Stator Core Notch Configuration for Rotary Electric Machine
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Solution Overview
Problem
Conventional stator designs for rotary electric machines increase iron loss and decrease output torque due to deformation during notch formation and magnetic saturation, while requiring multiple types of electromagnetic steel sheets and press molds, leading to higher costs.
Innovation Solution
A stator core formed by rotating and stacking steel sheets with notches only on some tooth portions, using a single type of steel sheet and reducing the length of engagement recesses, which prevents iron loss and magnetic saturation without increasing the number of component types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If notches are formed on all tooth portions of all electromagnetic steel sheets, then engagement recesses can be formed for insulator attachment, but iron loss increases due to deformation during press molding
Solution Approach 1:
The invention applies local quality by forming notches only on specific tooth portions (e.g., every other tooth or selected teeth) rather than all tooth portions. This localized approach provides sufficient engagement recesses for insulator attachment while minimizing the total number of notches, thereby reducing deformation during press molding and lowering iron loss.
2Reliability
If engagement recesses are provided on both sides of each tooth, then insulators can be securely attached, but the tooth width is narrowed causing magnetic saturation and decreased output torque
Solution Approach 1:
The invention applies local quality by providing engagement recesses only on selected tooth portions rather than on both sides of every tooth. This selective placement ensures adequate insulator attachment reliability while preserving sufficient tooth width in other areas, preventing magnetic saturation and maintaining output torque performance.
3Power
If two different types of electromagnetic steel sheets are used to shift engagement recess positions, then magnetic saturation is reduced, but the number of component types and press molds increases
Solution Approach 1:
The invention applies local quality by using a single type of electromagnetic steel sheet with notches formed only on selected tooth portions. This approach achieves the same effect of reducing magnetic saturation and preserving tooth width as the two-type sheet approach, but simplifies manufacturing by requiring only one component type and one press mold.
Data Source
AI summary
A stator for a rotary electric machine includes a stator core including a stack of a plurality of steel sheets 36; a stator coil wound around teeth of the stator core; and a plurality of insulators interposed between the stator core and the stator coil. Each of the insulators has at least one engagement tab projecting toward a side surface of a tooth. Each of the steel sheets 36 has a plurality of tooth portions 40 that form the teeth when the steel sheets 36 are stacked. Each of some of the plurality of tooth portions 40 has a notch 42 formed on a side surface of the tooth portion 40, the notches 42 forming an engagement recess in which the engagement tab is hooked when the steel sheets 36 are stacked. The stator core is formed by rotating and stacking the plurality of steel sheets 36.