Rotary Machine Stator Segmentation for Flux Leakage Reduction

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Solution Overview

Problem

Existing electric machines, such as modulated pole machines, suffer from high leakage flux and high manufacturing costs, leading to decreased performance and efficiency.

Innovation Solution

A rotary machine design featuring a first and second stator core section with protruding teeth, a coil between them, and a rotor with permanent magnets, where the teeth of the second stator core section are circumferentially displaced relative to the first, and axially extending pole sections made of soft magnetic material, minimizing leakage flux and optimizing magnetic flux usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If modulated pole machine design is used, then torque output is high, but leakage flux increases and efficiency decreases

Engineering Contradiction:
Improvetorque outputVSAvoidleakage flux
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The stator core is divided into two separate stator core sections, each with its own set of teeth. This segmentation allows for optimized magnetic flux paths in each section while reducing leakage flux between poles, thereby maintaining high torque output while improving efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces an axial dimension to the flux paths by using two stator core sections stacked axially with circumferentially displaced teeth. This three-dimensional flux distribution reduces leakage flux while maintaining the high torque characteristics of modulated pole machines

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

2Power

If modulated pole machine design is used, then torque output is high, but manufacturing cost increases

Engineering Contradiction:
Improvetorque outputVSAvoidmanufacturing cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

Dividing the stator into two separate core sections allows each section to be manufactured independently using standard stamping and assembly processes, reducing overall manufacturing complexity and cost while maintaining the high-performance modulated pole structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circumferential displacement parameter between the two stator core sections is optimized to achieve the desired magnetic flux distribution and torque characteristics while using conventional manufacturing tolerances and standard component dimensions, keeping manufacturing costs manageable

Inventive Principle:
Principle #35Parameter changes

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 enhances torque production, reduces manufacturing costs, and allows for high electric loading and output, while enabling constant torque and efficient flux concentration, thus improving machine performance and efficiency.

Implementation Method 1

the magnetic flux from the permanent magnets and the coil may be more efficiently used

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

the coil often is easy to manufacture

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Implementation Method 3

axially extending pole sections made from soft magnetic material

Methodology Applied
Scientific EffectSoft magnetic material: Ferromagnetism

Data Source

PatentEP1929609B1An electric machine assembly
Publication Date: 2013.06.05 HOGANAS AB
  • EP1929609B1 patent drawingFigure 1~2
  • EP1929609B1 patent drawingFigure 3~4
  • EP1929609B1 patent drawingFigure 5~6

AI summary

An electrical, rotary machine, according to the invention may include a first stator core section being substantially circular and including a plurality of teeth, a second stator core section being substantially circular and including a plurality of teeth, a coil arranged between the first and second circular stator core sections, and a rotor including a plurality of permanent magnets. The first stator core section, the second stator core section, the coil and the rotor are encircling a common geometric axis, and the plurality of teeth of the first stator core section and the second stator core section are arranged to protrude towards the rotor. Additionally the teeth of the second stator core section are circumferentially displaced in relation to the teeth of the first stator core section, and the permanent magnets in the rotor are separated in the circumferential direction from each other by axially extending pole sections made from soft magnetic material.