| The scroll compressor is a new generation of energy-saving compressor after pistons screws and other displacement compressors.With its advantages of few parts,high efficiency and low noise,it is widely used in refrigeration,air conditioning and food processing.Applications.The oil-free lubrication scroll compressor is a new field in the development of scroll compressors,which can meet the needs of high requirements for compressive media,and has great development prospects.However,due to the existence of the mechanism error,the meshing clearance of the orbiting and fixed scroll is too large to increase leakage or excessive contact,and under the same clearance condition,the leakage of the oil-free lubricating scroll compressor is more serious than that during oil lubrication,thus affecting the working efficiency of the compressor.Firstly,based on the theory of mechanism and the working principle of scroll compressor,the four-bar model and complex vector equation are used to calculate and analyze the influence of mechanism error on the motion of the orbiting scroll.Secondly,the relationship between the mechanism error and the leakage gap is established.The formula calculates the variation of the tangential leakage gap,the leakage amount and the leakage rate caused by the mechanical error when the crankshaft rotates one circle.Considering the influence of the mechanism error on the orbiting motion and tangential leakage of the scroll compressor,it can not only provide a theoretical basis for improving the compression efficiency and reliability,but also make the scroll compressor better meet the market demand and increase the competitiveness of the market.According to the simplified four-bar linkage mechanism and complex vector equation,the equation of motion of parallel four-bar linkage is established,and the equation of motion of the orbiting scroll under ideal conditions is solved.The motion of the orbiting scroll under ideal conditions is analyzed in detail.situation.Due to the reasons of manufacturing,assembly and post-work wear,the mechanism error can not be avoided.Under the condition of determining the mechanism error of a single bar,the motion law of the orbiting scroll with the mechanism error is calculated,and compared the calculation result with ideal conditions.Due to the actual situation,the way and size of the mechanism error is complex and variable.Therefore,a comprehensive and detailed analysis of all possible conditions of the mechanism error is carried out,and the accuracy of the calculation result is verified by the combination of the theory of mechanism and numerical calculation.The existing research on the tangential leakage of scroll c ompressors is based on the fixed value of tangential leakage gap,but the leakage gap is changed during the actual compressor operation,so the calculation results are not accurate enough.In this paper,the tangential leakage gap calculation formula gained by the general profile theory is used to numerically calculate and analyze the variation law of the tangential leakage gap caused by the mechanism error with the crankshaft rotation.Based on the structural characteristics,motion mode and working principle of the scroll compressor,the thermodynamic model of the scroll compressor is established.The pressure,temperature and density of each compression chamber in the working of the scroll compressor with air compressed medium changing law in the one cycle of the crankshaft motion was calculated and analyzed.The mathematical expression of the tangential leakage and leakage rate when the compressed medium is pure gas i s established.The variation of the tangential leakage and the leakage rate with the mechanism error is obtained.The effect of error on the tangential leakage of the scroll compressor cannot be ignored. |
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