Stator Coil Radial Stacking for Axial Length Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing stator designs with coaxially wound coils experience an increase in axial length due to bent coil end portions, which can lead to an overall longer stator length, compromising efficiency and space utilization.

Innovation Solution

The method involves manufacturing stators with coaxially wound and wave wound coils, where the coils are inserted into slots with a larger circumferential clearance, allowing the coil end portions to be stacked radially without bending, thereby preventing axial length increase. This is achieved by adjusting the clearance between slot housed and slot housed portions, ensuring the coils are inserted with their conductor wires stacked radially, and using offset portions with specific width and angle configurations to prevent interference and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If coil end portions are bent radially inward to be stacked on each other in the axial direction, then coils can be housed in slots, but the axial length of the stator increases

Engineering Contradiction:
Improvecoil housing in slotsVSAvoidaxial length of stator
Core Design Contradiction:
Ease of manufactureVSLength of moving object

Solution Approach 1:

The patent changes the stacking direction of conductor wires from the axial direction to the radial direction. By having conductor wires stacked on each other in the radial direction rather than the axial direction, the coil end portions can be housed in slots without increasing the axial length of the stator, thus resolving the technical contradiction between ease of manufacture and axial length.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If conductor wires are stacked radially without bending coil end portions, then axial length is reduced, but clearance control between adjacent coils becomes critical

Engineering Contradiction:
Improveaxial length of statorVSAvoidclearance between slot housed portions
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent specifies precise parameter ranges for the clearance between slot housed portions of adjacent continuous coils. By controlling the clearance to be within a specific range (0.5 mm to 2.0 mm), the patent enables radial stacking of conductor wires without increasing axial length while maintaining manufacturability and preventing interference during assembly.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If offset portions are added to coil end portions, then interference between adjacent coils is prevented, but device complexity increases

Engineering Contradiction:
Improveprevention of coil interferenceVSAvoidcoil structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces offset portions only at specific locations (coil end portions) rather than modifying the entire coil structure. This localized modification prevents interference between adjacent continuous coils while maintaining the simplicity of the overall coil structure, thus resolving the contradiction between reliability and device complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3285366B1Stator and method of manufacturing stator
Publication Date: 2020.08.26 AISIN AW CO LTD
  • EP3285366B1 patent drawingFigure 1~2
  • EP3285366B1 patent drawingFigure 3~4
  • EP3285366B1 patent drawingFigure 5A~5B

AI summary

A stator is configured such that the clearance in the circumferential direction between a slot housed portion of a first continuous coil and a slot housed portion of a second continuous coil after the first continuous coil and the second continuous coil are housed in slots is larger than the clearance before the first continuous coil and the second continuous coil are housed in the slots.