Stator Coil Corner Portion Design for Compact Electric Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotating electric machines used in automobiles face challenges in downsizing, particularly in reducing the height of coil ends in welded segments to fit within narrow spaces while maintaining clearance, as they tend to increase in size axially or radially.
Innovation Solution
The design incorporates a stator with a U-shaped segment coil configuration, where segment coils are connected using TIG welding or plasma welding, forming corner portions that reduce the size of the coil ends by creating a mountain-shaped welded portion with small surface tension, allowing for a larger connection area and reduced axial height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the height of the coil end in the welded portion of the segment coil is reduced to fit within narrow spaces, then the machine can be downsized and mounted in limited space, but the coil end will increase in size and project axially or radially
Solution Approach 1:
The connection portion is designed with a curved surface instead of a flat surface, creating a mountain-shaped welded portion. This curvature allows the weld to conform to the rounded geometry of the conductor end, reducing the need for flat surfaces and minimizing axial and radial projections while maintaining structural integrity and electrical connection.
Solution Approach 2:
The invention changes the geometric parameters of the connection portion by forming a mountain-shaped welded structure with specific curvature radius and height constraints. By controlling the shape parameters (curvature radius R1, R2 and height h within specified ranges), the design achieves compact coil ends that fit narrow spaces without excessive projection.
2Reliability
If segment coils are welded together to form stator coils, then electrical connection is achieved, but the welded portion increases in size and complicates the structure
Solution Approach 1:
The connection portion is designed with localized specific properties: a curved surface with defined curvature radius (R1 between 0.5-2.0 times the conductor width, R2 between 0.3-1.5 times the conductor width) and controlled height (h between 0.2-0.8 times the conductor width). This localized geometric optimization ensures reliable electrical connection while minimizing the overall size and complexity of the welded portion.
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 configuration effectively downsizes the coil ends, enhancing the machine's compactness and reliability while maintaining insulating characteristics, suitable for use in both electric vehicles and hybrid vehicles.
Implementation Method 1
segment coils being made of a conductor shaped into a rough U-shape and having a rectangular cross-section, the segment coil has at an end a connection portion connected to another segment coil
Data Source
AI summary
A rotating electric machine having downsized coil ends is provided. In a rotating electric machine having a stator 130 including a stator core 132 formed with a plurality of slots 420 rowed in a circumferential direction and a stator coil 138 inserted into the slots of the stator core, and a rotor 150 disposed rotatably with respect to the stator core with a clearance interposed therebetween. The stator coil is formed by a plurality of segment coils 28 being connected, the segment coils 28 being made of a conductor shaped into a rough U-shape and having a rectangular cross-section. The segment coil has at an end a connection portion 800 connected to another segment coil, the connection portion having a corner portion 810.