Scroll Compressor Pressure Keeping Mechanism for Startup Stability
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Solution Overview
Problem
Scroll type fluid machines face challenges in preventing rattling of the orbiting scroll during startup, which can lead to reduced lifespan due to contact and wear, especially when the pressure between the orbiting and fixed scrolls is insufficient to maintain stable operation.
Innovation Solution
A pressure keeping mechanism is implemented downstream of the discharge port, allowing the flow path area to change between two levels: a small area until a predetermined pressure is reached, and then increasing to a large area, ensuring stable orbiting of the scroll and reducing contact and wear by swiftly increasing pressure in the compression chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure between orbiting and fixed scrolls is not high enough at startup, then the orbiting scroll rattles and contacts the fixed scroll, but increasing pressure quickly may cause thermal expansion issues or require complex control mechanisms
Solution Approach 1:
The bypass passage is pre-configured in the discharge plug to automatically regulate pressure buildup in the compression chamber before main discharge occurs. This preliminary pressure regulation prevents rattling at startup without requiring external control systems
Solution Approach 2:
The compression chamber's own pressure serves to prevent rattling by pushing the orbiting scroll away from the fixed scroll through the bypass passage. The system uses its own operating pressure for protection rather than requiring external pressure sources
2Speed
If a bypass passage with small flow path area is provided in the discharge plug, then pressure in the compression chamber increases quickly to prevent rattling, but the flow path area must be carefully controlled to maintain stability
Solution Approach 1:
The discharge plug has different flow path characteristics in different locations: a small flow path area in the bypass passage for rapid pressure buildup, and a larger main discharge passage for stable operation. This local differentiation of flow path qualities resolves the contradiction between speed and stability
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 the orbiting scroll at startup, prevents rattling, and enhances the lifespan of the scrolls by utilizing the pressure in the compression chamber to maintain a stable orbiting operation without the need for additional components, keeping the compressor compact and efficient.
Implementation Method 1
a flow path area of a pressure keeping mechanism provided downstream of a discharge port can be changed to at least two levels, a small flow path area is set until a pressure upstream of the pressure keeping mechanism reaches a predetermined upstream pressure
Data Source
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AI summary
A pressure keeping mechanism is provided downstream of a discharge port of a compressor. The pressure keeping mechanism is set to a small flow path area having only a bypass orifice until a pressure in a downstream pipe reaches a predetermined pressure after the operation is started, the pressure keeping mechanism is set to a large flow path area of a pressure keeping valve which is opened when the pressure exceeds the predetermined pressure and the bypass orifice, thereby changing the flow path area at least in two stages. The pressure in the upstream pipe which is almost closed by the pressure keeping valve can be thus increased at a dash and the pressure in a compression chamber can also be increased swiftly immediately after the compressor is started.