Design and contact characteristics analysis of a new internal twin-screw pump

This paper designs a new internal meshing twin-screw pump (new twin-screw pump). To study the new twin-screw pump in the principle, performance parameters, and contact characteristics of the differences with the single-screw pump, the mathematical method of motion conversion is used to convert the planetary motion of the single-screw pump into the fixed-axis rotation of the internally intermeshing twin-screw pump. It is found that the movement relationship of the two pumps is similar. When the structural parameters of the two pumps are the same, the flow per revolution of the single-screw pump is N+1 times that of the new twin-screw pump. To obtain the force transmission characteristics in the internal meshing process, a numerical method was used to analyze the structure of the new twin-screw pump statically. Due to the existence of the meshing relationship, the influence of the screw meshing fit clearance, progression, and pitch on the contact stress is further explored. The results of the study show that the internal and external rotor contact stresses show a trend of small in the middle and large at the ends, the stress distribution coefficient [Formula: see text] increases with the increase of the mating clearance, and the stress distribution becomes uneven with the increase of the number of screw stages and pitch. The results of this study provide a basis for the reasonable selection of structural parameters of the new twin-screw pump.