Electric blower using an electric motor using a plurality of stator cores and vacuum cleaner using this electric blower

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Solution Overview

Problem

The existing brushless DC motors for electric blowers, such as those used in stick-type vacuum cleaners, face reliability issues due to thermal and mechanical loads applied to the coils during the molding of resinous bridge portions between stator cores, which can degrade performance.

Innovation Solution

The configuration includes stator cores with spacers made of non-magnetic material, such as PBT, that press the stator cores against a frame, maintaining their position and preventing coil damage, while allowing for easier assembly and improved reliability by avoiding direct molding of the bridge portion over the coils.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If resinous bridge portions are molded between stator cores to connect and integrate them, then assemblability is improved, but thermal load and mechanical load are applied to the coil causing reliability degradation

Engineering Contradiction:
ImproveassemblabilityVSAvoidcoil reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The stator is divided into multiple independent stator cores that are not connected by molded bridge portions. Each stator core remains as a separate unit with coils wound thereon, eliminating the need for resinous bridge portions that would apply thermal and mechanical loads to the coils. This segmentation approach maintains assemblability while protecting coil integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A non-magnetic spacer is introduced as an intermediary component between stator cores to maintain their positional relationships without creating direct mechanical or thermal connections. The spacer prevents harmful loads from being transmitted to the coils while still achieving the integration function needed for assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If stator cores are divided into multiple segments to improve workability of coil winding, then coil workability is improved, but additional connection structures are required increasing device complexity

Engineering Contradiction:
Improvecoil workabilityVSAvoidstator structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The stator is segmented into multiple independent stator cores, allowing coil winding to be performed on each core separately with improved workability. The segmentation itself is the final structure - no additional bridge portions or connection structures are needed, as the stator cores function independently while maintaining their segmented configuration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The harmful connection function (molded bridge portions) is extracted from the stator structure. The stator cores are divided into segments for manufacturing convenience, but the connection function is removed entirely, replacing it with a simpler arrangement where cores are positioned using spacers rather than being permanently bonded together.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution enhances the reliability and assemblability of the motor by preventing load application on the coils and allowing for precise positioning of stator cores, improving the motor's operational stability and efficiency.

Implementation Method 1

spacers made of non-magnetic material, such as PBT, that press the stator cores against a frame

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a brushless DC motor is known as an electric motor for an electric blower using a battery as a power source

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3208914B1Electric blower using an electric motor using a plurality of stator cores and vacuum cleaner using this electric blower
Publication Date: 2019.11.06 TOSHIBA LIFESTYLE PROD & SERVICES CORP
  • EP3208914B1 patent drawingFigure 1
  • EP3208914B1 patent drawingFigure 2
  • EP3208914B1 patent drawingFigure 3A~3B

AI summary

An electric blower comprising: an electric motor; and a fan rotated by the electric motor, wherein the electric motor includes a stator, a rotor connected to the fan, and a frame accommodating the stator and the rotor, the stator includes a plurality of stator cores respectively having a core tooth portion facing the rotor, a coil portion attached to the stator core to form a magnetic pole at the core tooth portion, and a spacer inserted between the stator cores to press the stator cores against the frame, and the frame includes a regulation portion regulating position of the stator core pressed by the spacer.