Stator Coil End Height Reduction via Segmented Oblique Conductor Design
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Solution Overview
Problem
Existing stator designs for electric rotating machines face challenges in ensuring electrical insulation and minimizing size due to thermal degradation of insulating coats and complex manufacturing processes, particularly when reducing the angles between conductor segments and the stator core, which affects the distance between welds and the protruding height of the coil end.
Innovation Solution
A stator design featuring a hollow cylindrical core with U-shaped electric conductor segments, where each segment has an insulating coat-covered oblique portion formed in two parts with different angles, allowing for sufficient distance between joints for insulation and minimizing the coil end's protruding height, and using only the insulating coat-removed portions for welding to prevent thermal degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the angle between oblique portions and axial end face is reduced to minimize coil end protruding height, then the protruding height is reduced, but the distance between joints is reduced making it difficult to ensure electrical insulation
Solution Approach 1:
The oblique portion is divided into two separate parts: a first oblique portion extending from the axial end face, and a second oblique portion extending from the distal end of the first oblique portion. This segmentation allows the joint to be positioned at the distal end of the second oblique portion, maximizing the distance between adjacent joints while maintaining a compact overall profile.
Solution Approach 2:
Instead of using a single oblique portion at one angle, the invention introduces a two-stage oblique structure with different angles (first angle and second angle). This dimensional change in the geometric configuration allows optimization of both the protruding height and the joint spacing independently.
2Length of stationary object
If the angle between oblique portions and axial end face is reduced to minimize coil end protruding height, then the protruding height is reduced, but the insulating coats may be thermally degraded by welding heat
Solution Approach 1:
By segmenting the oblique portion into two parts, the joint is repositioned to the distal end of the second oblique portion, which is farther from the axial end face. This increases the distance between the welding location and the insulating coats on adjacent conductor segments, reducing thermal degradation during welding operations.
3Ease of manufacture
If insulating coats are removed from oblique portions for welding, then electrical connection is achieved, but thermal degradation of insulating coats occurs
Solution Approach 1:
The insulating coat is selectively removed only from the distal end of the second oblique portion where the joint is formed, rather than from the entire oblique portion. This extraction approach allows welding to proceed while preserving the insulating coats on the main body and first oblique portion, preventing thermal degradation.
4Reliability
If complex manufacturing processes with special jigs are used to ensure insulation, then electrical insulation is ensured, but device complexity increases
Solution Approach 1:
The segmented oblique portion structure inherently provides sufficient distance between joints through its geometric configuration alone, eliminating the need for complex manufacturing processes, special jigs, or additional insulation measures. The design itself ensures electrical insulation.
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
This design ensures reliable electrical insulation and minimizes the stator's size by maintaining adequate distance between joints and reducing thermal degradation, simplifying the manufacturing process by eliminating the need for additional spaces and special jigs.
Implementation Method 1
Each of the electric conductor segments has an insulating coat covering an outer surface of the electric conductor segment... the insulating coats that cover those oblique portions of the electric conductor segments may be thermally degraded by the heat input for the formation of the joint by welding
Implementation Method 2
each corresponding pair of the insulating coat-removed portions of the electric conductor segments, which are radially adjacent to each other, are joined, for example by welding, to form a joint therebetween
Data Source
AI summary
A stator includes a stator core and a stator coil comprised of a plurality of electric conductor segments mounted on the stator core. Each of the electric conductor segments has an insulating coat-removed portion. Each corresponding pair of the insulating coat-removed portions of the electric conductor segments are joined with a joint formed therebetween. Each of the electric conductor segments also has an oblique portion that is comprised of a first part and a second part. The first and second parts extend, along the circumferential direction of the stator core, obliquely with respect to an axial end face of the stator core respectively at first and second oblique angles θ1 and θ2, where θ2>θ1. The second part is positioned closer to the joint, where the insulating coat-removed portion of the electric conductor segment is jointed to that of another electric conductor segment, than the first part is.