Dynamic Characteristics Analysis Of Rotor Spiral Surface Milled By Disc Milling Cutter

In the petroleum industry,with the increase of exploitation time and the decrease of pressure in the oil well,the difficulty of oil exploitation is doubled.At this time,external equipment is needed to boost the pressure in the oil well.Screw pumps and screw drilling tools are widely used in oil pumping because of their excellent boosting performance.As the core component of the screw pump and the screw drilling tool,the screw rotor plays an important role.Its surface quality and accuracy seriously affect the working efficiency and service life of the screw pump and the screw drilling tool.In this paper,the dynamic characteristics of disc milling cutter in milling helical surface of rotor are analyzed,the mathematical model of milling force is established,and the correctness of the theoretical model is verified by simulation analysis.At the same time,the modal of disc milling cutter and screw rotor under various conditions is analyzed,the dynamic model is established,and the modal test and milling vibration test are carried out to fully grasp the dynamic characteristics of the processing process of screw rotor.Follow-up optimization of machine tool structure and other work provides a theoretical basis.Firstly,the cutting mechanism of disc milling cutter milling screw rotor is studied.According to the right angle cutting theory and oblique angle cutting theory,the mathematical model of milling force is established and the influence of process parameters on milling force is analyzed.A simplified three-dimensional model of disc milling cutter and screw rotor is established.On this basis,the milling force is simulated and analyzed.Then the theoretical analysis results are compared with the simulation results to verify the correctness of the theoretical model.Secondly,according to the actual processing situation,the modal analysis of disc milling cutter in free state and assembly state and screw rotor in different parameters is carried out by finite element simulation software,and the stress nephogram and mode diagram are obtained,and the influence of geometric parameters on the natural frequency of the screw rotor is analyzed.Finally,the dynamic model of milling is established,and the modal tests of the free state and assembly state of the disc milling cutter and the fixed state of the screw rotor end are carried out by force hammer excitation method.The frequency response function and correlation curve of the disc milling cutter and the screw rotor are obtained,and the modal parameters are extracted.The experimental results are compared with the simulation results to verify their correctness.Vibration tests under different milling parameters were carried out to analyze the vibration state of the disc milling cutter in the process of milling screw.The influence of milling parameters on milling vibration was studied by using the control variable method.