The Tribological Problems Research Of Scroll Compressor Faces Based On Fractal Theory

As a new generation of positive displacement compressor,Scroll Compressor has been paid more attention by more and more domestic and foreign scholars and research institutions in recent years for its advantages of simple and compact structure,small vibration,low noise,high efficiency and energy saving.However,due to the unique internal structure and operation mode of the scroll compressor,there are more friction pairs in the scroll compressor,and the friction and wear at the top and bottom of the scroll has an important influence on the mechanical efficiency and running performance of the scroll compressor.Therefore,the systematic study of the effects of frictional material properties,friction conditions,and contact surface topography on the friction and wear characteristics of the vortex tooth end face,and the study of the friction law of the friction pair during the running-in process,will broaden the application of the compressor and improve its running performance,which provide good experimental basis and theoretical reference.Based on the tribology theory,fractal theory and microscopic contact theory,this paper explores the friction characteristics of the contact surfaces of the scroll vortex top and bottom of a scroll compressor under oil lubrication conditions.The friction wear tests were performed on the paired metal material QT,tin bronze ZQSn5-5-5 and aluminum alloy LD2;the change of the surface topography and the profile curve before and after the wear was observed,and the surface profile curve before and after the wear was observed.Fractal characterization;collection of friction coefficient time series curve during running-in process,analysis of fluctuations of initial friction coefficient and wear time and the variation of fractal dimension of local time series curve;comparison and analysis of PV value on friction coefficient of different paired friction pair Influence;combining the unique internal structure and operation mode of the scroll compressor and analyzing its microscopic contact,based on fractal theory and microscopic contact model of tribology,the fractal calculation model of scroll tip friction during oil lubrication is established.The results show that the change of surface profile height of friction pair before and after wear is determined by the surface roughness and material hardness.Fractal characterization of the profile curve can effectively evaluate the wear degree of the friction pair surface.The friction factor time series has a statistically accurate The phenomenon of periodicity and translational self-similarity has a typical fractal feature.Through the fractal calculation of the friction coefficient time series,it accurately reflects the complexity of the fluctuation of the friction factor during different break-in period,so as to effectively evaluate the running stability of the machine.When compared with the same material,the friction coefficient of the soft material is relatively small but greatly affected by the PV value.The friction coefficient of hard materials is large and increases slightly with the increase of PV value.Make a reasonable selection of materials for the fixed scroll and the scroll to achieve the vortex Rotary disk running stability,reduce the friction factor and extend the life of the scroll.