Insulating Bobbin Structure to Prevent Stator Winding Cracks
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Solution Overview
Problem
Conventional electric rotating machines face issues with insulating bobbins cracking due to excessive stress when the stator coil is wound around the stator core.
Innovation Solution
The design includes a U-shaped insulating bobbin with specific abutting areas and middle inner wall surface portions that prevent tensile stress by maintaining spaces between the bobbin and stator core components, ensuring compression stress is applied instead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the stator coil is wound around the stator core through the intermediary of the first insulating bobbin and the second insulating bobbin, then the stator coil can be mounted on the stator core, but excessive stress is applied to the insulating bobbins causing cracks
Solution Approach 1:
The patent applies beforehand cushioning by providing a gap between the middle inner wall surface portion of the insulating bobbin and the tooth side surface portion of the stator core. This gap acts as a cushioning space that prevents excessive stress from being transmitted to the insulating bobbin during coil winding, thereby preventing cracks while still allowing the coil to be mounted through the insulating bobbin.
2Stability of the object's composition
If the insulating bobbin is fitted tightly onto the stator core to ensure stability, then the insulating bobbin is securely positioned, but stress concentration occurs during coil winding leading to breakage
Solution Approach 1:
The patent applies local quality by differentiating the contact characteristics at different locations of the insulating bobbin. The first and second abutting areas are designed to contact the stator core for positional stability, while the middle inner wall surface portion is deliberately separated by a gap to avoid stress concentration. This localized differentiation of contact properties ensures both stability and strength.
3Device complexity
If the insulating bobbin structure is simplified to reduce manufacturing complexity, then production is easier, but the bobbin becomes more susceptible to stress-induced cracks
Solution Approach 1:
The patent applies segmentation by dividing the inner wall surface of the insulating bobbin into distinct functional zones: first abutting areas, second abutting areas, and middle inner wall surface portions with gaps. This segmentation of the bobbin structure into zones with different contact properties allows it to withstand stress while maintaining a relatively simple overall design that doesn't require complex additional components.
Data Source
AI summary
An insulating bobbin to be mounted on a stator core has a tooth-endface facing portion that faces an endface portion, in an axial direction, of the tooth portion and a tooth-side-surface facing portion that faces a tooth side surface portion, in a circumferential direction, of the tooth portion; the tooth-side-surface facing portion has a first abutting area that abuts on the tooth side surface portion, a second abutting area that abuts on the tooth side surface portion at a more outer side in a radial direction than the first abutting area abuts thereon, and a middle inner wall surface portion that is situated between the first abutting area and the second abutting area and faces the tooth side surface portion via a space.