Study On The Meshing Characteristics And Working Mechanism Of Disc Sealed Single Screw Pump

Screw pump has wide application scope,and has good engineering adaptability and economic practicality.Because of its large displacement,compact structure,strong adaptability of medium,good wear resistance,and especially suitable for high viscosity and multi impurity fluid,the disc sealed single screw pump has a wide application space which developed from screw pump.However,due to the lack of open basic theoretical research,it has seriously hindered the upgrading,optimization and application of the pump.This paper focuses on the basic theory of the working mechanism and meshing characteristics of the disc sealed screw pump.On the basis of its working principle,using the principle of space meshing and the theory of coordinate transformation,the equation of the surface of the meshing pair is established,and the influence mechanism of the parameters of each meshing pair on the meshing characteristics is studied.It is found that in the working process of the pump,the lower half of the sealing disc will be worn first,and the angle of each meshing is less than 30 degrees.The sealing disc is in the state of overall dispersion and partial concentrated wear.On the basis of this,the machining mechanism of the meshing pair is analyzed,and the machining process of the moving rotor forming method is obtained.The wear condition of the seal disc is consistent with the theoretical analysis.According to the meshing characteristics of the disc sealed single screw pump,a numerical model of theoretical displacement is established in this paper,and the results are verified by the engineering value.The error is not more than 6.5%and the pump discharge process is stable and without fluctuation.The influence of the structure parameters on the discharge characteristics is analyzed by the above calculation model.The radius of the screw and the center distance should be taken as the key design parameter,and the pump discharge will reach the maximum when they are equivalents.The leakage mechanism of the pump is analyzed based on the flow relationship of the pump cavity in the disc sealed single screw pump.The leakage model of the gap between the bucket wall and the seal line is established by using the fluid mechanics equation and the flow model,at the same time,the suction capability of the pump in the working process is studied.The results show that the disc sealed single screw pump has a good suction capability.The capacity of theoretical pumping medium can reach 3.54×10~3 kg/m~3 or the speed can rise to 1150 r/min.Finally,the flow pattern in the pump cavity is simulated by the Immersed Solid method of ANSYS CFX,which reveals the forming process of the internal flow field and the changing law of the stable working state and the characteristics of each leakage area.The leakage area caused by the bucket wall gap is the largest,the sealing line gap belongs to the intermittent leakage and the leakage in the return range almost always exists.The leakage of the pressurized zone caused by the gap of the sealing line accounts for 1.44%of the total displacement.This study provides a theoretical support for the performance analysis and performance optimization of the disc sealed single screw pump,and has important significance for its application and popularization.