Stator End Piece Segmentation for Magnetic Flux Transfer

Solution Overview

Problem

Existing stators for electric motors in washing machines face challenges in optimizing the length ratio between the stator core and end pieces, which affects magnetic flux transfer and efficiency, and require innovative designs to enhance magnetic flux collection without increasing the stator core's thickness.

Innovation Solution

The stator design incorporates a stator core with a yoke and radially extending arms, where each arm has an end piece with a length greater than the stator core, and a polymeric shell is injection-molded over the core and end pieces, with a dovetail joint locking mechanism to secure the end pieces, allowing for improved magnetic flux transfer and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the stator core length is increased to improve magnetic flux transfer, then the magnetic flux collection is improved, but the overall thickness of the stator increases

Engineering Contradiction:

Improvemagnetic flux transfer efficiencyVSAvoidstator thickness

Core Design Contradiction:

Loss of energyVSLength of stationary object

Solution Approach 1:

The stator is divided into two independent components: the stator core and the end pieces. The end pieces are separately formed and then attached to the radial ends of the stator core arms. This segmentation allows the end piece length to be independently adjusted to match the permanent magnet length, optimizing magnetic flux collection without increasing the stator core thickness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of increasing the stator core length in the axial direction to improve magnetic flux transfer, the design extends the end pieces beyond the stator core ends in the radial direction. This dimensional change allows the end pieces to protrude axially beyond the stator core, providing extended magnetic flux collection path without increasing the overall stator package size.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of energy

If the end piece length is increased to match permanent magnet length for optimal flux collection, then magnetic flux transfer is improved, but the stator structure becomes more complex

Engineering Contradiction:

Improvemagnetic flux collection efficiencyVSAvoidstator structure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The stator is divided into two independent components: the stator core and the end pieces. The end pieces are separately formed and then attached to the radial ends of the stator core arms. This segmentation allows the end piece length to be independently adjusted to match the permanent magnet length, optimizing magnetic flux collection without increasing the stator core thickness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The design allows independent adjustment of the end piece length parameter to match the permanent magnet length. This parameter optimization enables maximum magnetic flux collection efficiency while maintaining a compact stator core structure, resolving the complexity issue by making the end piece a separately optimized component.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If the stator core and end pieces are formed as a single integrated component, then manufacturing is simpler, but the ability to independently optimize end piece length is lost

Engineering Contradiction:

Improvestator manufacturing simplicityVSAvoidend piece length adjustability

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The stator is divided into two independent components: the stator core and the end pieces. The end pieces are separately formed and then attached to the radial ends of the stator core arms. This segmentation allows the end piece length to be independently adjusted to match the permanent magnet length, optimizing magnetic flux collection without increasing the stator core thickness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The end pieces are pre-formed as separate components with optimized dimensions before being attached to the stator core. This preliminary formation allows for precise control of end piece length to match permanent magnet specifications, enabling optimal magnetic flux collection while maintaining manufacturing efficiency through specialized tooling for the separate components.

Inventive Principle:

Principle #10Preliminary action

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 magnetic flux transfer and maintains efficiency while keeping the stator core smaller, allowing for independent adjustment of end piece length to match the length of permanent magnets, improving flux collection without increasing the overall thickness, thus optimizing motor performance.

Implementation Method 1

This design enhances magnetic flux transfer and maintains efficiency while keeping the stator core smaller, allowing for independent adjustment of end piece length to match the length of permanent magnets, improving flux collection without increasing the overall thickness

Methodology Applied

Scientific EffectMagnetic flux transfer: Magnetic Field

Data Source

PatentUS9013086B2Stator for an electric motor including separately formed end pieces and associated method

Publication Date: 2015.04.21 WHIRLPOOL CORP

AI summary

A stator for an electric motor includes a stator core including a yoke and a plurality of arms extending radially from the yoke. The stator includes an end piece secured to a radial end of each arm of the stator core. The stator core has a length defined along a longitudinal axis of the stator, and each end piece has a length defined along the longitudinal axis of the stator. The length of each end piece is greater than the length of the stator core.