Stator Winding Vibration Suppression via Rectangular Wire and Adhesive
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Solution Overview
Problem
Existing stators for rotary electric machines suffer from reduced space factor and insulation failures due to high expansion coefficient requirements for thermoplastic resins and thickness limitations of vibration-damping insulating materials, leading to rasping and magnetic noise.
Innovation Solution
A stator design with a three-layer adhesive structure, comprising an insulating layer and adhesive layers, is used between wire members and the stator core, with thermally expandable properties to maintain high space factor and prevent vibration, and a U-shaped adhesive configuration to enhance adhesion and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermoplastic resin is used to impregnate the insulating sheet between wire members and stator core, then the wire members are connected and adhered to the stator core, but the resin requires a very high expansion coefficient to be fully distributed between circular wire members, and wire members may contact the stator core causing insulation failure
Solution Approach 1:
The patent changes the geometric parameter of wire members from circular cross-section to rectangular cross-section. This parameter change allows the resin to be more effectively distributed and retained between adjacent wire members during the impregnation process, eliminating the need for high expansion coefficients and preventing direct contact between wire members and the stator core, thereby ensuring insulation reliability
Solution Approach 2:
The insulating sheet is designed with a porous structure that allows resin to penetrate and distribute evenly between wire members. The porous structure provides pathways for resin flow and ensures complete impregnation without requiring excessive expansion, solving the distribution adaptability problem
2Object-affected harmful factors
If an insulating sheet made of vibration-damping insulating material is interposed between the stator core and wire members to attenuate vibration, then vibration and noise are reduced, but the sheet requires certain thickness leading to lowering of the space factor
Solution Approach 1:
The patent employs a composite structure combining the insulating sheet with resin impregnation. The insulating sheet provides vibration-damping properties while the resin fills gaps and enhances adhesion. This composite approach achieves effective vibration attenuation with thinner material layers, preserving the space factor by eliminating the need for excessive sheet thickness
Solution Approach 2:
The resin acts as an intermediary material between the insulating sheet and wire members, enhancing the vibration-damping effect without requiring increased sheet thickness. The resin transfers and distributes vibrational energy more effectively, allowing thinner insulating sheets to achieve the same noise reduction performance
3Ease of manufacture
If the positions of wire members are not precisely controlled, then manufacturing is easier, but wire members are likely to contact the stator core causing insulation failure
Solution Approach 1:
The rectangular cross-section of wire members provides self-aligning geometry that guides proper positioning during assembly. The shape characteristics enable wire members to automatically orient themselves correctly in the slots, ensuring consistent spacing from the stator core without requiring complex positioning mechanisms or precise manual control, thus maintaining both ease of manufacture and insulation reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively suppresses vibration and noise by maintaining a high space factor and ensuring strong adhesion between wire members and the stator core, improving mechanical strength and reducing noise generation.
Implementation Method 1
an adhesive member (composed of an adhesive material or an adhesive layer) interposed between at least one straight portion among the plurality of straight portions accommodated in each slot and a surface of the slot to adhere the straight portion concerned to the stator core
Implementation Method 2
the adhesive member has a three-layer structure consisting of an insulating layer and adhesive layers laminated on both surfaces of the insulating layer
Data Source
AI summary
A stator core for a rotary electric machine is provided. The stator includes an annular stator core having a plurality of slots punched and arranged in the circumferential direction, being straight in the axial direction, and a stator winding consisting of wire members. The wire members have respective straight portions accommodated in respective slots. Each of the wire members has a conductor portion having a rectangular cross section and an insulating coating covering the conductor portion. An adhesive member is provided between each of the straight portions and the wall surface of each slot. In each slot, the adhesive member adheres the straight portions to the wall surface. Thus, the stator core can maintain the space factor of the wire members accommodated in each slot and suppress vibration of the wire members during the operation of the rotary electric machine to reliably reduce generation of peculiar noise or magnetic noise.