Study On Micro Clearance Leakage And Lubrication Performance Of Back Pressure Chamber Of Electric Scroll Compressor

With the concept of energy conservation and emission reduction deeply rooted in the hearts of people,electric vehicles have ushered in an unprecedented development opportunity,and the core component of the air conditioning system of electric vehicles,scroll compressor,has become a research hotspot.Electric vortex compressor dynamic vortex disk back and support the micro gaps between body,in the normal operation of electric vortex compressor,back pressure in the cavity part of lubricating oil will be through dynamic vortex disk and bracket of annular clearance leakage between body,this will lead to change of back pressure back pressure in the cavity,the lack of back pressure or metropolitan influence on the performance of the scroll compressor of electric machine,if the back pressure is insufficient,will cause the dynamic and static vortex disk separation along the axial direction,which resulted in increased refrigerant leakage,lowering the compression performance of the compressor;If the back pressure is too large,it will cause the dynamic and static scroll to close,friction loss.Therefore,it is very important for the good operation of the electric scroll compressor to reduce the leakage of lubricating oil in the micro clearance of the back pressure chamber and improve the lubrication performance of the micro clearance of the back pressure chamber.In this paper,the micro clearance leakage model of the back chamber of the electric scroll compressor is established by using the N-S equation and the flat plate theory.Numerical simulation method is used to simulate and calculate the leakage of the micro clearance in the back pressure chamber.At the same time,a reasonable surface microtexture was designed on the surface of the support body.Firstly,Soildworks was used to establish the calculation domain model of the micro-clearance in the back-pressure chamber of the electric scroll compressor,then ICEM CFD was used to conduct structured grid division in the back-pressure chamber micro-clearance calculation domain,and finally Fluent was used to conduct numerical simulation in the back-pressure chamber micro-clearance fluid domain.At the same time in the back pressure cavity gap design various types of round pit support body surface micro texture: part mainly has the texture,texture and complex texture,separately carries on the numerical simulation,to solve the small gap of the back pressure cavity leakage and oil film pressure distribution,to calculate the maximum bearing capacity of oilfilm,finally through the comparison and analysis,can reduce the clearance leakage and to improve the performance of micro gap lubrication micro surface texture of geometrical parameters,arrangement form and texture types.The results show that the formula for calculating the amount of micro clearance leakage in the back pressure cavity derived from the N-S equation and the plate theory is consistent,and the results are in good agreement with the numerical simulation results of Fluent.Under the condition of a certain clearance value,the greater the inlet pressure value of lubricating oil in the back pressure chamber,the greater the leakage quantity;The maximum bearing capacity of the oil film decreases with the increase of the microgap when the surface texture of the support is designed.When the surface of the bracket is designed with partial texture,the larger the diameter of the circular cavity,the better the sealing and lubrication performance of the micro-clearance of the back-pressure cavity,and the deeper the circular cavity,the better the lubrication performance of the micro-clearance of the back-pressure cavity.The depth of the circular cavity is 0.007 mm,and the lubrication performance of the micro-clearance oil film is the best.By comparing the four different types of texture leakage and lubrication,it is found that the leakage of the external texture is the smallest and the dynamic lubrication is the best.When the surface of the bracket is designed with composite texture,only the combination of the diameter of the inner and outer rings and the combination of the depth of the inner and outer rings can be reasonably arranged,so as to obtain good sealing and lubrication performance of the micro clearance of the back pressure chamber.The conclusions obtained in this paper can provide reference for the design of the micro clearance structure and the study of the surface texture of the back pressure chamber.