Scroll Compressor Back-Pressure Chamber Segmentation
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Solution Overview
Problem
In scroll compressors, when the temperature inside the housing is lower than outside for a long period, liquid refrigerant accumulates in the back-pressure chamber, leading to excessive vaporization and increased pressure, which causes greater sliding resistance between the scrolls and the plate, resulting in inefficiency.
Innovation Solution
The design includes a discharge hole that connects the second back-pressure space to the suction pressure space, allowing refrigerant to be discharged from the back-pressure chamber, thereby reducing pressure and sliding resistance, and a back-pressure supplying groove that connects the first and second back-pressure spaces to urge the movable scroll toward the fixed scroll.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If liquid refrigerant accumulates in the back-pressure chamber due to temperature difference, then the refrigerant vaporizes and increases pressure, but this causes greater sliding resistance between the scrolls and the plate
Solution Approach 1:
The back-pressure chamber is divided into two separate spaces: a first back-pressure space between the movable scroll and opposed wall, and a second back-pressure space between the plate and back-pressure-chamber-defining recess. These spaces are connected by a back-pressure supplying groove, allowing pressure management in segmented zones to control refrigerant distribution and reduce sliding resistance.
Solution Approach 2:
The back-pressure supplying groove acts as an intermediary channel that supplies refrigerant from the first back-pressure space to the second back-pressure space. This controlled intermediary pathway regulates refrigerant flow and pressure distribution, preventing excessive pressure buildup that would increase sliding resistance.
2Force
If the back-pressure chamber pressure is increased to urge the movable scroll toward the fixed scroll, then compression force is improved, but sliding resistance increases
Solution Approach 1:
Different regions of the back-pressure chamber are given different functions through segmentation. The first back-pressure space provides urging force to maintain scroll contact, while the second back-pressure space, accessible via the back-pressure supplying groove, manages pressure to prevent excessive sliding resistance. This local differentiation optimizes both force and operational ease.
3Reliability
If liquid refrigerant accumulates in the back-pressure chamber, then the chamber pressure increases excessively, but this leads to greater sliding resistance and reduced efficiency
Solution Approach 1:
Segmenting the back-pressure chamber into two spaces connected by a supplying groove prevents liquid refrigerant accumulation and excessive pressure buildup. The segmented structure allows controlled vaporization and pressure distribution, maintaining reliable operation without excessive pressure that would reduce efficiency.
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 effectively reduces the increased sliding resistance and prevents excessive pressure buildup in the back-pressure chamber, ensuring efficient operation by discharging refrigerant and maintaining optimal urging force on the movable scroll.
Implementation Method 1
a back-pressure chamber configured such that fluid is drawn into the back-pressure chamber to urge the movable scroll toward the fixed scroll
Implementation Method 2
The back-pressure supplying groove is configured to connect the first back-pressure space to the second back-pressure space, thereby supplying the fluid from the first back-pressure space to the second back-pressure space
Implementation Method 3
The discharge hole is configured to connect the second back-pressure space to the suction pressure space, thereby discharging the fluid from the second back-pressure space to the suction pressure space
Data Source
AI summary
A fixed outer circumferential wall of a fixed scroll, a movable scroll, and a plate define a suction pressure space configured such that fluid flows from a suction chamber into the suction pressure space. The movable scroll and an opposed wall define a first back-pressure space. The plate and a back-pressure-chamber-defining recess of the opposed wall define a second back-pressure space. A back-pressure supplying groove of the opposed wall is configured to connect the first back-pressure space to the second back-pressure space, thereby supplying the fluid from the first back-pressure space to the second back-pressure space. A discharge hole of the plate is configured to connect the second back-pressure space to the suction pressure space, thereby discharging the fluid from the second back-pressure space to the suction pressure space. At least part of the discharge hole is overlapped with the back-pressure supplying groove in an axial direction.