Study On The Dynamic Characteristics Of Planetary Gear Transmission Mechanism Of Metal Cold Rolling Mill

Due to its outstanding advantages of small size,large transmission ratio,high transmission efficiency and strong ability to bear heavy loads.It has very important uses in many industries,such as wind power generation and so on.Cold rolling mill is an important equipment for cold rolling of seamless steel pipes.As society develops,people have more stringent requirements for the precision and quality of seamless pipes,which has led to the need for the cold rolling mill to operate smoothly at high speeds,and its transmission system is a key part of the cold rolling mill to ensure that it can work smoothly at high speeds.In contrast to traditional crankshaft-driven mills,which produce irregular oscillations in the vertical direction due to tension,resulting in increased wear and noise,this paper addresses this problem by designing a planetary gear reducer with reciprocating linear motion of the output shaft.In this paper,the theoretical analysis and calculation of kinematics of the designed planetary gear reducer and the construction of the dynamic theoretical model are carried out,the dynamic differential equation is derived,and the force of each component of the system is solved,and the motion law and dynamic characteristics of the system are simulated and analyzed by combining the virtual prototype simulation technology.In addition,the influence law of counterweight block on the inertia force and inertial torque of the output shaft of the system,as well as the influence law of different speeds of the drive wheel on the inertia force of the output shaft of the system,solves the quality problem of the cold rolling pipe mill caused by vibration,reduces the noise,prolongs the service life,and thus realizes green and efficient production.The main research contents and results of this paper are as follows:(1)The working principle of the output shaft of the reducer that can present reciprocating linear motion is studied.The structural design of the planetary gear transmission system was carried out,and the three-dimensional solid model of the planetary gear transmission system was constructed.Based on the theory of mechanical principles,calculations related to dynamics are carried out.Such as angular velocity relationship and force relationships.(2)Using the planetary gear mechanism as the model,the "concentrated parameter" method is used to construct a coupled translational-torsional dynamics model based on mechanical vibration theory,taking into account three degrees of freedom along the radial direction and axial direction of each component.Research relevant theoretical knowledge.(3)Based on Adams virtual prototype simulation technology,a dynamic simulation model of planetary gear drive system is constructed,and the kinematic law and dynamic performance of the system are simulated and analyzed.The results show that the speed of the active wheel is stable at157.00rad/s,which is consistent with the theoretical calculation value,and the speed of the big gear and the planetary gear shows a trend of up and down,but it is basically stable at 26.00rad/s and 26.10rad/s,and the relative errors are 0.12%and 0.50%,respectively,compared with the theoretical value,which are small.The meshing force between the high-speed stage and the star-rated meshing gear pair fluctuated up and down around 7939.63 N and 343.40 N,respectively,and the relative errors were 0.20% and 0.05% respectively compared with the theoretical values,which verified the rationality of the simulation.(4)The effects of the presence or absence of counterweights and weights of different thicknesses on the inertia force and inertial torque of the output shaft of the planetary gear drive system were studied.The results show that after adding the No.1 and No.2 counterweights,the rms values of the inertia force and inertial torque of the output shaft of the system are 26140.38 N and25885.70N·m,respectively,which are reduced by 26.59% and 39.56%compared with the non-counterweight,and the balancing effect is obvious.At the same time,different thickness counterweight block on inertia force and inertia torque balance effect is also different,when the thickness of No.1 and No.2 counterweight blocks are 125.00 mm,130.00 mm,has achieved a good balance effect,continue to increase the thickness of the counterweight block will make the total weight of the system significantly increased,occupy a large space,but also affect the coordination of the entire transmission mechanism,so the thickness of the counterweight should be reasonably selected.