Abstract: Aiming at the problem that the stator of the screw pump was prone to wear and fail in the process of oil production, the friction characteristics of the conventional stator of the screw pump and the stator with constant wall thickness were studied. Firstly, the thermalmechanical coupling simulation of the two stators was carried out by using the finite element analysis software. Then the frictional stress state of the two stators in the working process was analyzed, as well as the influence of the interference and temperature on their frictional performance. Finally, the frictional characteristics of the two stators were analyzed. A comprehensive comparison was carried out to analyze the suitable working range of the two stators in the range of interference and temperature respectively. The research results show that comparing with the conventional stator, the friction stress distribution of the stator with equal wall thickness is more uniform; with the increase of the interference and temperature, the frictional stress of the two stators shows a gradual increasing trend. When the temperature is lower than 0.3mm and the temperature is higher than 40℃, the friction performance of the stator with constant wall thickness is better than that of the conventional stator. The comparative study of the friction characteristics of the two stators has a certain reference value for the optimization of the stator structure design and the selection of the stator style under different working conditions.

Key words:  positive displacement pump; screw pump stator lining; friction performance; wear failure; frictional stress state; thermomechanical coupling simulation