Stator Bobbin Coil Positioning for Uniform Resin Insulation
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Solution Overview
Problem
The insulating film and bobbin covering the coils in a rotating electric machine may be damaged due to vibration, leading to nonuniform resin distribution and potential dielectric breakdown from stress concentration.
Innovation Solution
A stator core with a bobbin having a through hole and protrusions to guide the position of coils, combined with a resin filling on the periphery of the coils, to uniformly distribute the resin and reduce stress concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the coils are inserted within the through hole of the bobbin without support structures, then the productivity and ease of assembly are improved, but the resin distribution becomes nonuniform and stress concentration occurs leading to dielectric breakdown
Solution Approach 1:
The patent introduces guide protrusions as intermediary structures that mediate between the coil and the bobbin. These protrusions guide the coil during insertion and maintain proper positioning, ensuring uniform resin distribution without requiring complex support structures, thus resolving the contradiction between assembly simplicity and reliability.
Solution Approach 2:
The guide protrusions perform preliminary positioning action during coil insertion. By guiding the coil into the correct position before resin injection, the structure ensures uniform resin distribution and prevents stress concentration, thereby improving reliability without compromising assembly productivity.
2Ease of operation
If the coils are allowed to move freely in the through hole, then the ease of insertion is improved, but the clearances between coils and bobbin become nonuniform causing resin formation issues and stress concentration
Solution Approach 1:
The guide protrusions act as intermediary elements that facilitate easy coil insertion while simultaneously ensuring precise positioning. The protrusions guide the coil along a predetermined path, maintaining uniform clearances between the coil and bobbin, thus resolving the contradiction between insertion ease and manufacturing precision.
3Object-affected harmful factors
If resin is filled to cover the coils and bobbin to suppress vibration damage, then the protection against vibration damage is improved, but the nonuniform resin distribution causes stress concentration and dielectric breakdown
Solution Approach 1:
The guide protrusions perform preliminary positioning of the coil before resin injection. This preliminary action ensures that when resin is filled to protect against vibration, the resin distributes uniformly around the coil, preventing stress concentration and dielectric breakdown while maintaining the protective function.
Solution Approach 2:
The guide protrusions mediate between the coil and resin filling process. By maintaining proper coil positioning during resin injection, the protrusions ensure uniform resin distribution, allowing the resin to effectively protect against vibration without causing stress concentration.
Data Source
AI summary
The present invention includes: a stator core (21) having a slot (21a); a bobbin (22) fitted in the slot (21a) and having a through hole (22c) penetrating in an axial direction of the stator core (21); a coil (23) inserted in the through hole (22c); a plurality of protrusions (22e) that protrude from at least one of an inner periphery of the through hole (22c) and an outer periphery of the coil (23), and guide the position of the coil (23) in the through hole (22c); and a resin filled on the periphery of the coil (23) in the through hole (22c).