Peripheral-Drive Fan Rotor Layout to Maintain Magnet Alignment

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Solution Overview

Problem

In motor-integrated fluid machines, the rotation of blades causes a displacement that offsets the magnetic poles relative to the windings, widening the gap between them and leading to a deterioration in motor performance and thrust.

Innovation Solution

A motor-integrated fluid machine design where the rotating portion includes blades with a center of gravity on the suction side, opposing the thrust, and magnets are positioned to face each other in the axial or radial direction, minimizing the displacement of the rotor and stator magnets and maintaining the thrust performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If blades are supported on a shaft portion with the tip side as a free end, then the blade structure is simplified and easier to manufacture, but the thrust causes displacement of the blade tip which offsets magnetic poles relative to windings and deteriorates motor performance

Engineering Contradiction:
Improveblade support structureVSAvoidmotor performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A counterweight is provided on the rotating support ring to generate a centrifugal force that opposes the thrust force acting on the blade. This counterbalancing mechanism prevents the displacement of the blade tip and maintains the proper alignment between magnetic poles and windings, thereby resolving the contradiction between simplified blade support structure and motor performance reliability

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Adaptability or versatility

If the gap between magnetic pole and winding is widened due to positional offset, then the motor structure becomes less constrained, but the motor performance deteriorates and thrust decreases

Engineering Contradiction:
Improvemotor structure flexibilityVSAvoidthrust generation
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The counterweight is positioned to generate a centrifugal force in advance that counteracts the thrust-induced displacement before it can cause significant offset between magnetic poles and windings. This preliminary counterbalancing action maintains optimal motor performance by preventing the harmful positional changes rather than correcting them after they occur

Inventive Principle:
Principle #9Preliminary anti-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 configuration suppresses the deterioration in motor performance by maintaining the alignment of magnetic poles and reducing the displacement of the rotor and stator magnets, ensuring stable thrust generation.

Implementation Method 1

The motor includes a rotor side magnet provided in the rotating support ring, and a stator side magnet provided in the outer peripheral portion to face the rotor side magnet

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

when blades rotate to generate thrust, the generated thrust acts on the blades

Methodology Applied
Scientific EffectThrust generation: Aerofoil

Data Source

PatentEP3889035B1Motor-integrated fluid machine and vertical take-off and landing machine
Publication Date: 2023.12.20 MITSUBISHI HEAVY IND LTD
  • EP3889035B1 patent drawingFigure 1
  • EP3889035B1 patent drawingFigure 2~3
  • EP3889035B1 patent drawingFigure 4

AI summary

This motor-integrated fan has a suction port and a blowing port, and is provided with: a rotating part rotatably supported on a shaft part; and a motor that rotates the rotating part. The motor is a peripheral drive motor that rotates the rotating part by applying motive power from a duct provided on an outer peripheral side of the shaft part. The motor includes: a permanent magnet provided on a rotation support ring connected to the outer peripheral side of a blade of the rotating part; and a coil provided facing the permanent magnet in the axial direction of a rotational axis. In a cross-section taken on a plane orthogonal to the circumferential direction of a rotational axis I, the center of gravity (point P2) of a free end side portion including at least one of the rotation support ring and the permanent magnet is positioned more to the suction port side in the axial direction of the rotational axis I than the center of gravity (point P1) of the thrust applied to the plurality of blades.