Three-Phase Stator Winding With Seamless Star-Parallel Bridges

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Solution Overview

Problem

Existing rotary electric machines for automotive applications face challenges in achieving high energy efficiency, specific performance, and compactness, while also being difficult to produce in an automated manner.

Innovation Solution

A three-phase stator winding design featuring a cylindrical tubular stator with salient magnetic poles, coils, and connection bridges that form a seamless circular shape, utilizing crimping forks for secure connections and insulating supports for stability and ease of assembly, allowing for high efficiency and adaptability to different nominal voltages without significant modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional stator winding designs are used, then manufacturing is simpler, but energy efficiency and specific performance are lower

Engineering Contradiction:
Improveenergy efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The stator winding is segmented into multiple independent coils distributed in slots, with each coil having defined starts and ends. This segmentation allows for optimized magnetic field distribution across different stator poles, improving energy efficiency while maintaining manufacturability through modular assembly procedures

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the stator winding are assigned different connection configurations. Specifically, coils associated with different poles have different connection patterns to external terminals, allowing local optimization of magnetic flux distribution and reducing parasitic effects, thereby improving overall energy efficiency

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If compact design is pursued, then dimensions and mass are reduced, but manufacturing automation becomes more difficult

Engineering Contradiction:
Improvemachine massVSAvoidautomated production capability
Core Design Contradiction:
Weight of moving objectVSExtent of automation

Solution Approach 1:

Coils are pre-assembled in the stator slots with their starts and ends positioned in predetermined locations before final connection. This preliminary arrangement of winding elements facilitates automated connection processes while achieving compact dimensions, as the complex positioning is done in a standardized preliminary step rather than during final assembly

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stator winding design uses universal connection patterns that can be applied across different pole configurations and machine sizes. The same basic coil structure and connection methodology serves multiple functions: creating magnetic fields, achieving compact packaging, and enabling automated assembly through standardized procedures

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Power

If high specific performance is achieved, then power density increases, but manufacturing precision requirements increase

Engineering Contradiction:
Improvespecific performanceVSAvoidwinding connection precision
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The winding is divided into discrete coils with clearly defined starts and ends, each associated with specific stator poles. This segmentation creates natural reference points for manufacturing, allowing high specific performance to be achieved through precise but manageable connection tasks rather than requiring overall winding precision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The same coil structure and connection pattern is replicated across multiple stator poles. This copying approach allows high specific performance to be achieved through standardized, repeatable manufacturing processes, reducing the impact of precision variations while maintaining high power density

Inventive Principle:
Principle #26Copying

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

The design achieves high energy efficiency, specific performance, and compactness, enabling the production of electric machines with reduced dimensions and mass, while being easily realizable in an automated production plant and adaptable to various voltage levels with minimal changes.

Implementation Method 1

a three-phase stator winding of a rotary electric machine... a generally permanent magnet rotor... and a stator arranged around the rotor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4336712A1Three-phase stator winding of a rotary electric machine
Publication Date: 2024.03.13 FERRARI SPA
  • EP4336712A1 patent drawingFigure 1
  • EP4336712A1 patent drawingFigure 2
  • EP4336712A1 patent drawingFigure 3

AI summary

Three-phase stator winding (12) of a rotary electric machine (1) and having: a plurality of coils (8) each of which has two opposite ends (10, 11); a plurality of first connection bridges (13), each of which defines a star connection of three coils (8) and constitutes a star centre of the three coils (8) by connecting a first end (10) of each of the three coils (8) to one another; and three second connection bridges (14, 15, 16) which define a parallel connection of the star connections, are each provided with a corresponding pin (17) defining a terminal of the three-phase stator winding (12) towards the outside, and each of which connects a second end (11) of a respective coil (8) of each star connection to one another. Each second connection bridge (14, 15, 16) has a seamless circular shape closed onto itself.