Stator Tooth Projections for Insulation and Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stators face challenges in increasing clearance and creepage distances to prevent short circuits in polluted environments without compromising performance, torque, and noise generation, as conventional methods are either costly, complex, or detrimental to motor efficiency.
Innovation Solution
The stator design features projections on adjacent teeth forming a radially inward free contact surface, allowing for increased clearance and creepage distances without altering installation space, and these projections aid in insulation material flow and encapsulation, reducing overspray and improving slot filling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the clearance and creepage distances are increased to prevent short circuits in polluted environments, then the reliability is improved, but the device complexity and manufacturing cost increase due to larger stator dimensions or additional protective measures
Solution Approach 1:
The patent applies local quality by adding projections only at specific locations (radial outer edge sections of teeth) where insulation is most needed, rather than uniformly increasing the entire stator size. This localized approach increases clearance and creepage distances at critical points while maintaining compact overall dimensions and avoiding unnecessary complexity
Solution Approach 2:
The patent utilizes the circumferential dimension by adding projections that extend in the circumferential direction at the radial outer edge sections of teeth. This dimensional approach increases insulation distance without requiring radial or axial expansion, thereby maintaining compact stator dimensions while improving reliability
2Reliability
If cover slides are used to increase clearance and creepage distance, then the reliability is improved, but the manufacturing complexity and thermal performance worsen due to large overlaps and laborious processes
Solution Approach 1:
The patent segments the insulation function by integrating projections directly into the stator teeth structure, rather than using separate cover slide components. This segmentation eliminates the need for additional overlapping parts and simplifies the manufacturing process while maintaining the reliability benefits of increased clearance and creepage distances
Solution Approach 2:
The patent merges the insulation function with the existing stator tooth structure by forming projections as integral parts of the teeth. This merging eliminates the need for separate cover slides and their associated complex manufacturing processes, while still achieving the required clearance and creepage distances
3Reliability
If the stator is completely encapsulated to protect from environmental influences, then the reliability is improved, but the manufacturing complexity and cost increase due to complex encapsulation processes
Solution Approach 1:
The patent applies local quality by providing projections only at the radial outer edge sections of teeth where environmental exposure and contamination risks are highest. This localized insulation approach provides adequate protection against environmental influences without requiring complete stator encapsulation, thereby reducing manufacturing complexity and cost
4Reliability
If the slot opening width is increased to allow more insulation material, then the clearance and creepage distance is improved, but the motor cogging torque deteriorates leading to increased noise
Solution Approach 1:
The patent utilizes the circumferential dimension by adding projections that extend in the circumferential direction at the radial outer edge sections. This approach increases the effective insulation distance without requiring increased slot opening width, thereby maintaining optimal motor performance and minimizing cogging torque and noise while still achieving the required clearance and creepage distances
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a stator of an electric motor having teeth distributed in the circumferential direction and extending in the radial direction and grooves respectively provided between the teeth, wherein respectively adjacent teeth each form a groove opening at the radial outer edge sections of said adjacent teeth, and the radial outer edge sections of the teeth each have a projection extending into the groove opening in the circumferential direction and each forming a free contact surface directed radially inward.