Linear Compressor Piston Coating for Low-Friction Compact Operation
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Solution Overview
Problem
The existing linear compressor has a large volume, which occupies excessive space in the machine room of refrigerators, and its manufacturing process is costly due to complex and separate processes for surface treatments, leading to potential friction and abrasion issues during operation.
Innovation Solution
A linear compressor with a piston surface treatment comprising a first surface treatment part of chromium nitride and a second surface treatment part of diamond-like carbon, applied using vacuum deposition processes, to reduce friction and abrasion, and a gas bearing system to minimize oil-related friction, with the manufacturing process streamlined to reduce costs and improve surface treatment performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the linear compressor size is reduced to increase refrigerator storage space, then the volume of the machine room is reduced, but the compression performance deteriorates due to increased friction from oil circulation at higher drive frequencies
Solution Approach 1:
The patent replaces the traditional oil-based lubrication system with a gas bearing system that uses refrigerant gas for lubrication. This substitution eliminates the harmful effects of oil circulation friction that worsen at high drive frequencies, allowing the compressor to maintain reliable performance even when miniaturized and operated at higher frequencies to compensate for reduced size.
Solution Approach 2:
The patent changes the lubrication parameter from liquid oil to gaseous refrigerant. By introducing refrigerant gas into the compression chamber to form a gas bearing, the system transforms the lubrication mechanism from liquid-film lubrication to gas-film lubrication, which reduces friction and allows high-speed operation in compact compressors.
2Reliability
If complex separate processes are used for surface treatments on the piston, then the friction and abrasion resistance is improved, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple separate surface treatment processes into a single integrated vacuum deposition process. By forming both the chromium nitride layer and the diamond-like carbon layer in one continuous vacuum deposition operation, the manufacturing cost is reduced while maintaining the friction and abrasion resistance benefits of multi-layer surface treatment.
Solution Approach 2:
The patent applies composite surface treatment with two distinct layers: a chromium nitride layer providing corrosion resistance and a diamond-like carbon layer providing low friction and high wear resistance. This composite structure achieves superior friction and abrasion resistance compared to single-layer treatments, while the vacuum deposition method keeps manufacturing costs manageable.
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 compressor's reduced size increases storage space in refrigerators, improves compression efficiency by minimizing friction, and simplifies the manufacturing process while enhancing surface treatment durability and performance.
Implementation Method 1
a first surface treatment part of chromium nitride and a second surface treatment part of diamond-like carbon, applied using vacuum deposition processes
Implementation Method 2
a gas bearing system to minimize oil-related friction
Data Source
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AI summary
A linear compressor and a method for manufacturing a linear compressor are provided. A piston of a linear compressor may include a surface treatment body made of aluminum or an aluminum alloy; a first surface treatment provided on an outer surface of the surface treatment body by a first vacuum deposition process; and a second surface treatment provided on an outer surface of the first surface treatment by a second vacuum deposition process.