Scroll Compressor Back Pressure Valve Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In scroll compressors, pressure fluctuations on the orbital edge plate surface cause abnormal vibrations in the back pressure valve, leading to unstable back pressure and efficiency issues, particularly during high-speed rotation.
Innovation Solution
A scroll compressor design featuring a crankshaft-driven orbiting scroll with a back pressure chamber and communication paths that adjust cross-sectional areas to maintain stable back pressure, using a back pressure control mechanism that opens and closes based on pressure differentials, ensuring the opening surface area of the back pressure chamber is equal to or smaller than the control side, thereby suppressing pressure fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the back pressure valve is directly exposed to pressure fluctuations on the orbital edge plate side surface, then the valve can respond to pressure changes, but abnormal vibrations occur and back pressure becomes unstable
Solution Approach 1:
The patent introduces an intermediary chamber between the orbital edge plate side surface and the back pressure valve. This intermediary chamber absorbs and dampens pressure fluctuations before they reach the valve, preventing abnormal vibrations while maintaining back pressure stability. The intermediary structure acts as a buffer that decouples the direct connection between the fluctuating pressure source and the sensitive valve mechanism.
2Quantity of substance
If the communication path cross-sectional area is large, then fluid flow is improved, but pressure fluctuations are transmitted more strongly to the back pressure valve
Solution Approach 1:
The patent applies local quality by creating different cross-sectional areas at different locations along the communication path. The communication path has a larger cross-sectional area near the orbital edge plate side surface to accommodate fluid volume, while having a smaller cross-sectional area near the back pressure valve to filter pressure fluctuations. This spatial variation in cross-sectional area allows the system to simultaneously handle both fluid transport and pressure stabilization functions.
3Reliability
If the orbital edge plate is used as an intermittent structure to block the back pressure valve inflow hole, then pressure fluctuation width at the valve decreases, but the valve remains vulnerable during high-speed rotation when fluctuations are large
Solution Approach 1:
The patent implements beforehand cushioning by pre-establishing a damping chamber and controlled communication path structure before pressure fluctuations reach the back pressure valve. This pre-configured cushioning structure is designed to handle pressure fluctuations across a range of rotation speeds, providing protective damping in advance rather than relying on intermittent blocking that may fail at high speeds.
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 stabilizes back pressure, reduces abnormal vibrations, and enhances the efficiency and reliability of the compressor by maintaining proper back pressure levels even under conditions of large pressure fluctuations.
Implementation Method 1
a back pressure control means for opening and closing the communication path by way of the pressure differential along the communication path
Implementation Method 2
configured so that the opening surface area of the back pressure chamber side of the inlet communication path on the back pressure chamber side is always equal to or smaller than the cross-sectional area of the inlet communication path on the back pressure control means side, by the base plate of the orbiting scroll always blocking part of the back pressure chamber side opening of the inlet communication path on the back pressure chamber side
Implementation Method 3
a crankshaft to mutually engage a stationary scroll having a whirlpool shape on the base plate and an orbiting scroll, and drive the orbiting scroll
Implementation Method 4
a suction chamber and a compression chamber formed between the orbiting scroll and stationary scroll by the orbital motion of the orbiting scroll accompanying the rotation of the crankshaft
Implementation Method 5
a back pressure chamber included in the back surface of the orbital scroll to apply a pressing force on the stationary scroll to the orbiting scroll by a pressure that is higher than the pressure in the suction chamber
Data Source
AI summary
A scroll compressor includes a crankshaft, a suction chamber, a back pressure chamber, a communication path, a back pressure control means, and a base plate. The base plate intermittently connects the communication path by opening and closing an opening on a back pressure chamber side of the communication path. The crankshaft drives an orbiting scroll, and mutually engages a stationary scroll having a whirlpool shape and the orbiting scroll.