Increased performance and noise reduction by reducing weaving machine vibrations
Modern shedding machines enable high weaving machine speeds and thus high productivity. However, this potential can often not be fully exploited, as strong vibrations occur in the drive train of the shed formation during high-speed operation. The vibrations in the drive train of the shedding system entail, among other things, high costs due to heavy wear of the weaving harness, increased maintenance costs and high noise pollution. As a countermeasure, the machine speed is usually lowered in practice, which means that the theoretically possible productivity of the machine is not achieved.
In a joint research project (AiF-No. 15476 N) of the Institute for Mechanism Theory, Machine Dynamics and Robotics (IGMR) with the Institute for Textile Technology of the RWTH Aachen (ITA), the oscillating motions at various elements of a formation test bench and at the shedding unit of an air jet loom were analysed. For this purpose, measurements were carried out on the real system (see Fig. 1) and a simulation model of the vibration system was created. Increased performance and noise reduction by reducing weaving machine vibrations.
A multi-body simulation model was created to simulate the system behavior. In addition, the elasticity of various thin-walled structures was taken into account by integrating modally reduced FE models (see Fig. 2). This makes it possible to not only model the machine's strong-body behaviour, but also to calculate the structural oscillations for transient excitation.
The parameters required for the model were obtained from the design data and measurements (modal analysis). By means of measurements for operational vibration analysis, the simulation model was subsequently verified by comparing the measured values with the simulation data and its suitability for the analysis of the vibration behaviour was verified.
With the help of the verified simulation model, it was then possible to investigate the system behavior in more detail, since it was possible to make statements about the movement behavior of components that could not previously be measured. Finally, it was also possible to improve the system's behavior by means of corresponding optimization algorithms without having to produce a large number of expensive prototypes. Finally, the combination of measurements and simulations enabled effective measures to be developed for vibration reduction in the specialized training section and noise reduction on weaving machines .
This project clearly shows the possibilities that arise from the combination of modern simulation methods for the analysis of machine dynamics with classical transmission and mechanical engineering. For example, an optimized motion design can improve system behavior .
Selected publications on the topic:
1. Hehl A., Rosiepen C., Schenuit H., Gries T., Allmendinger F., Corves B.: Final report on the AiF research project 15476 N "Increased performance and noise reduction in weaving mills by reducing weaving machine vibrations" 2010
2. Hehl A., Allmendinger F., Corves B., Gries T.:"Schwingungsreduktion im Fachbildungsstrang", conference proceedings for the 13th Chemnitzer Textiltechnik Conference 2012, ISBN: 978-3-9812554-7-8, p.: 67-74.
3. Schenuit H., Allmendinger, F., Rosiepen C., Corves B., Gries T.:"Vibration reduction in the beam system of the weaving machine", Proceedings of the 3rd Aachen-Dresden International Textile Conference: Aachen 2009
4. Hehl A., Schenuit H., Gries T., Allmendinger F., Corves B.:"Vibration reduction in the specialist training strand", Melliand Textilberichte 2011, p.: 252-254