Numerical Study On Characteristic Of Gas Bearing And Clearance Seal In Linear Compressor

With the development and application demand of modern technology, cryogeniccryocooler is rigidly demanded for long life, low noise, higher efficiency, higher reliabilityin fields of aeronautics and space and military. With the advantages of compact structure,little or no moving-part, small volume and high efficiency, linear compressor has beenreceived more and more attentions from relevant researchers. To prolong life andimprove reliability of linear compressor，it is critical to make sure that all inner partsrealize no-contact operation. Through coordination of planar spring、gas bearing andclearance seal，linear compressor achieves no-contact lubrication between cylinder andpiston; What is even more important is the fact that possibility of refrigerant contaminatedby lubricant oil is greatly reduced. It is of much important significance for stirlingcryocooler and pulse tube cryocooler. In this paper, characteristic of gas bearing andclearance seal were simulated based on gas lubrication theory, the main contents includesthe aspects as follows:First of all, the present research situation of linear compressor key technology athome and abroad was introduced. And after research achievements were summarized, thecurrent existing problem about application and investigation of linear compressor wasanalyzed. On that basis, the research content, theory knowledge and problem to be solvedwas put forward. Meanwhile, main topic and significance of this paper was stated.Then, mathematical model of gas bearing in linear compressor was derived andestablished from gas lubrication theory. Research of gas bearing was simulated by Fluent,static and dynamic load bearing characteristic of gas bearing was analysed; and effects ofgas bearing’s structural parameters and operating conditions on load characteristic wasdemonstrated theoretically. Thus structure configuration and operating conditions of gasbearing was optimized.And then, clearance seal theory of linear compressor was carried out. On that basis, mathematical model of clearance seal in linear compressor was established; furthermore,main factors affecting performance of clearance seal was analysed. For different gap sealtypes, with the optimization of structural parameter and operating conditions, the firstparameters were achieved; and for the numerical results the theoretical demonstration wasgiven out accordingly, which provided valuable reference to clearance seal in linearcompressor.Finally, according to the application of gas bearing and clearance seal technology inlinear compressor, the comprehensive experiment prototype model of gaslubrication and clearance seal between cylinder and piston was developed, on which wecould carry out the relevant experimental study on the performance of gas bearing’s loadcapacity and clearance seal. Fundamental experimental scheme, experimental standard andtesting system were proposed.