Fixed Scroll Intake Opening Geometry for Simpler Casting

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Solution Overview

Problem

Conventional scroll compressors face limitations in design and manufacturing, particularly in creating efficient intake openings for refrigerant flow, which can lead to suboptimal compression performance and increased manufacturing complexity.

Innovation Solution

A fixed scroll compressor body with a central plate-like base and spiral scroll rib, featuring inward-protruding portions that create intake openings upon removal, allowing for efficient refrigerant flow and compression, and a method of casting and machining that eliminates the need for core inserts in the mold, simplifying the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional casting methods with core inserts are used to create intake openings, then the intake openings can be formed in the scroll compressor body, but the manufacturing complexity and cost increase due to the need for core inserts and additional assembly steps

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcasting process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent removes the core insert from the casting process entirely. Instead of inserting a core to form the intake opening cavity, the design allows the intake opening to be formed directly in the outer wall of the scroll compressor body through the casting mold itself, eliminating the need for core insert removal and reducing manufacturing complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The casting mold is designed with the intake opening geometry pre-integrated into the mold cavity. The intake opening shape and position are predetermined in the mold design, allowing direct formation of the opening during casting without requiring subsequent core insert operations or post-casting modifications

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the scroll compressor body is designed with integrated intake openings, then manufacturing complexity is reduced, but the design complexity of the casting mold increases

Engineering Contradiction:
Improveoverall system complexityVSAvoidmold design complexity
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The patent merges the intake opening formation function into the main casting mold cavity design. The mold cavity includes the outer wall geometry and the intake opening geometry as integrated features, allowing both to be formed in a single casting operation without requiring separate mold components or assembly steps

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If conventional designs are used, then manufacturing processes are well-established, but refrigerant flow efficiency is suboptimal due to inadequate intake opening design

Engineering Contradiction:
Improverefrigerant compression efficiencyVSAvoiddesign maturity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent optimizes the local geometry of the intake opening in the outer wall of the scroll compressor body. The opening is designed with specific dimensions, position, and shape characteristics that improve refrigerant flow into the compression chamber, enhancing compression efficiency while maintaining the overall proven design framework

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3699432B1Cast-in offset fixed scroll intake opening
Publication Date: 2023.11.29 BITZER KUEHLMASCHINENBAU GMBH
  • EP3699432B1 patent drawingFigure 1
  • EP3699432B1 patent drawingFigure 2
  • EP3699432B1 patent drawingFigure 3

AI summary

A scroll compressor comprises scroll compressor bodies disposed in a housing, the scroll bodies including a fixed scroll body and a moveable scroll body, the fixed and moveable scroll bodies having respective bases and respective scroll ribs that project from the respective bases, wherein the scroll ribs mutually engage, the moveable scroll body being movable relative to the fixed scroll body for compressing fluid; wherein the fixed scroll compressor body comprises: a scroll compressor body comprising: a central body portion having a plate-like base with a spiral scroll rib projecting axially therefrom, wherein the spiral scroll rib includes a volume between the spiraled ribs for the compressing of refrigerant, and wherein the spiral scroll rib spirals from a central region of the plate-like base to an outer wall of the central body portion; and a first intake opening in the outer wall, the first intake opening providing a path for a flow of refrigerant into the volume, the outer wall having a machined inner peripheral surface surrounding at least three sides of the first intake opening, the first intake opening including an unmachined axially-extending edge segment that defines a first side of the first intake opening, and further including an unmachined radially axially-extending segment that defines a second side of the first intake opening opposite the first side.