Resin-Filled Armature Core Structure for Constant Air Gap
Solution Overview
Problem
Existing armature molded structures face challenges in ensuring a constant air gap between the armature and rotor, leading to reduced torque and compromised resin filling properties, which affects the strength and efficiency of the motor.
Innovation Solution
The armature molded structure incorporates a cylindrical iron core with laminated first and second core sheets, where coupling and non-coupling portions are used to create an uneven surface for resin flow, allowing for improved resin filling and strength while maintaining a constant air gap, and protruding resin molded end portions facilitate resin flow into opening window portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If resin is poured into the magnetic pole tip portion to form an armature molded structure, then the strength of the armature is improved, but the air gap between the armature and rotor becomes non-constant leading to torque reduction
Solution Approach 1:
The magnetic pole tip portion is divided into multiple resin filling regions (first resin filling portion and second resin filling portion) separated by a non-resin-filled gap. This segmentation allows different portions of the magnetic pole tip to have different properties: some regions are reinforced with resin for strength, while others remain gap-free to maintain constant air gap for torque production.
Solution Approach 2:
Resin is selectively applied to specific regions of the magnetic pole tip portion rather than uniformly across the entire surface. The first and second resin filling portions provide localized reinforcement where structural strength is needed, while the non-resin-filled region maintains the original magnetic pole geometry for optimal torque characteristics.
2Force
If the air gap between armature and rotor is reduced to increase torque, then torque is improved, but resin filling properties deteriorate leading to poor strength
Solution Approach 1:
The air gap region is segmented into a non-resin-filled portion that maintains the constant air gap for torque production, and resin-filled portions that provide structural reinforcement. This allows the armature to have both the small air gap needed for high torque and the resin reinforcement needed for strength.
Solution Approach 2:
The resin is pre-formed into specific shapes (first and second resin filling portions) with predetermined geometries before being positioned in the magnetic pole tip portion. This preliminary formation allows the resin to be precisely placed in regions where it provides strength without interfering with the air gap geometry required for torque.
3Strength
If resin is filled into all portions of the magnetic pole tip, then armature strength is maximized, but the air gap becomes non-constant causing torque reduction
Solution Approach 1:
The magnetic pole tip portion is segmented into resin-filled regions and a non-resin-filled region. The first and second resin filling portions provide structural reinforcement, while the non-resin-filled region maintains the constant air gap geometry, thus preventing torque reduction despite extensive resin reinforcement.
Solution Approach 2:
Different regions of the magnetic pole tip have different properties: resin-filled regions for strength and a non-resin-filled region for maintaining air gap. This local differentiation allows the armature to simultaneously achieve maximum strength where needed and maintain optimal torque characteristics where required.
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
An armature molded structure includes a cylindrical iron core used for a molded structure of a motor armature; a winding; and molding resin, wherein the iron core includes first core sheets and second core sheets, the first core sheet includes first magnetic poles placed along a circumferential direction of the iron core, tip portions, on an inner peripheral side of the iron core, of adjacent first magnetic poles form a coupling portion coupling the adjacent first magnetic poles, the second core sheet includes second magnetic poles placed along the circumferential direction of the iron core, tip portions, on the inner peripheral side of the iron core, of adjacent second magnetic poles form a non-coupling portion separating the adjacent second magnetic poles, the first and second core sheets are laminated along a central axis direction of the iron core in such a manner that the coupling portions coincide with each other, the non-coupling portions coincide with each other, the coupling portion and the non-coupling portion coincide with each other, the winding is wound around the first and second magnetic poles of the laminated first and second core sheets, the first and second core sheets and the winding are molded with the molding resin, the non-coupling portion delimits an opening window portion in an inner peripheral surface of the iron core, and the opening window portion is filled with the molding resin.