Hermetic compressor and refrigerator
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Solution Overview
Problem
Hermetic compressors face challenges in improving lubricity and compression efficiency while reducing sliding loss, as the existing designs often result in increased contact friction and inadequate lubrication due to the larger sliding area of the piston.
Innovation Solution
The design incorporates a piston with a columnar seal section, extension sections, and a capture section, where the extension sections have circular arc faces matching the seal section's radius, and the capture section extends further towards the bottom dead center with a smaller radius, reducing the sliding area and enhancing lubrication by optimizing the piston's geometry and lubricating oil distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the piston has a larger sliding area to improve lubricity, then lubrication is enhanced, but sliding loss increases
Solution Approach 1:
The piston is divided into distinct functional sections: a seal section for lubrication, extension sections for structural support, and a capture section for oil retention. This segmentation allows each part to perform its specific function optimally without compromising the other, resolving the contradiction between lubricity and sliding loss.
Solution Approach 2:
Different sections of the piston have different radii and functions. The seal section has a larger radius for better lubrication contact, while the capture section has a smaller radius to reduce sliding area. This local differentiation allows the piston to achieve both good lubricity and reduced sliding loss simultaneously.
2Loss of energy
If the piston geometry is optimized to reduce sliding area, then sliding loss is reduced, but lubrication effectiveness decreases
Solution Approach 1:
The capture section is designed to retain lubricating oil in advance before the piston reaches the lubrication zone. This preliminary oil retention ensures that oil is available for effective lubrication when needed, without requiring a larger sliding area throughout the entire piston.
Solution Approach 2:
The extension sections act as intermediaries between the seal section and the capture section, providing structural support while allowing the oil-retaining capture section to have a smaller radius. This intermediary structure enables both reduced sliding loss and maintained lubrication effectiveness.
3Strength
If extension sections are added to the piston, then structural support is improved, but device complexity increases
Solution Approach 1:
The extension sections serve multiple functions simultaneously: they provide structural support, maintain the piston's mechanical strength, and contribute to the overall geometry that enables both lubrication and oil capture. This multi-functionality reduces the need for additional separate components.
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 improves lubricity and compression efficiency while significantly reducing sliding loss, maintaining hermeticity and enhancing the overall performance of the hermetic compressor and refrigerator.
Implementation Method 1
lubricating oil passes through the oil supply hole, and fills a gap between the outer peripheral face of the piston and the inner peripheral face of the cylinder chamber. This lubricating oil lubricates the portion between the piston and the cylinder chamber, and seals the cylinder chamber
Data Source
Figure 1
Figure 2~3A
Figure 3B~4
AI summary
A hermetic compressor (100) includes an electric element (110), a compression element (112), and a hermetic container (102). The compression element includes a shaft (118), a cylinder block (124), a piston (136), a connection section (144), and an oil supply mechanism (130). The piston has a columnar seal section (160) in sliding contact with an inner peripheral face of the cylinder, two extension sections (162) that have circular arc faces each having the same radius as a radius of the seal section and extend from the seal section to the bottom dead center side in the axial direction with a circumferential gap therebetween, and a columnar capture section (164) that extends further toward the bottom dead center side than the extension section and has a smaller radius than the radius of the seal section.