Motor Compressor Cover Recess Design for Vibration Control

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Solution Overview

Problem

Motor-driven compressors face challenges in reducing noise and size while maintaining durability, as existing designs either increase noise through vibration transmission or enlarge the compressor due to rib protrusions, which can lead to corrosion and weight issues.

Innovation Solution

The design incorporates a cover with a plate-shaped body wall featuring a first thickness portion and recessed second thickness portions around insertion holes, reducing vibration transmission and preventing foreign matter deposition, thus minimizing noise and size without enlarging the compressor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ribs protrude from the first surface toward the inverter to increase body wall rigidity, then vibration transmission to the cover is limited, but the accommodation chamber size is reduced and interference between ribs and inverter occurs

Engineering Contradiction:
Improvebody wall rigidityVSAvoidaccommodation chamber size
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

Instead of protruding ribs from the first surface toward the inverter, the patent inverts the approach by forming recesses in the first surface that extend toward the second surface. This inversion maintains the rigidity-enhancing function while eliminating space occupation in the accommodation chamber, thus preventing interference with the inverter and maintaining adequate chamber volume.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies local quality by creating recesses only in specific locations on the body wall where rigidity enhancement is needed, rather than using uniform rib structures across the entire surface. This localized approach optimizes structural strength while minimizing impact on accommodation chamber volume.

Inventive Principle:
Principle #3Local quality

2Volume of stationary object

If ribs protrude from the second surface to avoid interference with the inverter, then accommodation chamber size is maintained, but foreign matter deposition increases and corrosion resistance decreases

Engineering Contradiction:
Improveaccommodation chamber sizeVSAvoidcorrosion resistance
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The patent inverts the conventional rib protrusion approach by creating recesses in the first surface instead of protrusions on the second surface. This inversion prevents foreign matter accumulation while maintaining body wall rigidity, thereby improving corrosion resistance and overall reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the potential harm of surface irregularities into a benefit by designing recesses that are sealed and positioned to prevent foreign matter entry, rather than creating open protrusions that would trap contaminants and accelerate corrosion.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Strength

If the accommodation chamber is enlarged to avoid rib-inverter interference, then rib protrusion from the first surface is possible, but the cover and motor-driven compressor are enlarged in the axial direction

Engineering Contradiction:
Improvebody wall rigidityVSAvoidcompressor axial length
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The patent inverts the rib structure approach by using recesses instead of protrusions, which eliminates the need to enlarge the accommodation chamber. This allows the compressor to maintain a compact axial length while still achieving the desired body wall rigidity for vibration reduction.

Inventive Principle:
Principle #13The other way round (Inversion)

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 effectively reduces noise and weight while maintaining durability by absorbing vibrations and preventing corrosion, without compromising the accommodation chamber size.

Implementation Method 1

the rigidity of the body wall is increased by the ribs. This limits situations in which the vibration of the housing is transmitted to the cover

Methodology Applied
Scientific EffectVibration absorption: Damping

Data Source

PatentEP3647592B1Motor-driven compressor
Publication Date: 2022.11.30 TOYOTA INDUSTRIES CORP
  • EP3647592B1 patent drawingFigure 1
  • EP3647592B1 patent drawingFigure 2
  • EP3647592B1 patent drawingFigure 3

AI summary

A motor-driven compressor includes a compression mechanism, an electric motor, an inverter, a housing, and a cover defining an accommodation chamber with the housing to accommodate the inverter. The cover includes a plate-shaped body wall and insertion holes extending through a periphery of the body wall. The body wall includes a first surface opposed to the inverter in the accommodation chamber, a second surface, a first thickness portion having a first thickness, and a second thickness portion located around at least one of the insertion holes. The second thickness portion has a second thickness that is smaller than the first thickness and is obtained by recessing the body wall from the first surface toward the second surface.