Scroll Compressor Back Pressure Fluidic Connection Design
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Solution Overview
Problem
Existing scroll compressors face challenges in maintaining optimal back pressure levels, leading to axial gaps, increased friction losses, and reduced efficiency due to inadequate axial force compensation, which affects the compression of refrigerants in vehicle air-conditioning systems.
Innovation Solution
A scroll compressor design with strategically positioned fluid connections between the back pressure chamber and compressor chambers, allowing for self-regulating axial force compensation and optimal pressure adjustment, minimizing leaks and friction losses through dynamic fluidic connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the back pressure chamber is designed to generate high axial force to prevent axial gaps and leaks, then sealing performance is improved, but friction losses and wear of spiral walls increase significantly
Solution Approach 1:
The back pressure chamber pressure is made dynamically adjustable through fluid connections that allow pressure equalization between the back pressure chamber and compressor chambers. This enables the axial force to adapt to operating conditions, preventing excessive friction while maintaining adequate sealing when needed.
Solution Approach 2:
The pressure parameter in the back pressure chamber is changed from a fixed high value to a variable value that can equalize with compressor chamber pressure. This parameter change allows the system to reduce axial force under normal operation (reducing friction) while maintaining sealing capability when pressure differences arise.
2Reliability
If the back pressure chamber pressure is increased to maintain axial contact between scrolls, then axial sealing is improved, but the system becomes less adaptable to different operating points
Solution Approach 1:
The fluid connections create a feedback mechanism where the back pressure chamber pressure responds to pressure changes in the compressor chambers. This feedback allows the axial force to automatically adjust to different operating conditions, maintaining both sealing and adaptability.
Solution Approach 2:
The system transitions from a static high-pressure back pressure chamber to a dynamic system where pressure equalization occurs through fluid connections. This dynamic behavior enables adaptation to various operating points while maintaining axial sealing when required.
3Adaptability or versatility
If flow-regulating components are added to adaptively adjust back pressure level, then adaptability to different operating conditions is improved, but device complexity and mounting complexity increase
Solution Approach 1:
The patent removes complex flow-regulating components from the system and replaces them with simple fluid connections (bores) that provide adaptive back pressure control. This extraction of unnecessary complexity maintains adaptability while significantly simplifying the device structure and mounting process.
Solution Approach 2:
The fluid connections enable the back pressure chamber to self-regulate its pressure through direct communication with the compressor chambers. This self-service mechanism eliminates the need for external flow-regulating components, reducing device complexity while maintaining adaptive capability.
4Device complexity
If axial force compensation is insufficient, then device simplicity is maintained, but axial gaps occur leading to increased friction and reduced efficiency
Solution Approach 1:
The patent uses pneumatic principles through fluid connections (bores) to transmit pressure equalization forces from the compressor chambers to the back pressure chamber. This pneumatic mechanism provides adequate axial force compensation without complex mechanical components, maintaining simplicity while reducing friction losses.
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
The solution ensures consistent optimal pressure levels across all operating points, reducing leaks, friction, and wear, thereby enhancing the efficiency and longevity of the scroll compressor while maintaining efficient compression of refrigerants.
Implementation Method 1
a first fluid connection equalizing the pressure between the back pressure chamber and a radially innermost compressor chamber is provided
Implementation Method 2
The chamber volume in the compressor chambers reduces from outside to in radially and the pressure of the increasingly compressed medium becomes higher
Data Source
AI summary
A scroll compressor of an electrical refrigerant drive contains a housing having a low-pressure chamber, a high-pressure chamber, compression chambers and a counter-pressure chamber. A stationary scroll has a base plate and a spiral wall, the base plate of the stationary scroll delimits the high-pressure chamber. A movable scroll has a base plate and a spiral wall which engages into the spiral wall of the stationary scroll and forms the compression chambers with the spiral wall. The base plate of the movable scroll delimits the counter-pressure chamber. A first fluidic connection is provided which connects the counter-pressure chamber to the radially innermost compression chamber, and the first fluidic connection is located in a positioning region of the radially innermost compression chamber between 75° to 195° following the merge angle.