Scroll Compressor Axial Gap Design to Prevent Seizing

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Solution Overview

Problem

Existing scroll compressors face issues with seizing and decreased efficiency due to increased resistance and rotational moment between the fixed and orbiting scrolls, leading to reduced reliability.

Innovation Solution

The scroll compressor design includes an axial gap between the orbiting and fixed scroll surfaces, with one scroll having a higher hardness than the other, and the orbiting scroll end plate is pressed against a specific region of the fixed scroll, combined with surface treatments to enhance hardness differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If surface treatment is performed on one of the fixed scroll and orbiting scroll to prevent seizing, then reliability is improved, but resistance between the scrolls increases leading to decreased efficiency

Engineering Contradiction:

Improveseizing preventionVSAvoidresistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The invention applies different hardness levels to different regions of the scroll components. Specifically, the orbiting scroll is made with a harder material or surface treatment in the radial direction to prevent seizing, while maintaining softer properties in the axial direction to reduce resistance. This local differentiation of material properties resolves the contradiction between preventing seizing and minimizing energy loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention creates an asymmetric hardness distribution between the fixed scroll and orbiting scroll, where one scroll has higher hardness than the other in specific regions. This asymmetric design allows the harder scroll to resist seizing while the softer scroll reduces friction and resistance, thereby improving overall efficiency while maintaining reliability.

Inventive Principle:

Principle #4Asymmetry

2Reliability

If the orbiting scroll is hardened by surface treatment to prevent seizing, then reliability is improved, but the soft fixed scroll bottom surface wears rapidly causing increased resistance and potential seizing

Engineering Contradiction:

Improveseizing preventionVSAvoidwear resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The invention applies selective hardening to specific regions of the scrolls. The orbiting scroll is hardened in the radial direction where it contacts the fixed scroll wrap to prevent seizing, while the fixed scroll bottom surface maintains appropriate hardness to resist wear. This localized quality differentiation ensures both components have optimal properties for their specific functional requirements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of hardening the orbiting scroll uniformly, the invention inverts the approach by ensuring the fixed scroll has sufficient hardness to resist wear from the orbiting scroll's movement. This reversal of the conventional approach prevents the fixed scroll from wearing rapidly while still preventing seizing through controlled hardness differences in specific regions.

Inventive Principle:

Principle #13The other way round (Inversion)

3Loss of energy

If sliding resistance between scrolls is reduced to improve efficiency, then energy loss decreases, but seizing prevention capability is compromised

Engineering Contradiction:

Improvesliding resistanceVSAvoidseizing prevention

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The invention creates different surface properties in different regions of the scroll contacts. In regions where sliding occurs, the surfaces are treated to minimize friction and resistance. In regions where seizing prevention is critical, controlled hardness differences and surface treatments are applied to prevent adhesion and seizing. This spatial differentiation of surface qualities resolves the contradiction between reducing resistance and preventing seizing.

Inventive Principle:

Principle #3Local quality

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 prevents seizing, reduces rotational moment, and minimizes gas leakage, thereby improving efficiency and reliability.

Implementation Method 1

an orbiting scroll end plate is pressed against an outer peripheral wall of the fixed scroll in a region with angle of rotation larger than outer wall maximum involute angle of the fixed scroll

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

one or both of the fixed scroll and the orbiting scroll are subjected to a surface treatment, and one of the fixed scroll and the orbiting scroll has a higher hardness than the other

Methodology Applied

Scientific EffectSurface treatment: Anodising

Data Source

PatentEP4098877B1Scroll compressor

Publication Date: 2025.10.08 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

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AI summary

A scroll compressor has an axial gap between fixed spiral wrap (11b) and orbiting scroll bottom surface (12e) and between orbiting spiral wrap (12b) and fixed scroll bottom surface (11d), and is configured such that orbiting scroll end plate (12a) is pressed against outer peripheral wall (11c) of fixed scroll (11) in a region with angle of rotation larger than maximum involute angle of fixed scroll (11), and one of fixed scroll (11) and orbiting scroll (12) has a higher hardness than the other.