Variable Ellipticity Rectangular Wire Winding for Motor Slots
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Solution Overview
Problem
The challenge is to improve the space factor of rectangular wires in electric motor windings without reducing the flexibility of the wire, as changing the cross-sectional configuration from round to rectangular can lead to enamel coating stress and deterioration.
Innovation Solution
A winding structure for rectangular wires is developed where the ellipticity of the wire increases from inner to outer layers, matching the slot width dimensions to minimize gaps and stress, with a split-core system and adjustable ellipticity in each layer to optimize space factor and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the cross-sectional configuration of round wire is changed to rectangular wire to improve space factor, then the space factor increases, but the flexibility of the wire deteriorates due to enamel coating stress
Solution Approach 1:
The patent applies local quality by making the ellipticity of rectangular wires vary across different layers of the coil. Inner layers have smaller ellipticity (closer to round shape) to maintain flexibility and reduce enamel coating stress, while outer layers have larger ellipticity to maximize space factor. This localized variation in geometric properties resolves the contradiction between flexibility and space utilization.
Solution Approach 2:
The patent changes the geometric parameter of ellipticity from a constant value to a variable value that differs by layer. By adjusting the ellipticity parameter systematically (smaller for inner layers, larger for outer layers), the patent simultaneously optimizes both flexibility (through smaller ellipticity where bending occurs) and space factor (through larger ellipticity in outer layers), resolving the technical contradiction.
2Quantity of substance
If the ellipticity of rectangular wire is increased to reduce gaps and improve space factor, then the space factor improves, but the enamel coating may become damaged due to increased stress
Solution Approach 1:
The patent applies local quality by differentiating the ellipticity value based on the wire's position in the coil structure. Inner layers that undergo bending have smaller ellipticity to protect enamel coating, while outer layers have larger ellipticity to fill gaps. This spatial differentiation of geometric properties simultaneously improves space factor and protects enamel coating integrity.
Solution Approach 2:
The patent employs beforehand cushioning by designing inner layers with smaller ellipticity values that act as a protective buffer. This reduced ellipticity in inner layers预先 reduces the stress on enamel coating during bending operations, preventing damage before it occurs, while still allowing outer layers to achieve high space factor with larger ellipticity.
Data Source
AI summary
In this winding structure for a rectangular wire, a coil is formed that is provided with: a core that forms a core main body; a teeth portion that is formed extending inwards in a radial direction from the core; and a jaw portion that is formed extending in a circumferential direction from a distal end on the inner side in the radial direction of the teeth portion, and in which a rectangular wire is wound in multiple layers around a slot that is formed surrounded by the teeth portion, the core, and the jaw portion. The ellipticity, which is a ratio of a width dimension relative to a thickness dimension of a cross-section of the rectangular wire, becomes larger as it is wound from inner layers of the coil towards outer layers thereof, and the ellipticity of the rectangular wire in each of the layers is set in accordance with the width dimension of the slot in each layer of the coil such that the generation of gaps between the slot and the rectangular wire is suppressed.