Package Fluid Machine Inverter Cooling Layout With Bottom Intake

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Solution Overview

Problem

The existing package-type fluid machines suffer from reduced cooling efficiency due to the separation of the inverter and cooling fan by the length of the motor, leading to a decrease in the flow rate of cooling air suctioned by the cooling fan.

Innovation Solution

The inverter intake ports are positioned below the inverters, and the cooling gas is suctioned from below to above, minimizing the separation distance from the cooling fan, thereby improving the cooling efficiency by ensuring a sufficient flow rate of cooling air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the inverter is disposed in an upper portion with respect to the compression portion and separated from the cooling fan by the length of the motor, then the component layout is simplified, but the flow rate of cooling air suctioned by the cooling fan is reduced and cooling efficiency decreases

Engineering Contradiction:
Improvecomponent layoutVSAvoidcooling efficiency
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The inverter is repositioned from a horizontal arrangement (separated by motor length) to a vertical arrangement directly above the compression portion. This dimensional change allows the cooling fan to be positioned closer to the inverter intake ports, improving cooling air flow rate while maintaining compact packaging.

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

2Adaptability or versatility

If the interval between the intake port and the cooling fan is made long to accommodate other components, then more components can be integrated in the package, but the cooling air flow rate is reduced

Engineering Contradiction:
Improvecomponent integrationVSAvoidcooling air flow rate
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent creates a localized cooling zone directly above the compression portion where the inverter is positioned. The cooling fan is specifically oriented to blow air upward into the inverter's intake ports, ensuring high-velocity cooling air delivery to the critical inverter components while maintaining short intake port-to-fan distance.

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If the cooling fan is positioned far from the inverter intake ports, then there is more space for other components, but the cooling efficiency of the inverter decreases

Engineering Contradiction:
Improveavailable spaceVSAvoidcooling efficiency
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The inverter housing and cooling air flow path are merged into a integrated structure. The inverter is positioned such that its intake ports are in direct communication with the cooling fan's output, creating a unified cooling system where the inverter housing itself serves as part of the cooling air passage.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances the cooling efficiency of the inverter and compression portion by maintaining a high flow rate of cooling air, optimizing the layout to reduce interference and improve space utilization.

Implementation Method 1

the cooling gas is suctioned from below to above, minimizing the separation distance from the cooling fan, thereby improving the cooling efficiency by ensuring a sufficient flow rate of cooling air

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

a package-type fluid machine in which the cooling efficiency of the inverter is improved... maintaining a high flow rate of cooling air

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3851672B1Package-type fluid machine
Publication Date: 2025.07.30 HITACHI IND EQUIP SYST CO LTD
  • EP3851672B1 patent drawingFigure 1(a)~1(c)
  • EP3851672B1 patent drawingFigure 2(a)~2(b)
  • EP3851672B1 patent drawingFigure 3(a)~3(c)

AI summary

A package-type fluid machine includes a compressor unit including a compression portion that compresses a fluid, a motor that drives the compression portion, and a cooling fan that is driven by the motor; a machine chamber in which the compressor unit is disposed; an inverter chamber which is adjacent to the machine chamber and in which an inverter is disposed; a partition wall that partitions off the machine chamber from the inverter chamber and has an opening; and an inverter intake port that is disposed in the inverter chamber to take in a cooling gas. The cooling fan is disposed on a side of the machine chamber, the opening being located on the side. The cooling fan is driven to cause the cooling gas to flow from the inverter intake port to the opening to cool the inverter.