Outdoor Unit Fan Motor Wire Guide to Prevent Lead Wire Breakage

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Solution Overview

Problem

The existing handling structure for lead wires in outdoor air-conditioning units is prone to breakage due to shear forces applied to the lead wires, particularly at the root portion where the lead wire is tensioned without any loose sections, leading to potential failure.

Innovation Solution

The introduction of a rightward-and-leftward direction guide piece with a guide groove that changes the wiring path of the lead wire from the upward-and-downward direction to the machine chamber, reducing shear forces by bending the lead wire in a direction opposite to the machine chamber, thereby minimizing tension and stress on the lead wire root portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the lead wire is led directly from the fan motor to the electrical component unit via the retaining portion, then the wiring path is simplified, but the lead wire is subjected to shear force and tension that may cause breakage

Engineering Contradiction:
Improvewiring path complexityVSAvoidlead wire reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a guide piece as an intermediary component between the fan motor and the retaining portion. This guide piece includes a guide groove that changes the wiring path direction, acting as a mediator to redirect the lead wire and eliminate shear forces. The guide piece is positioned at a specific location apart from the fan motor, serving as an intermediate structure that facilitates smooth wire transition without direct tension or shear stress on the lead wire root portion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs dimensionality change by introducing a guide groove that operates in a different spatial dimension. The guide groove changes the wiring path from a direct vertical path to a path that includes horizontal displacement. This dimensional transition allows the lead wire to be redirected smoothly, converting the force vector and eliminating shear forces that would otherwise act on the lead wire root portion.

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

2Strength

If the retaining portion is positioned obliquely below the lead wire lead-out portion, then the lead wire is secured firmly, but shear force is applied to the lead wire root portion

Engineering Contradiction:
Improvelead wire securing strengthVSAvoidlead wire resistance to breakage
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The guide piece serves as an intermediary between the lead wire lead-out portion and the retaining portion. It includes a guide groove that receives the lead wire and redirects it in a direction away from the fan motor. This intermediary structure ensures that the lead wire is firmly secured by the retaining portion while preventing shear forces from being transmitted to the lead wire root portion, as the guide groove changes the force direction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the lead wire is tensioned without loose portions, then the wiring is compact, but the lead wire is prone to breakage under shear force

Engineering Contradiction:
Improvewiring structure compactnessVSAvoidlead wire resistance to shear force
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The guide piece acts as an intermediary that maintains wiring compactness while protecting against shear force. The guide groove receives and redirects the lead wire, allowing the wiring to remain compact and tensioned without loose portions, while simultaneously changing the force direction to eliminate shear stress on the lead wire root portion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The guide groove introduces a dimensional change in the wiring path, redirecting the lead wire in a direction that maintains compactness while eliminating shear force. By changing the path in a different spatial dimension, the lead wire remains tensioned and compact, but the force vector is redirected to avoid shear stress on the root portion.

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

Data Source

PatentEP3348919B1Air-conditioner outdoor unit
Publication Date: 2019.08.14 MITSUBISHI ELECTRIC CORP
  • EP3348919B1 patent drawingFigure 1
  • EP3348919B1 patent drawingFigure 2
  • EP3348919B1 patent drawingFigure 3

AI summary

A fan motor support (30) includes a rightward-and-leftward direction guide piece (40) which projects in a direction of approaching a fan motor (20) from a lower intermediate transverse plate (35b) or an upper intermediate transverse plate (35a) extending across a pair of support columns (31) in a rightward-and-leftward direction at a position above or below the fan motor (20) in a vertical direction at a distance apart from the fan motor (20). The rightward-and-leftward direction guide piece (40) is formed so as to be opened in a direction opposite to a machine chamber (M) in a rightward-and-leftward direction and recessed in a direction toward the machine chamber (M). A rightward-and-leftward direction guide groove (43) which is configured to change a wiring path of the lead wire (25) of the fan motor (20) hooked thereto to a direction toward the machine chamber (M) from the upward-and-downward direction. Therefore, a highly reliable outdoor unit for an air-conditioning apparatus which prevents breakage of the lead wire (25) of the fan motor (20) can be provided.