Integrated Multi-Stage Hook and Claw Compressor Layout

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Solution Overview

Problem

Traditional multi-stage hook and claw compressors have a large footprint due to separate airends and bull gear systems, increasing cost, complexity, and maintenance requirements.

Innovation Solution

A multi-stage compressor assembly with a single housing containing two airends, driven by parallel shafts with intermeshing gears, and a partitioning wall to separate stages, reducing overall size while maintaining performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional multi-stage compressors use separate airends and bull gear systems, then each stage can be independently designed and maintained, but the footprint and overall size increase significantly

Engineering Contradiction:
ImproveIndependent design and maintenance of stagesVSAvoidFootprint
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent combines two separate airends into a single integrated compressor housing, eliminating the need for separate housings and reducing the overall footprint. The first and second airends are merged within one housing structure, sharing common components while maintaining independent functional capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single compressor housing serves multiple functions by accommodating both the first and second airends, as well as integrating the bull gear system and drive unit. This multi-functional design reduces the number of separate components needed while maintaining the ability to independently design and maintain each compression stage.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of repair

If separate airends and bull gear systems are used, then maintenance access is easier for each stage, but the overall complexity and number of parts increase

Engineering Contradiction:
ImproveMaintenance access to stagesVSAvoidNumber of parts
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The patent merges the first and second airends into a single housing structure, reducing the total number of separate parts. However, it maintains maintenance accessibility by designing the integrated housing with features that allow easy access to both compression stages for servicing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

While the housing is integrated, the internal structure maintains segmentation between the first and second airends, allowing each stage to be independently accessed and maintained. The partitioning within the single housing enables separate maintenance access points for each compression stage.

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If a single housing with integrated airends is used, then the footprint is reduced, but the design complexity increases

Engineering Contradiction:
ImproveFootprintVSAvoidDesign complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent integrates multiple functional elements (first airend, second airend, bull gear system, drive unit) into a single housing, achieving footprint reduction. The design complexity is managed through systematic integration where each component is positioned to maintain its functional independence while sharing the common housing structure.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If traditional multi-stage compressors are used, then each stage operates independently with standard designs, but the overall cost increases due to multiple components

Engineering Contradiction:
ImproveStandardized stage designsVSAvoidTotal component count
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent reduces the total component count by merging the first and second airends into a single housing structure. This integration eliminates redundant components such as separate housings, mounting brackets, and isolation elements, while maintaining standardized designs for each compression stage.

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

The solution achieves a reduced footprint and package size without compromising performance, simplifying the design and reducing maintenance complexity.

Implementation Method 1

Compressors increase the pressure of a compressible fluid (e.g., air, gas, etc.) by reducing the volume of the fluid

Methodology Applied
Scientific EffectPositive displacement compression: Compression

Implementation Method 2

a cooling channel disposed within inner side wall of the compressor housing configured to circulate a coolant between the first airend and the second airend

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 3

an intercooler disposed between the first airend and the second airend, the intercooler configured to cool the working fluid prior to entering the second airend

Methodology Applied
Scientific EffectIntercooling: Heat Exchanger

Data Source

PatentEP4678919A1Multi-stage hook and claw compressor assembly
Publication Date: 2026.01.14 INGERSOLL RAND IND US INC
  • EP4678919A1 patent drawingFigure 1
  • EP4678919A1 patent drawingFigure 2
  • EP4678919A1 patent drawingFigure 3

AI summary

A multistage air compressor (100) configured to compress a working fluid is provided. The multistage air compressor comprises a single compressor housing (102) having a first airend (121) and a second airend (125). A drive unit (140) is configured to drive a first shaft (114) and a second shaft (116), the first shaft defining a first axis of rotation (114X) and the second shaft defining a second axis of rotation (116X), the first axis of rotation parallel to the second axis of rotation, the first shaft having a first end configured to be driven by the drive unit. The first airend (121) is operable to receive and compress the working fluid, the first airend including a first rotor (120) configured to be driven by the first shaft (114) and a second rotor (122) configured to be driven by the second shaft (116), where the first rotor and the second rotor define a first rotor pair (123). The second airend (125) is operable to receive the working fluid from the first airend (121) and further compress the working fluid, the second airend including a third rotor (124) configured to be driven by the first shaft (114) and a fourth rotor (126) configured to be driven by the second shaft (116), where the third rotor and the fourth rotor define a second rotor pair (127). The first rotor (120) and the third rotor (124) are disposed at a center distance from the second rotor (122) and the fourth rotor (126), respectively.