Scroll Compressor Suction Hole Layout for Lower Suction Loss

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Solution Overview

Problem

Existing scroll-type fluid machines suffer from limited reduction in suction loss despite the use of grooves in the non-sliding region of the end plate to expand the cross-sectional area of the suction flow path.

Innovation Solution

The suction hole of the fixed scroll is arranged in a specific winding direction range where the orbiting scroll's wrap is on the outermost peripheral side, intermittently in direct communication with the working chamber, and is designed to overlap partially or not overlap with the working chamber and tip seal to minimize direct communication during certain crank angles, thereby reducing suction loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the suction hole is arranged to be in direct communication with the working chamber, then suction loss is reduced, but the tip seal may fall off due to increased stress

Engineering Contradiction:
Improvesuction lossVSAvoidtip seal retention
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The suction hole is positioned in a specific local region of the fixed scroll where the wrap of the orbiting scroll is on the outermost peripheral side between specific confinement start positions. This localized arrangement allows direct communication with the working chamber to reduce suction loss while avoiding regions where tip seal stress would be excessive

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The suction hole arrangement is designed in advance to overlap partially or not overlap with the working chamber and tip seal at certain crank angles. This preliminary configuration prevents excessive stress on the tip seal before it can cause failure, while still enabling direct communication during appropriate phases of operation

Inventive Principle:
Principle #10Preliminary action

2Loss of energy

If the cross-sectional area of the first suction flow path is expanded using a groove, then suction loss is reduced, but the effect is limited

Engineering Contradiction:
Improvesuction lossVSAvoidsuction efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

Instead of only expanding the cross-sectional area of the suction flow path in the radial direction using grooves, the invention positions the suction hole to enable direct communication with the working chamber along the axial dimension. This dimensional change allows gas to bypass the restricted flow path entirely during direct communication phases, significantly reducing suction loss and improving suction efficiency beyond what groove expansion alone can achieve

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

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 suction loss and prevents tip seal falling off by optimizing the communication between the suction hole and working chamber, enhancing sealing properties and reducing operational inefficiencies.

Implementation Method 1

A plurality of first working chambers are formed between the inner peripheral side of the wrap of the orbiting scroll and the outer peripheral side of the wrap of the fixed scroll... The first working chamber in the compression process compresses the gas

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

The first working chamber in the suction process sucks in gas through the suction hole of the fixed scroll and the first suction flow path

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP4678917A1Scroll-type fluid machine
Publication Date: 2026.01.14 HITACHI IND EQUIP SYST CO LTD
  • EP4678917A1 patent drawingFigure 1
  • EP4678917A1 patent drawingFigure 2
  • EP4678917A1 patent drawingFigure 3A~3B

AI summary

To provide a scroll-type fluid machine capable of reducing a suction loss. A scroll-type compressor includes: a fixed scroll 11 that has an end plate 17, a spiral-shaped wrap 18 erected on one surface of the end plate 17, and a suction hole 19 bored into the end plate 17; an orbiting scroll 12 that has an end plate 25 and a spiral-shaped wrap 26 erected on one surface of the end plate 25 so as to face the fixed scroll 11; and a driving shaft 13 that causes the orbiting scroll 12 to orbit relative to the fixed scroll 11. The suction hole 19 of the fixed scroll 11 is arranged in a winding direction range of the wrap in which range the wrap 26 of the orbiting scroll 12 is located on an outermost peripheral side relative to the wrap 18 of the fixed scroll 11 between a first confinement start position A and a second confinement start position B, and the suction hole 19 of the fixed scroll 11 is intermittently in direct communication with a working chamber 34 formed between an inner peripheral side of the wrap 26 of the orbiting scroll 12 and an outer peripheral side of the wrap 18 of the fixed scroll 11.