Scroll Compressor Tip Seal Back-Pressure Design
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Solution Overview
Problem
In scroll compressors capable of three-dimensional compression, thermal deformation at the step portion leads to gas leakage due to narrowed gaps between the tip seal and the counterpart scroll member, causing performance deterioration and variation.
Innovation Solution
A back-pressure introducing portion with a larger gap between the back surface of the step-portion end of the tip seal and the groove bottom surface is provided, allowing back-pressure to enter the tip seal even during thermal deformation, ensuring the tip seal functions properly and preventing gas leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a step portion is provided on the spiral wrap to enable three-dimensional compression, then the compressor capacity is increased, but thermal deformation at the step portion causes gas leakage due to narrowed gaps between the tip seal and the counterpart scroll member
Solution Approach 1:
The patent applies local quality by providing a back-pressure introducing portion specifically at the step portion of the spiral wrap where thermal deformation occurs. This localized structure introduces back-pressure to the tip seal at the critical location, compensating for the narrowed gap caused by thermal deformation and maintaining sealing performance without affecting other areas of the compressor
2Volume of moving object
If the wrap height on the outer peripheral side is made higher than on the inner peripheral side to enable three-dimensional compression, then the displacement is increased, but the tip seal gap is narrowed due to thermal deformation
Solution Approach 1:
The patent applies preliminary anti-action by introducing back-pressure to the tip seal in advance through the back-pressure introducing portion. This pre-applied pressure counteracts the narrowing effect of thermal deformation on the tip seal gap, preventing gas leakage before it occurs and maintaining effective sealing despite the reduced gap dimension
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 solution stabilizes compression performance by maintaining the integrity of the tip seal on the outer peripheral side of the step portion, reducing gas leakage and enhancing the durability of the scroll compressor.
Implementation Method 1
When high-pressure gas flows into this gap, the upper end surface of the tip seal is deformed and brought into contact with the lower surface of the end plate of the other scroll part, so that a sealing in the axial direction can be obtained
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
An object of the present invention is to provide a scroll compressor capable of three-dimensional compression, which can prevent performance deterioration and performance variation due to gas leakage occurring on an outer peripheral side of a step portion of a spiral wrap and can achieve performance stabilization and performance improvement. In a scroll compressor configured to be capable of three-dimensional compression in a circumferential direction and a height direction of spiral wraps, in which top surfaces and bottom surfaces of spiral wraps (25B and 27B) are provided with step portions (25E and 27E) and the wrap height on the outer peripheral side of the step portion is made higher than the wrap height on the inner peripheral side, back-pressure introducing portions (55 and 57) where gaps between the back surfaces at step-portion ends of tip seals and groove bottom surfaces of tip seal grooves are made larger than a gap at the other portion are formed between the step-portion ends of tip seals (51 and 53) provided on top surfaces (25G and 27G) on the outer peripheral side of the spiral wraps and tip seal grooves (25L and 27L) to which the tip seals are fitted.