Electric Rotating Machine Stator Winding Insulation
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Solution Overview
Problem
There is a demand to reduce the size and enhance the performance of electric rotating machines for hybrid vehicles while ensuring high insulating performance, which is challenging due to the need for thicker insulating resin members that increase material costs.
Innovation Solution
The electric rotating machine design includes a stator winding with conductor segments having specific in-slot portions, coil end sections, and joint-side end portions with a skew portion, where the insulating resin member is thicker over conductor exposed portions for improved insulation, reducing material usage and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the insulating resin member is increased to ensure high insulating performance, then the insulating performance is improved, but the material cost increases
Solution Approach 1:
The insulating resin member is designed with non-uniform thickness, being thicker at the joint area where conductor exposed portions are joined and thinner at other areas. This local quality variation ensures high insulating performance at the critical joint area while reducing material usage and cost in non-critical areas.
Solution Approach 2:
The insulating resin member is segmented into different thickness zones: a first thickness at the joint area covering conductor exposed portions and a second thickness at other areas. This segmentation allows optimized insulation where needed while minimizing material cost overall.
2Productivity
If the size of electric rotating machines is reduced to meet hybrid vehicle requirements, then the productivity and efficiency are improved, but the insulating performance becomes more difficult to ensure
Solution Approach 1:
By concentrating the insulating resin thickness at the joint area where insulation is most critical, the design achieves high insulating performance in a compact overall structure, enabling reduced machine size without compromising reliability.
Solution Approach 2:
Instead of uniformly increasing insulation throughout, the design applies excessive insulation only where necessary (joint area with conductor exposed portions) and minimal insulation elsewhere, achieving sufficient insulating performance in a compact design.
Data Source
AI summary
The electric rotating machine includes a stator winding constituted of conductor segments each having a pair of in-slot portions and a coil end section projecting from both axial ends of a stator core. The coil end section includes a joint-side end portion having a skew portion intersecting with another one of the conductor segments at an axial end of the stator core. The skew portion is formed with a joint end portion at an extremity thereof, the joint end portion being formed with a conductor exposed portion where an inner conductor is exposed and joined to a conductor exposed portion of another conductor segment. A joint area between the joint end portions and a vicinity thereof are covered by an insulating resin member. The insulating resin member is thicker at a portion covering the conductor exposed portions than at a portion covering other than the conductor exposed portions.