Research On The Dynamics Performance Of A Filament High-speed Winding Head System

The winding is an important process in the filament production, Winding rotor (or spindle) together with the yarn package constitutes a rotor system. In order to maintain a constant winding speed in spinning, the revolving speed of the rotor has to be gradually slowed down with the increase of the winding diameter, which constitutes a parameters slow time-varying system of its mass, stiffness and revolving speed. The filament winding head is a typical form of the rotor system with parameters slow time-varying. In order to develop new products with new technology, reduce costs and adapt to the new requirements, it is an inevitable trend to develop and product new chemical fiber filament winding heads for high speed of winding with the large package.The full package weight of a filament winding head is generally more than4times its own weight of the spindle. In a winding cycle, the range of the spindle working speed is varying from20000r/min. to4000r/min., which can meet the technological requirements of a spinning speed up to6000m/min.. In the case of the mass and rigidity time-varying, in a wide range of its working speed, how to ensure the spindle system effective working avoiding the critical speed disturbance and to maintain its smooth operation is the key point of the winding head design. In an idle spindle, it has been in a state of equilibrium. When the paper spool is loading, the package wound is increasing, and the compression roll pressing on, they are all disturbing the filament winding effectively. In order to ensure the spindle system working smoothly and to solve all above problem of the winding head design, the main research work is the following:Start with the elastic support system of the winding head, we built a rotor testing device with the same elastic support system of the spindle and then further established a finite element model of the rotor beam element. By means of theoretical and experimental analysis, we studied the dynamic characteristics of the rotor system. The results show that: the elastic support system cause the critical speeds corresponding to the first orders non-bending mode of the rotor system (motion of the elastic support rigidity shaft) decrease significantly, which lead to a relatively wide range of small variation between the lower order critical speed and the higher order critical speed (according to the smooth running condition).Secondly, dynamic parameters of the elastic support system involve in many uncertain factors. In this paper, we obtained the equivalent stiffness and damping through the test. In addition, through the analysis of non-bending vibration mode of the rotor with elastic support, as well as the corresponding critical speed, we improved the test method for stiffness of the elastic supporting system, and gave the parameter selection requirements of the rotor system when calculating dynamic parameters of the elastic support system by test.Based on the rubber material stress-strain relationship, we established its constitutive relation by applying phenomenological theory, and achieved linearization within the work area. Based on Hertzian contact theory, we established a mechanical model of the rubber ring support, and analyzed its static characteristics of the rubber ring by the finite element method. Through the test of the rotor’s different mass, we obtained a series of equivalent dynamic stiffness value of the elastic support system and some corresponding fitting curves, and analyzed characteristics of the elastic support. At the same time, the finite element model of the rotor system was established and analyzed. The results show that: the solution of the theoretical calculation and the experimental data agree well, which proves the correctness of the design.Then, in order to verify theoretically the characteristics of the automatic centering of a high-speed rotating rotor with elastic support, a kinetic equation for a rigid rotor with elastic support was established. In addition, a finite element model for a rotor system with elastic support was established, and the rotor is used a solid element. The analytical results show that:changing the radial stiffness of the elastic support can significantly change the critical speed of rotation corresponding to the elliptic cylindrical movement mode of the rotor. While, at the same time, changing the axial stiffness of the rotor elastic support can significantly change the critical speed of rotation corresponding to the elliptical conical motion mode of the rotor. By changing two groups of the stiffness of the rotor system, the critical speed corresponding to non-bending the mode can be adjusted to a required range. When the package on a single chuck continues to grow, and chuck and spindle lengths increase, the critical speed corresponding to a bending mode will decreasing, which will narrow the range of working stability. In order to rational plan the critical speed value, this paper presents an active regulation method of the rotor critical speed, and gives some suggestions further.Lastly, based on a typical filament winding head, we designed the corresponding virtual prototype, and established a finite element model. Using the above method and the analysis results, we conducted the calculation, simulation and analysis about the dynamics behavior of the acceleration of the spindle empty package, deceleration of the full package and winding parameters slowly variations etc, which reveals different dynamic characteristics of the three stages. The results verify its correctness and feasibility.