Stator Winding Terminal Connection Structure for Compact Rotating Electric Apparatus
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Solution Overview
Problem
Conventional rotating electric apparatuses face challenges in achieving a balance between compact size, high output, and reduced noise, particularly in distributed winding arrangements, where coil overlap leads to larger sizes and performance limitations.
Innovation Solution
The proposed solution involves a rotating electric apparatus with a stator winding configuration where each pair of coils has one terminal led out from a top-side slot and the other from a bottom-side slot, with a coil terminal connection structure that bends the joint parts close to the coil end, allowing for reduced coil height and size optimization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a distributed winding arrangement is adopted to reduce noise, then noise is restricted within a substantially sinusoidal range, but the volume of the stator becomes larger due to significant coil overlapping at coil end position
Solution Approach 1:
The patent applies dimensional change by transitioning from a conventional planar coil arrangement to a three-dimensional folded coil structure. The coil wire is folded back on itself within the slot, creating multiple layers that extend in the radial direction. This allows the coil to occupy space more efficiently in the radial dimension rather than requiring excessive axial space for overlapping coil ends, thereby reducing stator volume while maintaining the distributed winding configuration needed for noise reduction.
Solution Approach 2:
The patent implements nesting by placing multiple coil layers within the same slot space. The coil wire is folded back and nested within the slot, with inner layers contained within outer layers. This nested arrangement allows the coil to achieve the required turns and length without extending the coil end significantly beyond the slot opening, thus reducing the overall stator volume while preserving the distributed winding topology for acoustic performance.
2Volume of stationary object
If a concentrated winding arrangement is used to reduce stator size, then coil end volume is reduced, but the rotating magnetic field becomes unevenly distributed causing increased noise due to harmonics
Solution Approach 1:
The patent applies local quality by implementing different winding characteristics in different regions of the stator. The distributed winding arrangement is maintained in the active region (where coils interact with the rotor magnetic field) to ensure even magnetic field distribution and reduce harmonic noise. Meanwhile, the coil end region is optimized with a compact folded structure that minimizes volume without affecting the magnetic field quality in the active region. This localized optimization allows simultaneous achievement of small size and low noise.
3Productivity
If copper element wire with rectangular cross section is used to increase coil space factor, then productivity is enhanced and size is reduced, but manufacturing complexity increases due to alignment requirements in distributed winding
Solution Approach 1:
The patent applies preliminary action by pre-forming the copper element wire with a rectangular cross-section and predetermined geometric characteristics before the winding process. The wire is prepared in advance with specific dimensional tolerances and structural features that facilitate automatic alignment during coil formation. This pre-preparation eliminates the need for complex real-time alignment mechanisms during winding, thereby maintaining high productivity while managing manufacturing complexity through advance preparation.
Solution Approach 2:
The patent utilizes parameter changes by optimizing the geometric parameters of the rectangular copper element wire, such as its cross-sectional dimensions, aspect ratio, and surface characteristics. By carefully selecting and controlling these parameters, the wire achieves optimal packing density and alignment properties that simplify the winding process. The parameter optimization allows the rectangular wire to be easily positioned and aligned in the distributed winding configuration without requiring complex manufacturing equipment or procedures, thus enhancing productivity while controlling complexity.
Data Source
AI summary
Each pair of coils mutually connected in a stator winding is arranged in a fashion that a first coil of each pair of coils has an inner-circumferential-side coil terminal (212) led out from an inner-circumferential-side slot position in the direction of a coil end (220) of the stator winding, and that a second coil of each pair of coils has an outer-circumferential-side coil terminal (211) led out from an outer-circumferential-side slot position in the direction of the coil end (220) of the stator winding for connection to the inner-circumferential-side coil terminal (212), wherein there is provided a coil terminal connection structure in which the inner-circumferential-side coil terminal (212) is connected to the outer-circumferential-side coil terminal (211) across the coil end (220), and joint parts (211a, 212a) thereof are bent close to the coil end (220).