insulation coverage is improved, but the axial end portions projecting from the stator core become vulnerable to tearing
Solution Approach 1:
The patent maintains the square tube folding of the insulating sheet member for comprehensive slot coverage but addresses the tear vulnerability through local quality modifications on the electrical conductors. The chamfered portions at the conductor corners reduce the pressing force concentration on the insulating sheet member's axial end portions, protecting them from tearing while preserving the folded structure's insulation effectiveness.
3Stability of the object's composition
If the electrical conductors are tightly secured in the slots, then the winding stability is improved, but the pressing force on the insulating sheet member increases causing potential tears
Solution Approach 1:
The chamfered portions provide localized stress relief at the critical corner regions where conductors contact the insulating sheet member, allowing the conductors to maintain tight securing and winding stability elsewhere while reducing concentrated pressing force that would cause tearing.
Solution Approach 2:
The patent modifies the geometric parameters of the conductor corners by creating chamfered portions with specific curvature radii (R-chamfered) or flat chamfer dimensions (flat C-chamfered). This parameter change transforms the corner geometry to distribute contact pressure more evenly, reducing the maximum pressing force on the insulating sheet member while maintaining overall conductor stability in the slots.
Data Source
AI summary
The electric rotating machine has the structure in which, for each one of the slots formed in its stator core, each of the innermost and outermost electrical conductors housed in the slot includes a R-chamfered portion formed in a bent portion thereof projecting outside from the slot and bent along a circumferential direction of the stator core. The R-chamfered portion is located at a radially inner or outer corner of the bent portion at which a side surface of the bent portion on the side being circumferentially bent intersects with a side surface of the bent portion on the radially inner or outer side. The R-chamfered portion is formed of a curved surface having a curvature radius larger than a curvature radius of the other three corners of the bent portion.