Scroll Compressor Injection Port Sealing via Localized Wrap Thickness
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Solution Overview
Problem
In scroll compressors with increased injection port diameters, communication between first and second compression chambers leads to refrigerant leakage, degrading efficiency, and increasing the orbiting-side wrap thickness to prevent leakage results in increased mass and cost.
Innovation Solution
A scroll compressor design featuring an orbiting-side wrap with a thick portion that covers the injection port, ensuring it does not communicate with both compression chambers simultaneously, while allowing increased injection flow rates without significant mass or cost increments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the diameter of the injection port is increased to increase the injection flow rate, then the injection flow rate is improved, but the injection port communicates with both the first compression chamber and the second compression chamber at the same time, causing refrigerant leakage and degradation of compressor efficiency
Solution Approach 1:
The orbiting-side wrap is designed with non-uniform thickness, specifically having a thicker portion at the location corresponding to the injection port. This local variation in thickness allows the wrap to effectively cover and seal the larger injection port when positioned there during orbital motion, preventing simultaneous communication between the first and second compression chambers while maintaining the benefit of the larger injection port diameter for increased flow rate
2Reliability
If the thickness of the orbiting-side wrap is increased to prevent communication between the first compression chamber and the second compression chamber, then refrigerant leakage is reduced, but the mass of the orbiting scroll increases, resulting in increased size and cost of the compression mechanism
Solution Approach 1:
Instead of uniformly increasing the thickness of the entire orbiting-side wrap, the invention applies increased thickness only at the specific location corresponding to the injection port. This localized thickening provides the necessary sealing capability to prevent refrigerant leakage between compression chambers while minimizing the overall mass increase of the orbiting scroll, thereby reducing size and cost increases
3Productivity
If the diameter of the injection port is increased, then the injection flow rate is improved, but the dimension of the opening of the injection port becomes larger, requiring larger wrap thickness to cover it completely
Solution Approach 1:
The orbiting-side wrap is designed with a thicker portion specifically at the location corresponding to the injection port, allowing complete coverage of the larger injection port opening. This localized thickness increase provides the necessary coverage without requiring a uniform increase in wrap thickness throughout, thus achieving the goal of covering larger ports while minimizing overall wrap dimensions and associated mass and cost increases
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A scroll compressor for intermediate injection has an injection port (55) located such that the injection port (55) communicates with a compression chamber (35a, 35b) immediately after a suction port thereof has been completely closed. An orbiting-side wrap (42) has a thick portion (45) including an increasing tooth thickness portion (45a) whose tooth thickness increases from the start of winding to the end of winding and a decreasing tooth thickness portion (45b) whose tooth thickness decreases from the increasing tooth thickness portion (45a) to the end of winding, thereby increasing the diameter of the injection port (55) in accordance with the thick portion (45). Thus, the injection flow rate can be increased, and degradation of efficiency of the compressor and increases in size and cost of a compression mechanism can be reduced.